Pityriasis versicolor

Pityriasis versicolor (also called tinea versicolor) is a common superficial skin infection caused by a yeast that naturally lives on our skin. Under certain conditions, the yeast overgrows and produces discoloured patches — usually on the chest, back, shoulders, and upper arms. It's especially common in hot, humid climates, which is most of India for large parts of the year, and it tends to recur.

Symptoms

• Patches of skin that are lighter (hypopigmented) or darker (hyperpigmented) than surrounding skin
• Sometimes pink or reddish-brown patches
• A fine scale on the patches — often more visible after scratching
• Mild itching (sometimes)
• Usually more noticeable after sun exposure, when surrounding skin tans but affected skin doesn't

The condition is not dangerous and not contagious in the usual sense — the yeast is already on everyone's skin. It can be cosmetically distressing, especially on visible areas.

Risk factors

• Hot, humid weather
• Oily skin
• Heavy sweating
• Teenagers and young adults (increased sebum production)
• Weakened immunity
• Hormonal changes (pregnancy, some medications)

Diagnosis

Usually a clinical diagnosis — a dermatologist recognises the appearance. A Wood's lamp (special UV lamp) may show characteristic fluorescence. A skin scraping can confirm if needed.

Treatment

• Topical antifungals — antifungal shampoos or creams applied to affected skin for a week or more
• Oral antifungals — for widespread or resistant cases, your doctor may prescribe a short course
• Treatment usually works within weeks, but the colour changes can take months to fully resolve even after the infection is cleared

Preventing recurrence

Recurrences are very common — often in summer or during hot weather:

• Bathe daily after sweating
• Dry skin well, especially in folds and on the back
• Wear loose cotton clothing
• Periodic application of ketoconazole shampoo (say, once a month) before the hot season can prevent flare-ups
• Don't share towels or clothing during active infection