Pityrosporum Folliculitis

[Guest guest]

Marjorie, you wrote:

" Typically, PF in healthy persons occur after extensive use with

antibiotics, not just a few weeks, unless there is an underlying

predisposition to fungal infections. "

Isn't Pityrosporum folliculitis caused by the same yeast that is thought may

be implicated in seborrhoeic dermatitis - pityrosporum ovale? In the case

of seb. derm. I understand the theory is that pityrosporum ovale (a common

lipophilic yeast which is normally present in the follicles in all people)

either becomes prolific or the person becomes more sensitive to it.

You go on to say

" It's not that competent doctors overlook PF, but that to my knowledge

it's not appropriate to consider it early on in an otherwise healthy

person. "

I have read that in the case of seborrhoeic dermatitis, although it can

occur more frequently in those that have compromised immunity, lots of

people who have it are otherwise healthy and I know a lot of us with rosacea

also have concomitant seborrhoeic dermatitis. If one accepts the theory

that seborrhoeic dermatitis is caused by a proliferation of p. ovale, then

what is the difference between p. folliculitis and seborrhoeic dermatitis?

If the p. ovale lives in the follicles normally and folliculitis simply

means inflammation of the follicles, isn't this the same as seborrhoeic

dermatitis?

I am curious about this because, just like maxigee who wrote, itching can

rate highly in my case of diagnosed rosacea/seb.derm and I also did not do

at all well with antibiotics. My skin is sensitive +++ to the point that I

react to all topicals to a greater or lesser extent and ketoconazole cream

causes real problems. I have often thought if I could successfully treat

the seb. derm. by decreasing the numbers of p. ovale, my condition would

improve immensely but have been hesitant about taking any oral antifungal

medications because I wondered if they would only act for a short while and

then whatever was causing the p. ovale to be prolific, if still present,

would eventually cause it to return. Repeated short courses of oral

antifungals I assume would come with their own problems?

Hazel

[Guest guest]

> Isn't Pityrosporum folliculitis caused by the same yeast that is

> thought may be implicated in seborrhoeic dermatitis - pityrosporum

> ovale? In the case of seb. derm. I understand the theory is that

> pityrosporum ovale (a common lipophilic yeast which is normally

> present in the follicles in all people) either becomes prolific or

> the person becomes more sensitive to it.

Hazel, my understanding is that the classification of Pityrosporum

yeast has undergone a number of changes and since they are now

thought to be all the same organism, pityrosporum ovale, and they've

renamed it malassezia furfur. (I hate when they start changing names

on us. <g>.)

It is part of normal adult skin flora but I don't believe normally in

the follicles/glands -- I think it stays on the topmost surface of

the epidermis, the stratum corneum (Matija's favorite layer. <g>).

But malasseia is also associated with several skin diseases -- not

only SD and PF, but other conditions such as pityriasis versicolor

and some forms of atopic dermatitis. It's not that weird that one

organism in involved with different conditions in different ways, but

it is confusing.

> I have read that in the case of seborrhoeic dermatitis, although it

> can occur more frequently in those that have compromised immunity,

> lots of people who have it are otherwise healthy and I know a lot

> of us with rosacea also have concomitant seborrhoeic dermatitis.

Right, there seems to be an association between rosacea and

seborrheic dermatitis, just as each is also associated with other

skin conditions (acne, eczema, etc).

> If one accepts the theory that seborrhoeic dermatitis is caused by

> a proliferation of p. ovale, then what is the difference between p.

> folliculitis and seborrhoeic dermatitis? If the p. ovale lives in

> the follicles normally and folliculitis simply means inflammation

> of the follicles, isn't this the same as seborrhoeic dermatitis?

I believe that PF is caused by malassezia infecting the hair

follicles (sebaceous glands); the reason for the normally gentle

yeast travelling down the gland and becoming pathologic isn't known,

but there are a number of predisposing situations such as diabetes

mellitus and immunodeficiency, among many others, although many are

seemingly normal middle-aged women. Increasing attention has been

given to PF in patients on chronic antibiotics that affect skin

flora, and as a source of confusion in chronic rosacea unresponsive

to traditional therapies. To my knowledge, exposure to new

environmental hazards isn't a cause for PF, as Max suspects.

Something must be triggering PF, because we all have malassezia all

over our bodies and it typically stays on the surface, it normally

doesn't infect our follicles, but apparently in many patients the

predisposition is never found.

In contrast, I don't believe that current thinking has SD caused by

malassezia, though clearly the yeast plays some pathogenic role.

Malassezia thrives in conditions where there is increased sebum and

skin cell turnover, which describe SD. There's lots of theories and

conflicting study results, and it will be interesting to see how it

is all sorted out over the next few years. I find it intriging that

various studies have associated SD skin with high, normal, and even

low levels of malassezia compared to non-SD skin, and also that some

individuals with SD have common immunologic features. But who knows?

So the yeast isn't causative in the same sense as in PF, but is

involved in the pathophysiology of SD. I would assume contemporary

maintenance care for SD skin includes both control of abnormal sebum

production and increased skin turnover, and also control of

malassezia -- unlike for PF where treatment is only the control of

malassezia. In both PF and SD, underlying predispositions are

important to identify and correct if possible but SD, like rosacea,

has familial and immunologic associations that evoke genetics (which

I don't believe apply to PF).

I'm very much in learning mode, so please understand that the above

is my knowledge at the time of writing. I would appreciate it if

anyone who can add or clarify my knowledge to anything above. I may

not have the most current understanding.

> I am curious about this because, just like maxigee who wrote,

> itching can rate highly in my case of diagnosed rosacea/seb.derm

> and I also did not do at all well with antibiotics. My skin is

> sensitive +++ to the point that I react to all topicals to a

> greater or lesser extent and ketoconazole cream causes real

> problems. I have often thought if I could successfully treat

> the seb. derm. by decreasing the numbers of p. ovale, my condition

> would improve immensely but have been hesitant about taking any

> oral antifungal medications because I wondered if they would only

> act for a short while and then whatever was causing the p. ovale to

> be prolific, if still present, would eventually cause it to return.

> Repeated short courses of oral antifungals I assume would come with

> their own problems?

Hazel, I don't have an answer. As I said above, my understanding is

that there isn't a direct cause-effect relationship between yeast and

SD. But still, talk to your dermatologist about the role of oral

antifungals in SD -- I honestly don't know, but there may be a role

for you, perhaps to help the skin calm down enough to tolerate

topical anti-fungals. They are serious medications so it's not

something to order over the Internet but they are safely used in a

number of chronic or predisposing conditions as part of an overall

maintenance plan, so definitely don't rule them out on that account.

Either you like the letter " o " or you were educated/live under

British rule? <g>

Marjorie

Marjorie Lazoff, MD