It is a common infection in young individuals

Pityriasis Versicolor:

It is a common infection in young individuals
The cause is because of the presence of a yeast (fungus) called malassezia furfur.

Clinically it causes depigmented patches with fine scales on the surface (pityriasiform desquamation)

Diagnosis is straightforward and clinical. Scraping the lesions causes accentuation of scales. Microscopical examination of the scales after the scotch test provides a definitive diagnosis with an appearance of spores and hyphae called “spaghetti and meatballs.”

Treatment is easy and consists of applying antifungal creams.
However the condition tends to recur and a weekly prevention with selenium sulphide shampoo (selsun) can help.