Detailed report of mites from the 1940s

[Guest guest]

Found a very interesting article. I read it w/ great interest.

Perhaps we can use the info here.

http://members4.boardhost.com/Kritters/msg/2040.html

Proceedings of the Entomological Society of Washington

Vol. 53, February, 1951, No. 1.

Unusual Scalp Dermatitis in Humans Caused by the Mite,

Dermatophagoides (Acarina, epidermoptidae)

By Jay Traver, Department of Zoology, University of Massachusetts,

Amherst

The writer and two other members of her immediate family, all of us

adult females, have been for the past several years the unwilling

hosts to the mite, Dermatophagoides scheremetewskyi Bogdanow. Since

the published reports on this mite as a parasite of humans are not

numerous, it seems desirable to present an account of the activities

of the mite from first hand information. Symptoms, treatment

employed in the attempt to control or eradicate the mite, reaction

of certain members of the medical profession to this problem, and

the present status of the situation are therefore set forth.

It is to Dr. Baker of the Division of Insect Identification,

Bureau of Entomology and Plant Quarantine, Washington, D.C., that we

owe the identification of this mite, and the synonymy herewith is

presented. It is to him also that the writer owes her contact with

Dr. Gaines W. Eddy of the same Bureau in Washington, who has

suggested the use of certain new synthetic organic compounds as

scabicides in the treatment of this mite. Had it not been for Dr.

Baker's interest in this problem, expressed in personal

correspondence, it is quite possible that no attempt would have been

made to publish this personal account of an infestation with the

mite Dermatophagoides.

Personal Observation of the Activity of the Mite.

Small itching red papules on the scalp were noted as early as 1934.

This condition persisted without much change in spite of sporadic

efforts to control it, until the spring and early summer of 1943. At

this time, the sensations as of some arthropod crawling, scratching

and biting became very pronounced, and occurred over wide areas of

the scalp. The idea that Pediculus humanus capitus might be the

causative agent was not borne out since at no time was it possible

to 'comb out' a louse nor to locate nits on the hairs. Further, the

infestation did not yield to treatment known to be effective against

pediculosis. The itching and crawling sensations were most

pronounced between 10 p.m. and the early hours of the morning.

By the middle of August, 1943, the annoyance had become excessive

and more strenuous efforts were made to clear up the infestation and

to locate the causative agent. Three areas of the scalp were

principally involved, a space as large as the palm of the hand above

and behind each ear, and an even larger area on the top of the head

in the frontal region. The sensations as of something biting,

scratching, and crawling from place to place were now almost

continuous, becoming apparent as early as 10 a.m. and continuing all

day and far into the night, increasing in intensity from 11 p.m.

onward. Sound sleep was quite impossible. The principal areas

involved were also painful and swollen, and as was discovered later,

the epidermis over each of them was extremely thickened. On the

suggestion of a druggist, a soap containing 1% mercuric iodide was

employed as a shampoo. This seemed to irritate the mites, which

became very active after the use of this soap. Many of them began to

move down out of the scalp, and some of the thickened epidermis

began to slough off.

Those that continued down on to the body soon became embedded in

itching red papules reminiscent of trombiculid infestations. Treated

with strong sulphur ointment, they apparently did no further damage.

They could be found on the shoulders, under the arms, beneath the

breasts, on chest and both upper and lower back, occasionally around

the umbilicus. The sensations of crawling and biting which were felt

on legs and feet, in the latter case often on but seldom between the

toes, indicated that some of the mites had migrated to the lower

extremities.

Others of the mites, however, moved down on to the face, invading

eyes, ears and nostrils. It was the mites in these locations that

did the most damage. Both eyes became so badly swollen that it was

impossible to move the eyeballs; to look to right or left it was

necessary to move the entire head. Invasion of the eyes was not

confined to the period immediately following the use of the mercuric

iodide soap, but continued for many days thereafter, this invasion

occurring mostly between midnight and 3 a.m. The victim of their

attack would have fallen into a light sleep, when a sharp pin-prick-

like sensation in one eye, followed by an immediate response on the

part of the already badly swollen eye would drive sleep away quite

effectively. The movements of a mite that had entered under the

eyelid could be felt as it crawled slowly about, then began to 'dig

in' at which moment the eye suddenly became even more swollen than

before. An almost continuous flow of lachrymal secretion seemed to

attract the mites and made vision difficult. At no time, however,

was there evidence of the formation of pus in the affected eyes.

Invasion of the nostrils produced quite distressing symptoms, as of

something crawling and scratching in the mucus membrane; ofthen this

accompanied by a distinct irritation of the throat, trachea and

bronchi. Early invasions of the ears seemed confined to the region

of the pinna, in the folds of which the mites burrowed, producing

the usual itching red papules. Their prresence in the ears was the

cause of some concern on my part, as it is well known that certain

species of mites may cause great damage in the ears of small

animals. Apparently we may consider ourselves most fortunate that

his particular mite did not choose to invade the external auditory

meatus, from which location it might easily have pierced the

eardrum. The difficulty of controlling such an infestation in the

ear, had it occurred, is at once apparent, since as yet we have

found no drug that is completely effective against the mites. Even

had such a drug been known, its use in the ears might have been

inadvisable. Unfortunately for humans, medical doctors ar much less

versed in dealing with such situations than are the veterinarians

who care for our dogs and cats.

In addition to the trouble caused directly by the mites, a certain

amount of allergic reaction and probably also of secondary bacterial

or fungicidal reaction were also present. It is difficult if not

impossible to determine how much additional injury and discomfort

may have resulted from these secondary infections.

The most acute phase of the infestation yielded to control measures

within six weeks. Henceforth, the symptoms previously mentioned

became less sever and somewhat chronic, exhibiting an increase in

activity more or less periodically every two and one-half to three

months. This condition has continued up to the present time. Even

this summer (1950) live mites have been taken from all three members

of the family. July and August are their periods of greatest

activity.

In spite of my optimistm in regard to the limited activity of those

mites that invaded the ears, there is still a question as to whether

or not the difficulty I am now having with my ears, and the rather

sudden onset of deafness on the part of the other infested members

of my family, may have been aggravated at least by the presence of

the mites. Likewise, I wonder if the chronic sinusitis to which I

have been heir for some time may also have been increased by those

mites which entered the nostrils.

The much-thickened epidermis had sloughed off from the thre most

heavily infested areas of the scalp before the end of the the period

of acute symptoms, and since that time no such unusual thickening in

these or other parts of the body has been noted. Itching red papules

continue to occur irregularly on the scalp, the pinna of the ears,

on the face, and occasionally on neck chest and back. Such areas

frequently become covered with small incrustations. The mites

succeeded in establishing themselves temporarily on one writst,

between the third and fourth finger of one hand, just below one ear,

on the ventral surface of one knee, and just below the hair line

above the left temple. Applications of 2 to 5% aqueous solution of

gentian to each of these affected areas except the one above the

temple, repeated daily for a week or ten days, finally cleared up

each of these sites of infestation, some of which were reminiscent

of the behavior of scarcoptes scabiei. The network of red lines and

itching swellings above the left temple seems also to have been

brought under control, largely through the use of sulphur ointment

and lysol. There still remain infested areas on the face, in the

upper corner of the lower lip and in the right eyebrow, which have

not yet been brought under control. Tunnels or burrows, presumably

in the dermis, could be seen on the wrist, in the soft skin between

the fingers, on the knee, below the ear, above the temple, and on

the lower lip. On wrist and knee, these burrows took the form of one

or more or less straight central tunnel, visible as a slightly

raised reddish line, from which extended at right angles, several

shorter lateral tunnels. Above the temple, as noted, a network of

raised red lines with small swellings here and there, indicated the

presence of the mites. In other areas mentioned, the tunnels were

more or less U-shaped, somewhat wider at one end, and apparently

without lateral branches. Inasmuch as it has never been possible to

locate a mite in the sloughed-off epidermis or in the small

incrustations which form over infested areas, it seems probable that

the burrows are actually in the dermis. Further evidence for this

belief is the fact that live mites have been captured from the

deeper regions underlying such an incrustation when the latter had

been removed. Certainly, during the period of acute symptoms, when

mites could be felt running about below the thickened epidermal

masses, and causing their host almost to tear off bits of the scalp

in an effort to get at them, none were even inconvenienced by any

substance used against them until the mercuric iodide soap was

employed. One of the most annoying runways occupied by the mites,

the entire length of the right eyebrow, with extensions to and from

the adjacent hairline, does not show on the surface any indication

of its presence save a slight swelling. Even when such a burrow does

not show externally, however, its presence it readily ascertainable

by reason of the activity of the mites, which habitually travel from

one area to another along certain well-defined highways. If these

highways were in the epidermis, it should seemingly have been

possible to capture mites in them, as the mites moved from place to

place.

Symptoms experienced by other members of the family.

It was no until some time after my acute symptoms had subsided that

other members of the family began to feel the effects of the mites.

Whether they were less susceptible to the mites, from whatever

source these were originally obtained, or whether they were infested

from my infestation, we shall never know. As I had not at any time

discussed the details of my symptoms with either of them, it is

evident that they did not develop symptoms 'in sympathy' with mine.

Only now and then, one of them would mention her particular symptoms

as of the moment. One has had more difficulty with mites invading

the pinna of the ear than I have had. These mites, when driven from

the ear by the use of sulphur ointment or some other substance,

moved down on to the body and became embedded there, particularly on

the chest, shoulders and lower back. This member has also had much

trouble with mites invading the nostrils. The other member of the

family had more difficulty with mites embedded on the neck and

shoulders. At no time have either of them suffered acutely from the

presence of the mites.

The medical profession.

Aid was of course sought from the medical profession, but very

little help in treatment for the symptoms was forthcoming from this

source. A reliable oculist who was consulted during the period of my

acute symptoms reported the finding of some foreign objects embedded

in the eye, but as these were apparently not in the cornea, he

thought they would do no serious damage. A dermatologist,

recommended by a local physician, was apparently convinced without

more than a very casual examination, that the patient's symptoms

were largely imaginary, those that did exist having been caused by

an ill-advised attempt on the part of the patient to rid herself of

something that was not there. Not until three days after my visit to

his office, however, did he tell me this. Even he could not fail to

note the greatly swollen eyes and the three areas of thickened

epidermis on the scalp. He X-rayed the eyes and the affected scalp

areas, and recommended several days' stay in the hospital,

ostensibly for further treatment of the eyes. Actually, such

treatment consisted solely of applications of hot boric acid

compresses to the eyes, and theuse of cold boric acid as an eye wash

treatment which I could have rendered myself at home fully as well.

After the third day in the hospital, he turned me over to a

neurologist for treatment of my 'psychoneurotic' condition. The

patient, however, succeeded in convincing the neurologist that she

had no need of his services. The local physician now suggested the

use of sulphur ointment on the scalp, such as had been used

effectively by the patient against mites embedded elsewhere on the

body. She also suggested the use of sulfathiazole, which seemed to

aid materially in reducing the allergic reactions and possible

secondary infections. The complete amazement of this physician, when

she was later shown some of the first mites to be captured,

indicated full well that she, too, had accepted at face value the

dermatologist's diagnosis of 'Just imagination.' Hence any real aid

in the treatment of the scabitic condition, other than the suggested

use of sulphur on the scalp, came from the patient herself or from

parasitologists. It is doubtful if the X-raying of eyes and scalp

had much effect on the mites, although it may certainly have aided

materially in clearing up secondary infections.

Treatment.

To date, no treatment applied has been able to bring about complete

eradication of the mites. However, many substances used on the scalp

and elsewhere on the body have afforded welcome even though

temporary relief from the annoying sensation produced by the mites.

It would seem that a certain number of the substances employed have

actually killed some or all of the adult mites, but have had no

effect on the ova. Any substance used on the scalp was applied with

sterile cotton or with a pipette, usually being then well rubbed in

with the finger tips. Twenty-four to 48 hours was the usual length

of time between the application of any one substance and its removal

by means of a shampoo, although some substances were left on the

scalp for at least a week. The scalp was always shampooed as a

preliminary to the application of any substance, and no other

substance was used until the preceding one had been thoroughly

washed out. After the use of certain of these compounds, a period of

two to three months often elapsed before renewed symptoms indicating

the presence of the mites were apparent. On circumstantial evidence

this might be taken to indicate that the length of time required for

the maturation and hatching of a young mite from the ovum is

approximately two to three months. There is always the possibility,

however, that the young mites may not make their presence felt at

once, and that the growth period is really somewhat shorter.

Attempts at control have continued actively from 1943 up to the

present time.

Many substances employed as a possible means of control proved

useless for that purpose. Among these may be mentioned: DDT powder,

10% used as for pediculosis; kerosene emulsion with vinegar;

Seargant's Mange Cure, which had been of value in treating mange on

two pet cats some years before, but was of no help in the present

situation; ethyl, normal butyl and isopropyl alcohols, used

separately and in varying strengths from 70 to 100%; ether, applied

to the scalp a few drops at a time; 3% phenol, also as used for

pediculosis.

The following chemicals have proved of value in bringing relief,

sometimes of a very temporary nature, from the activities of the

mite:

Sulphur ointment, 15% USP, applied to the scalp or other parts of

the body. This could be left on for several days after application.

It is one of the most helpful substances employed to date. In the

early treatment of mites on the body, a stronger preparation of

sulphur was used, made by mixing flowers of sulphur with Crisco or

Spry. The exact percent of the sulphur so used was never determined.

At one time only during the period of acute symptoms was any

sensitivity to sulphur noticed. The ointment used at that time was

made up in lanolin. This sensitivity soon disappeared and no

indication of it has been felt since that time. Mites treated with

sulphur seem to die in situ.

Gentian violet, 2 to 5% aqueous solution. This, if left on any

affected part of the body for a week or 10 days, and if constantly

augmented by additions of the same every few days, proved completely

effective in eradicating the small colonies already mentioned, on

wrist, knee, fingers and below one ear. Unfortunately it was never

feasible to leave this dye on the scalp for more than two days at

the most, as it is by no means desirable to go about with one's

scalp and hair painted purple. There is also some question as to

whether or not gentian violet would prove as effective over areas in

which the mites were more deeply located or where they had been " at

home " for a considerable period of time.

Lysol, a relatively strong solution (4 teaspoonfuls to the pinte, or

even somewhat stronger) has proved to be one of the most effective

methods of killing the adult mites. It can be used, at this

strength, on small areas only. It has the disadvantage of possessing

a strong odor and is also hard on the skin. The epidermis usually

peels off from any area so treated some time after the use of this

solution. In a weaker solution it has been used over the entire

scalp following a shampoo, usually being rinsed off in a few hours.

It is also by the use of lysol solution that some of the mites have

been captured, as noted below.

Zemo, both regular and extra strength solutions, has proved of value

in reducing the irritation caused by the mites' activities, and may

even have killed some of the adult mites.

Germicidal soap, 1% mercuric-iodide, used as a shampoo, appears to

be quite effective against the mites, but does not eliminate all of

them, nor does it appear to have any effect upon the ova. This soap

is used quite regularly as a shampoo, and since no ill effects have

followed its use except at one period of acute symptoms, it seems

evident that this soap cannot have been the causative substance

which precipitated the acute attack. No evidence of sensitivity to

this soap has been noted. It often causes the mites to migrate,

however, which is not desirable if the migration is toward eyes or

ears.

Zinc oxide ointment. This has been used at times alone or in

combination with sulphur ointment, as is sometimes recommended, to

alleviate itching on areas of the face and neck. Painted around each

eye, it served to prevent the entrance of many mites into the eyes,

as they could be felt moving up to this barrier but going no further.

In addition, certain other compounds known to be of value in the

control of sarcoptic and other forms of mange, have been employed.

Of these, the first two were suggested by Dr. Gaines W. Eddy, who

has recently published the results of a series of experiments with

some new synthetic organic compounds as scabicides (Jour. Investig.

Dermatology 12(2): 117-123, 1949). He likewise sent me samples of

several of these substances, enough for two or more treatments with

each. It seems quite possible at the present writing that one or

both of these new chemicals may eventually prove effective in the

eradication of our mites.

Benzyl salicylate. An aqueous solution of salicylic acid and benzyl

ester 10%, in 2% of Tween 20, is the first of these two drugs.

Samples of the Tween 20 were kindly donated by the Atlas Powder

Company of Wilmington, Del. This has been used on my own scalp for

several different doses during the past two months. After each such

use, the symptoms were temporarily eliminated, but migration of the

mites was quite noticeable. It has recently been employed in the

treatment of one of the members of my family, but living mites are

still present on her scalp.

2-phenylcyclohexanol 10%, and Tween 20, 2% as an aqueous solution,

is the second chemical recommended by Dr. Eddy. The Dow Chemical

Company of Midland, Mich., was kind enough to provide me with

samples of this compound. It has recently been used on my own scalp.

As yet, the results are inconclusive, but again the symptoms are

temporarily alleviated. Migration of mites occurs after its use.

Ultimate success might be achieved by the frequent repetition of

this substance to the scalp and other affected areas, if used

repeatedly over a sufficient period of time so as to kill all newly

hatched larvae before they reach maturity.

Benzyl benzoate. This has been employed in two forms: first as a

liquid, and second as an emulsion, the Wellcome brand, which was

much used by British scientists during World War II in the treatment

of human scabies. Some relief was obtained from its use,

particularly when the emulsion was employed. It seemed especially

effective against those mites which had located in the pinna of the

ears. Migration of the mites after the use of this compound was most

pronounced. Recently, the emulsion has been used on small areas of

the scalp at double the strength recommended. Some migration has

been caused, but many of the mites seem to have been killed in situ.

As it is probably unwise to use benzyl benzoate at double strength

except on very limited areas, and as it fails to effect complete

cure even when so used, this drug cannot be relied upon to control

the mite under consideration.

Tetraethylthiuram monosulphide. Another remedy much used, and with

good success according to the literature on the subject, against

human and animal scabies. Used as an alcoholic solution as

recommended, it has not proved as useful in the treatment of our

mite as have several other substances. It is stated to give

excellent control against Sarcoptes and Notoedres, but it seems not

to be the answer when used against Dermatophagoides.

Gamma isomer of hexachlorocyclohexane. This was used in the form of

an ointment sold under the commercial name of KWELL. Ticks and mites

are reported to be killed readily by this substance, but not so the

mite Dermatophagoides. It was left on the scalp for several days

before removal with a shampoo, and almost immediately thereafter the

mites could be felt moving about in their accustomed places.

40% aqueous hypo (sodium hyposulfite). This was allowed to dry on

the scalp, and was followed by a second application, which was also

allowed to dry. Sometimes hypo was used alone, or again was followed

by 5% HCl after the second application was thoroughly dry. Both

methods often brought relief for several days, even for a week or

more. But again the ova were evidently not destroyed. Although this

treatment has been repeated many times during the past four years,

the mites are still with us. However, it did give temporary relief,

and caused only a moderate amount of migration on the part of the

mites.

Considering the above list of chemicals, many of which are purported

to eradicate several species of mites commonly infesting man and

domestic animals, it would seem that the mite presently under

consideration is much more difficult to deal with than are such

other genera as Sarcoptes, Notoedres, Psorptes and Chorioptes.

Whether or not this is due to an inherent ability of

Dermatophagoides to withstand strong chemicals or whether, as it

seems more likely, this mite inhabits the dermis and is therefore

less subject to contact with chemicals which are employed against

it, we cannot say. At any rate, we have first-hand information that

this mite is not easily eradicated.

Capturing the Mite.

This was a tedious process, and the number of mites actually

captured is surprisingly low. This does not mean, to me at least,

that there were not many more mites present at any given time, which

could not be captured by any method employed.

My first attempt at locating the causative agent by examining

sloughed-off epidermis and incrustations from infested areas, after

treating these with KOH, was completely negative. Hence it followed

that similar material which was collected from my scalp and body and

sent away to two different parasitologists for examination also

yielded negative results. Both of the parasitologists were

interested in the case, and anxious to help if possible, but they

were located many miles away from the individual who had the

infestation.

During the period of the acute symptoms, my eyes were so badly

swollen that it would have been impossible for me to recognize a

mite had I been able to capture it. Furthermore, during that summer

I did not have a micrscope at my disposal. A few months after the

acute symptoms had subsided, however, I captured two very small

Hymenoptera which had been felt crawling about on the scalp. These

have been identified by Mr. C. F. W. Muesebeck, Chief of the

Division of Insect Identification Bureau of Entomology and Plant

Quarantine, in Washington, as members of the Trichogrammatidae, know

to be egg parasites. There will never be any certainty as to whether

or not these Trichogrammatidae bore any relationship to the mite

infestation, but of course there is always at least a possibility

that they were parasitic upon the ova of Dermatophagoides. The

technic, if one may call it that, of their capture was the same as

that which was soon successful in the capture of the first mite

found. It consisted of holding a bit of sterilized cotton, dipped in

lysol solution, firmly in place for several minutes directly over a

spot where a mite or some other arthropod could be felt moving

about. Success by this method was never very great, but at least it

was thus that most of the few mites taken directly from the scalp

have been captured. If successful, the mite still alive and moving

sluggishly, would be found adhering to the cotton when the latter

was removed from the scalp.

A rather amazing number of other arthropods have likewise been

captured from the scalp in the same fashion. Among these were:

several Hymenoptera of a considerably larger size than the

Trichogrammatidae; an oribatid mite; small portions of the skeleton

of an unknown arthropod bearing feathered hairs similar to those of

a trombiculid mite; what appears to be the cast skin of a small

spider; an apparent jassid; and of course, many small gnats and

other Diptera, among these being the psychodids and ceratopogonids.

Pollen of various sorts was also found commonly. Perhaps a study of

the flora and fauna of the human scalp in summer might be

interesting.

A modification of the method of capture indicated above also yielded

several mites of Dermatophagoides. Immediately following a shampoo,

especially when the mercuric iodide soap had been employed for that

purpose, mites could be felt moving and scratching at various places

on the scalp. Sometimes, following such activity, there would occur

a sharp pin-prick-like sensation in a different spot than the

original one, and the appearance at that spot of one of the

customary itching red papules which often increased in size later.

This I interpret to mean that the mite, disturbed but not killed by

the substance used in the shampoo, had come up from its " den " in the

dermis, and when on the surface of the skin had moved to a new

location, when again it burrowed in, perhaps using a hair follicle

as its point of entrance. If now the saturated cotton was applied

before the second burrowing-in took place, there was a good chance

of capturing the mite.

Another method of capture that has been met with greater success is

as follows. After treatment of the scalp or face with sulphur or

indeed with almost any of the chemicals listed as being of value,

mites could sometimes be found the following morning on the pillow

of the individual using this treatment. These mites, collected by

means of a bit of cotton moistened with water, were usually dead

when taken, but recently several live, active impregnated females

have been captured in this manner.

At one time only did I succeed in " digging out " a mite from my own

scalp, by means of an exploratory fingernail applied to the area

beneath an incrustation, the latter having been forcibly removed.

The mites had been felt moving about under this incrustation. When

thus captured, the mite was quite alive and healthy, and waved its

legs lustily as it was being examined under the microscope.

It is perhaps worthy of note that even a small mite, when moving

about actively in or on one's scalp feels " as large as a cat. " A

peculiar sensation as of pressure sometimes occurs synchronously

with the activities of a mite which has been annoyed by treatment

with some chemical. This has been especially noticeable after the

use of sulphur ointment. Then there is another peculiar sensation

sometimes felt: a " streaming " activity, as though many mites,

perhaps small ones, were leaving some common center, due to the use

on the scalp of some chemical distasteful to them, and " fanning out "

in various directions from this center. In fact, some mites may

later be located in red papules that had not been there before, on

face, neck or shoulders, following such a streaming. I venture to

preduct that if any dermatologist should become the host of this

mite, he would not diagnose his case as " Just imagination. "

Possible Source of the Infestation.

The source of the infestation is completely unknown. Two possible

sources are: (1) two pet cats of the household, the last one of

which died at least ten years ago; these cats suffered from what we

called " mange " for which ailment we treated them, with some degree

of success, with Seargant's Mange Cure; and (2) a neighbor's doc,

which for years suffered from some sever skin infection which

several good veterinarians tried in vain to bring under control, so

that the dog had finally to be destroyed. It is possible that our

cats acquired their infestation from the dog, and that we acquired

ours from either the cats or the dog.

At the time of the most acute symptoms, in the summer of 1943, I

tended toward the belief that the infestation had been acquired, in

my case, from a woodchuck which I had used to obtain material for

some histological preparations. That the woodchuck did have

ectoparasites, I know for a certainty, as I not only removed from

its body some lice (apparently Enderleinellus marmotae) but also

some immature or nymphal Ixodes. I noted some of the latter climbing

my arm as I worked on the woodchuck, and later captured one nymphal

Ixodes, probably cookei, from my own scalp. However the fact that I

had noticed itching papules in my scalp for some years previous to

this time, leads me to believe now that the mite Dermatophagoides

did not come to me from the woodchuck. This mite has been rather

recently reported from rats, but I have had no occasion to work with

rats other than to kill an occasional white rat for histological

purposes. The same mite has been reported from the skin of birds.

But I have had occasion to come in contact with birds only to pick

off a few ectoparasites from such dead specimens as may have been

brought into the laboratory, and most of this has been done since

1943.

The fact that the infestation has lasted for so many years seems to

indicate that the mite can adjust itself readily to life on or in

the human skin, and maintain itself there once it is well

established.

Taxonomic Considerations.

This mite belongs to the family Epidermoptidae, which may be easily

distinguished from its nearest ally, the family Psoroptidae, by the

fact that the females of the Epidermoptidae possess suckers on all

the tarsi, whilst females of the family Psoroptidae have long

whiplike setae on the third tarsi.

Dermatophagoides Bogdanow, 1864

Dermatophagoides Bogdanow, 1864. Bull. Soc. Imp. Nat. Moscou 37 (1):

341-348, pl. 7, figs. 1-2.--Vitzhum, 1929. Tierreich Mitteleuropas,

Acar, Bd. 3, 1f. 3,102--Sasa, 1950. Japanese Journal of Experimental

Medicine 20:519-525.

Pachylichus Canestrini, 1894. Prospetto del' Acarofauna Italiana,

fasc. 6:824-829, pl. 77, figs 1-4.--Berlese, 1897. Acari, Myriopoda,

Scorpiones, Cryptostigmata, Sacroptidae, fasc. LXXXII, no 12.--

Oudemans, 1904, Ent. Bericht. 20:190-195 (synonomy with

Dermatophagoides.)

Mealia Berlese, 1897. Acari, Myriopoda, Scorpiones, Cryptostigmata,

Sarcoptidae 1:104.--Berlese, 1898. Idem., fasc. LXXXIX, no. 10, and

XCII, no. 3 and no. 4--Canestrini and Kramer, 18999, Das Tierreich,

Demodicidae and Sarcoptidae, 137-138.--Trouessart, 1901, Bull. Soc.

Zool. France XXVI:82-84.

Viscopteres Sasa, 1947. Nisshin Igaku 34(3):167-170.

Type: Dermatophagoides scheremetewskyi Bogdanow, 1864. Bogdanow

described two forms of mites. The first of these, designated D.

scheremetewskyi, is a female, depicted in dorsal and ventral views

in figs. 1a and 1b. It occurred on the surface of the skin of humans

suffering from the itch. The mite of the second type, found on a

single occasion on a child suffering from herpes farinosus, and

designated by Bogdanow as " Acarus de l'Herpes farinosus, " is

depicted in figs. 2a and 2b. It is a male, very probably that of D.

scheremetewskyi as Bogdanow himself suggested; certainly it belongs

in the same genus as the previously described female mite. Bogdanow

compares his new genus with Dermatophagus, saying that it has " une

grande resemblance ave selui des acriens due genre Dermatophagus,

decrit en detail par Furstenberg. "

He notes two differences between Dermatophagoides and Dermatophagus:

(1) the conformation of two lyre-shaped chitinous arcs near the

genital opening of the female; and (2) differences in the termini of

the third legs of the females. (Dermatophagus Furstenberg, 1861, is

a synonym of Chorioptes Gervais, according to Ewing, 1929.)

Dr. Menber, an M.D., reports on the finding of a species of

parasitic mite infesting the human skin and causing a sever

dermatitis. This mite he describes and figures, as: " Acarus

incapsulator or Sarcoptes trichogenetos (Boeking). " The mite is said

to have been found also in capsules beneath the skin of the same

patient and was thought to be related to or be the causative agent

of trichinosis, hence the specific name applied to it.

North American records are: Texas; in a house in Kentucky; from a

rat in Florida; from a house in Chester, N.H., causing an itch; and

from New York. These, combined with the European distribution,

indicate a rather widespread range and eventually the mite should be

found throughout most of the world.

Several other species have been placed in Dermatophagoides, but much

work is needed before the exact status of the various species can be

determined with certainty. Dr. Manabu Sasa, of the Institute of

Infectious Diseases, University of Tokyo, Japan (The Japanese

Journal of Experimental Medicine, vol. 20, pp. 519-525, 1950),

discuss the genus Dermatophagoides in Japan. D. saitoi (Sasa) was

taken in sputum of a patient with typical Loeffler's syndrom, D.

takeuchii was found in urine, and an undertermined species was

obtained from a patient with chronic bronchial asthma.

Generic characters. Body oval. Dorsal shield present. Prominent

transverse groove anterior to middle of body, the two hind pairs of

legs posterior to this groove. Sexual dimorphism evident, especially

noticeable in legs of male; however, all legs in both sexes are well

developed. Posterior end of body more or less rounded, not lobed in

either sex. A pair of copulatory suckers present on anal plate of

male. Genital openings of female between third coxae; surrounded by

a crescentic anterior and two curved lateral sclerotized supports.

Corresponding opening of male somewhat more posterior, lying between

fourth coxae. Penis short, conical. Epimera of first legs not

united. All tarsi in both sexes with short terminal stalks

(peduncles) which bear cup-shaped suckers. Claws, where present,

small and not easily discernible. Two pairs of long, strong

posterior setae, the outer pair longer. One pair of vertical setae,

also long and strong, arise from anterior portion of dorsal shield.

Chelicerae powerful, terminating in paired chelate cutting surfaces

which are dentate on the inner margins. Legs I and II directed

forward; legs III and IV directed backward.

Dermatophagoides scheremetewskyi Bogdanow

Dermatophagoides scheremetewsky Bogdanow, 1864. Bull. Soc. Imp. Nat.

Moscou 37(1):341-348.

Mealia pteronyssina Berlese, 1897. Acari, Myripoda, Scorpiones,

Cryptostigmata, Sarcoptida 1:104.

Acarus incapsulator Menger, 1896. Texas Medical News, San ,

Texas, Sept. 24:1-20 (attributed to Boeking).

Sarcoptes, trichogenetos Menger, 1896. Texas Medical News, San

, Texas, Sept. 25:1-20 (attributed to Boeking).

Eleven females and nine males, all adults, were available for study.

Three of the females, taken alive, were observed before being

killed. On larva and two nymphs are also present in the available

material. Mites were mounted (a) in clarite, after clearing in

xylol, or ( in modified Berlese's medium, usually direct from 35%

alcohol. Some mites were cleared in KOH previous to mounting;

others, including most of those mounted by the second method, did

not undergo such preliminary treatment. Male mites are almost

transparent, but female mites, unless cleared, show well only such

structures as are on the surface which is uppermost. Certain

morphological features are seen more clearly in mites mounted by the

first method; others, by the second.

Size. Female: 10 specimens measured. Average length, 355.2 u, from

tips of mouthparts to tip of abdomen; average width 196.8u. Longest,

400u; shortest 320u; widest 240u; narrowest 160u. Male: 8 specimens

measured. Average length 296u; av width 180u. Longest: 352u;

shortest 256u; widest 208U; narrowest, 128u.

Mouthparts. See Plate III, figs. 15, 16, 17, 18 and 19. These are

quite complicated, heavily sclerotized, and interpretation of some

of th parts is difficult. Two large chelicerae are present, each

bearing distally a pair of cutting surfaces, the inner margins of

which are dentate or serrate, as indicated in figures 15, 16, 17 and

18. From ventral view, two large triangular or conical structures

are seen; from beneath these, the cutting surfaces are visible.

Perhaps these represent a bilobed hypostome or rostrum. These

structures are shown in the ventral views of male and female mites,

Pl. I, figs. 3 and 4. Viewed from above, a very similar pair of

triangular structures lying directly beneath the basis capituli

almost obscures the cutting surfaces, which can be seen only by

focussing downward. These are perhaps the basal portions of the

chelicerae, on which the cutting surfaces are bone. It appears,

then, that there are two sets of sclerotized, conical sturcutres, on

pair dorsal, the other ventral, with the cutting surfaces between

them, and attached to the uppermost pair of sclerotized cones. A

pair of well-developed palps is present, on palp lying on each side

of the conical structures. Each is four-segmented, if the basal

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One mite was kept alive for two days, at the end of which period it

was as lusty and active as when first caught. Immersion in water, in

which the cotton was kept moist, did not seem to disturb the mite.

Occasionally a mite would leave the cotton and try to crawl about on

the floor of the watch glass, but made little progress.

One mite was killed in warm, not hot, water in which it died very

quickly. A second was immersed in lysol solution of the strength

used for treatment of the scalp. For 30 seconds it swam actively,

then became quiescent. At 45 seconds, no movement could be detected.

It is thus evident that the mites are susceptible and easily killed,

if the killing substance can be brought into contact with them. But

when in or under the epidermis, they are well protected.

Opportunity is taken here to mention a similar situation in which

another mite, Bdellonyssus sylviarum (C. & F.), family Laelaptidae

(Dermanyssinae) was the causative agent. Several years ago a Mrs. X

wrote me in regard to a difficulty which she and other members of

her family had been experiencing. They had been suffering

considerably from the attacks of an unknown " something " which was

present on their scalps and bodies, and which they had been unable

to eradicated. Mrs. X, on the advice of her physician, had consulted

a dermatologist, who told her she was merely suffering from

a " phobia " and to go home and forget it. Two days later, Mrs. X was

fortunate enough to capture two dead mites that fell from her scalp.

These she took to the dermatologist, who now became interested in

her case, and prescribed some lotion as a treatment. Meantime he

sent the two mites off for identification, and in due time they came

to me. I believed them to be Bdellonyssus sylviarum, but sent them

to Dr. W. Baker for confirmation. He concurred in the above

identification.

I have had some further correspondence with Mrs. X on this subject.

The last letter, written several months ago, indicated that she was

still suffering from the effects of the parasites, and that nothing

prescribed by doctor or dermatologist had been of permanent value in

controlling her trouble. On the theory that English sparrows nesting

under the eaves might have brought the mites into their home, the

family had had the entire house fumigated, repainted and repapered

and still Mrs. X suffered from the mites. The other members of her

family had meantime recovered from their unpleasant experience with

the arthropods.

Here, then, is another instance in which humans, attacked by mites

other than Sarcoptes, have received scant attention from the medical

profession. Had Mrs. X not been fortunate enough to capture the two

mites, she might really have come to believe that she did have

a " phobia, " whatever that expression may be taken to mean. And even

with the causative agent at hand, and identified, the dermatologist

was unable to treat the infestation successfully.

A certain parasitologist, in conversation on the subject of mites,

has told me that he has had several experiences similar to the

above, in which persons fairly frantic from the attacks of some

unknown creature had been unable to obtain aid from their doctors,

and had written him or come to him for help.

What, on the other hand, could a medical adviser or dermatologist

prescribe, in the present state of our lack of knowledge, in such a

case? So little is known of the activity and behavior of many mites

that may occasionally infest man, and so little also as to the

effective methods of treatment. This is, I believe, a subject which

is in great need of further investigation. I suggest that the

medical profession might do well to take the lead in such a study.

The mite dermatophagoides scheremetewskyi Bogdanow, a member of the

family Epidermoptidae, is herewith reported as attacking humans,

infesting the scalp as well as other parts of the body. Its behavior

is not similar to that of such mites as Sarcoptes. It is believed

that the mites burrow down into the dermis, in which they make their

runways, and that they occasionally come to the surface from these

runways. In general, movements of the mites from place to place are

believed to occur within the shelter of these runways.

To date, no treatment employed against the mite has been completely

effective, in the sense of killing the ova as well as the adult

mites. Nor has repeated re-application of any of the substances

used, proved effective in eradication. Many different substances

known to be highly effective against Sarcoptes and Notoedres have

been employed as scabicides over the past seven years, in attempts

to bring about control or eradication of the mites. Of these, the

old standby, sulphur ointment 15%, is the one to which we return

again and again, after other substances have failed. Yet it, too,

has been unable to eradicate these arthropods. Three compounds which

have been most recently used, benzyl salicylate, 2-

phenylcyclohexanol, and benzyl benzoate used at double strength, may

perhaps be the answer to our problem, but it is still too soon to

know. Certain other substances known to be effective against

sarcoptic scabies have proved of little value in the treatment of

Dermatophagoides. Among these are tetraethylthiurum monosulfide, and

benzyl benzoate used at the usual strength.

The infestations here reported have lasted ofver a period of at

least seven years, and have occurred on three adult members of the

same family. The source from which the infestation was originally

obtained is unknown. If, as we surmise, infested cats or a dog

suffering from mange may have been the source or sources, there has

been no chance for reinfestation for some years, as these animals

have long since died. But there is no certainty that the " mange "

from which they suffered was produced by the same causative agent as

that which has infested us. It seems probable that the human

infestation has lasted for this period of time due to continued self-

reinfection of each individual concerned, since the ova are

apparently never destroyed by any treatment we have employed. It

should be noted that the mites seem to thrive on cleanliness, if

weekly, sometimes semi-weekly, shampoos during the entire period of

time can be used as a criterion. The mites, be it recalled, occur

principally on the scalp.

It is to be hoped that members of the medical profession may soon

come to realize that it is possible for humans to be infested with

mites other than Sarcoptes, give the patient the benefit of the

doubt and try to determine the real cause of the ailment. It is not

too easy for a person infested with said mites to make a diagnosis

himself, nor to prescribe treatment if he is fortunate enough to

locate the causative agent. The medical adviser and the

dermatologist, on the other hand, are in a position to add much

valuable information in regard to the habits and activities of this

and other human-infesting mites, as well as to determine methods of

control or eradication, if only they are willing to do so. We can

but echo Bogdanow, when he states: " Il serait a desirer que les

observations prochains de M. Scheremetewsky et des autres

dermatologues nous donnent plus des details sure les acaricides,

parasites de la surface de la peau de l'homme. "

Had it not been that the writer of this article was (1) unwilling to

accept the dermatologist's verdict of " Just imagination " ;(2) had

sufficient knowledge of parasitology and access to enough literature

on this subject so that she was able to proceed " on her own " in

quest of the invading organisms; and (3) knew how to preserve and

mount the mites when found, this mite would in all probability not

have been located, and the difficulties experienced would never have

been attributed to their real cause. It is quite possible that the

mite Dermatophagoides infests humans more often than anyone has

known, but that its attacks are usually of a minor order, so that

the itching and other annoyances caused by its presence may be

attributed by the human host to (1) " imagination, " as the doctors

would have us believe; (2) " summer heat, " since the mites are most

active during hot weather; or perhaps (3) " dandruff. " A wide-open

field exists for anyone enterprising enough to do some real

investigation on this subject.

The presence of the mite Bdellonyssus sylvarium as a causative agent

of dermatitis in the human scalp and on the human body is likewise

reported. At last reports, the unfortunate host of this mite was

still suffering from its depredations. In this case, the diagnosis

has been: " Just a phobia. " Here is another field in which to date

there has been no competition in the matter of studying the mite as

an occasional human parasite.