Another Article from Dermatology Times

[Guest guest]

Hi,

This one is about skin sensitivity. From the article,it sounds like

derms don't take complaints about sensitive skin seriously (they must

have followed me to some of my own derm appointments to figure that

out)and some within dermatology want to correct the misperception or

insensitivity, if you will, on the part of derms.

Take care,

Matija

Sensitive skin valid patient problem

May 15, 2002

By: Cheryl Guttman

Dermatology Times

New Orleans - Sensitive skin is a common problem and a real one that

dermatologists need to take seriously, Albert M. Kligman, M.D.,

Ph.D., said at the annual meeting of the American Academy of

Dermatology.

" Results from studies performed in the U.S., Japan, and Europe

indicate 30 percent to 50 percent of adult women report having

primary sensitive skin characterized by a variety of objective and

subjective reactions to exogenous factors in the absence of

dermatologic disease. Some might argue such skin sensitivity is a

psychological conviction or contrived issue. However, I believe it is

a reality as demonstrated by our ability to measure it with relevant

objective tests as well as to improve or reverse it, " said Dr.

Kligman, professor of dermatology, University of Pennsylvania,

Philadelphia.

Persons with sensitive skin can be subdivided into categories based

on the type of reactions they experience. Most affected individuals

complain of neurosensory symptoms, including itching, burning,

stinging, and tightness, while clinical signs of redness, scaling,

and dryness seem less common.

" One reason why there is so much disagreement on sensitive skin is

that most people report the very subjective reactions in the absence

of visible skin changes. However, just as it is possible to rate good

wine or good scotch, we are making progress toward developing a valid

biological approach for scoring the severity of these subjective

symptoms of sensitive skin, " said Dr. Kligman.

Currently, the lactic acid stinging test offers a simple, useful, and

practical method for identifying persons with sensitive skin and

categorizing its severity. In that study, 10 percent aqueous lactic

acid is applied on the cheek near the nasal ala, which is the most

sensitive area of the face, and the evolution of stinging is

monitored over time.

" The results of this lactic acid assay are highly specific for

identifying women whose responses to a quantitative questionnaire

indicate they have sensitive skin. It turns out that people who are

very sensitive become intolerant to the lactic acid after just three

to four minutes, while the onset of stinging occurs later and peaks

at a lower level in those with moderate sensitivity, " Dr. Kligman

said.

Using the lactic acid assay, researchers have demonstrated that

emollients can be used to prevent the stinging response. The results

of those studies also show that there is a hierarchy of

protectiveness, with the benefit provided increasing with growing

hydrophobicity of the emollient agent. In addition, it has been

possible to convert stingers to nonstingers after several months of

twice daily treatment with Nivea cream.

Skin sensitivity can also be studied through application of various

other chemicals, including balsam of peru, chloroform/methanol,

histamine, and capsaicin burning, and some of the responses that

develop to those agents can be quantified using such objective

techniques as colorimetry and ultrasound.

The underlying physiological mechanism(s) for sensitive skin and

associated risk factors remain to be fully defined. Dr. Kligman said

the etiology is likely mediated through appendageal pathways, and he

noted ongoing research is leading to an understanding of features

that might predict this neurosensory problem. Recognizing that

sensitive skin is a multidimensional phenomenon, characteristics of

affected persons are being probed with a 21-item questionnaire. The

responses obtained are then analyzed using regression techniques to

identify markers for sensitive skin.

Results from studies completed so far show that most persons in the

United States with sensitive skin are phototype I. According to one

investigation, only 23 percent of individuals with that skin

phototype did not react to lactic acid while 40 percent developed a

moderate reaction and 38 percent were strongly affected. Blacks

rarely develop a stinging response to the lactic acid test, whereas

the proportion of strong stingers tends to be particularly high among

Japanese women.

Such differences among racial and ethnic groups are not unexpected,

recognizing the demographic differences in predisposition to various

skin disorders. However, they may be explained in part by differences

between populations in cosmetic practices, said Dr. Kligman.

" Japanese women have been noted in particular to have very sensitive

skin and that may be related to their habit of using strong cleansers

and toners that traumatize the facial skin and strip off the stratum

corneum, " he explained.

Evaluations of persons with sensitive skin have also identified a

number of exogenous factors that can alter the response. For example,

strong stingers become more sensitive in cold weather and are less

bothered in warm weather, heavy smoking seems to protect against

lactic acid-induced stinging, perhaps because of some

immunosuppressive effect, and ingestion of cheap red wine has been

reported to increase sensitivity.

" Considering the potential for environmental influence, it is

important that any studies of skin sensitivity control for such

factors, as well as for confounding from ethnic and racial

differences between study populations, " Dr. Kligman said. DT