Clive Anderson - AT THE DERMATOLOGISTTINEA VERSICOLOR or more commonly 'liver spots' is a common skin infection due to an overgrowth of yeast on the skin. The yeast is known as Mallassezia furfur and is normally present on the skin of most persons. Anyone can develop a yeast infection of the skin.
The yeast normally lives in the pores of the skin and thrives in oily areas such as the neck, upper chest and back. Consequently, the infection affects the skin of the chest, back and shoulders most commonly. The face may also be affected. The condition is not considered contagious, as the causative organism is present on all skins. In most persons, the presence of the yeast on the skin does not cause any visible changes. In some individuals, the yeast grows more actively on the skin and causes a rash. The reasons why the yeast affects the skin of some persons while remaining as normal flora in others is not known.
Tinea versicolor usually produces few symptoms. Only rarely is there itching. The yeast however prevents the process of pigmentation. This results in patches of skin with less pigment than the surrounding areas of normal skin. These patches appear as pale or white spots; sometimes the spots may be brown coloured. These patches tan less than the surrounding normal skin and so become more visible with sun exposure. Often fine scaling is visible over the spots. During the hot summer months the frequency of this skin infection increases.
SKIN SCALES
Tinea versicolor occurs worldwide, with a prevalence of over 50 per cent in hot countries and only one per cent in colder climes like Sweden. Although the skin colour changes are more easily seen in dark-skinned individuals, the condition occurs in all races. The disease is most common in the age groups 15-24, occurring rarely before puberty and after age 65 years.
Although the light and dark-coloured spots can resemble other skin diseases, a dermatologist easily makes the correct diagnosis. The doctor may do a skin scraping and examine the scales under a microscope for the presence of the yeast. Under a special light in the dermatologist's office, the yeast fluoresces a yellow green colour. Tinea versicolor may present in three forms:
The most common form is a light-coloured scaly spot over the chest and back. The spots may coalesce into larger patches.
The second form occurs less frequently appearing on the face and arms.
The third form is when the yeast affects the hair follicles resulting in fine red bumps on the back and chest.
TREATMENT
Tinea versicolor is treated with topical or oral medications. The topical medications include shampoos, creams or lotions applied directly to the skin. Oral therapy is often preferred by patients because of its convenience and perceived greater efficacy. Because of interactions with other medications and possible side effects, oral therapy has to be carefully supervised. Diet has so far not proved successful in affecting the course of the condition or the likelihood of recurrences. It is important to remember that while the yeast is easily eradicated from the skin the colour changes take weeks to return to normal. Recurrences are common as the yeast quickly recolonises the skin.
Dr. Clive Anderson
is a dermatologist and venereologist; email: yourhealth@gleanerjm.com.
