Amongst the normal flora found on the skin of the vast majority of healthy people, is a yeast called Malassezia furfur. Various factors appear to trigger this yeast to change from being non-pathogenic to being pathological, resulting in the skin disease, tinea versicolor. These factors include:
- warm, humid environment (probably the most frequent)
- genetic disposition
- immunosuppression
- malnutrition
- Cushing’s disease
It is interesting that although it is a fungal infection, tinea versicolor is not contagious. This is because the organism, Malassezia furfur, is a naturally occurring commensal on most people’s skin.
Physical Characteristics of the Skin Lesions
They present as various shaped macules with clear margins, which are either hypopigmented or hyperpigmented. These macules may coalesce resulting in irregular shapes. They have a fine silvery scale if closely examined or if the skin is stretched. The distribution of these macules is mainly on the upper back or chest. In more immunocompromised patients, the lesions may be on the face, on the extremities and in the flexures.
There may be a mild itch associated, especially when warm or sweating
After effective treatment, it is not unusual for residual discoloration to last for some months.
Distribution of Tinea Versicolor
It seems to be equally distributed across the races, although the pigmentation changes are more noticeable in darker skins. There is no difference in occurrence between males and females. In terms of age distribution, it is unusual in children. In tropical, humid climates, it is most common in 20-30 year age group. While in temperate climates, it is more frequent in the younger age group (18 + years).
Differential Diagnosis of Skin Rashes or Lesions Involving Pigment Change
Other conditions which may look similar to tinea versicolor, and need to be eliminated, include:
Treatment of Tinea Versicolor
There are different options of treatment available. One should always consult one's doctor for confirmation of the diagnosis before initiating treatment, and to discuss which treatment option would be the best in a particular situation.
a) Topical Agents:
These are an effective means of treating the problem, and several of them have the advantage of being available over the counter. They include certain of the antidandruff shampoos, e.g. selenium sulfide (Selsun Blue Shampoo). These are safe and easy to use, but for some people they can cause irritation to their skins.
There are other more specific antifungal creams and lotions, e.g. Clotrimazole, Econazole, Ketacoazole, Oxiconazole, Ciclopirox, Terbinafine,Butenafine.
These treatments can often be time-consuming, needing to go on for some weeks.
b) Oral / Systemic Agents:
These are very effective, and a good deal more convenient than the topical agents. The courses are generally shorter, and are obviously simpler to use.
These include: Oral Ketaconazole (in which the 10 day course – 200mg daily – has been shown to have similar effects to the single dose – 400mg stat), Fluconazole (150-300mg weekly once a week for two to four weeks), Itraconazole (200mg daily for seven days).
c) Some people are especially prone to recurrences of their tinea versicolor. In these individuals, it may be wise for them to use their treatment again as soon as the hot, humid weather begins, as this will usually be when their tinea versicolor flares up.
In review, some of the important issues to be aware of with tinea versicolor:
- Tinea versicolor is caused by a fungal infection.
- It is benign, and not contagious.
- It is effectively treatable, but may be recurrent.
- The hyper- or hypopigmentation may last some months after completion of effective treatment of the fungal infection.
References:
Burkhart, C. J., Gottwald, L. April 6 2010. Tinea Versicolor: eMedicine Dermatology. Available: eMedicine.medscape.com , "Tinea Versicolor" (13 May 2010)
Dourmishev, L. A. March 5 2010. Tinea Versicolor: eMedicine Paediatrics: General Medicine. Available: eMedicine.medscape.com. "Tinea Versicolor" (14 May 2010)
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