<prompt> An adult presents with oval scaly hypopigmented macules over chest and back. The diagnosis is:LeprosyLupus vulgarisPityriasis versicolorLichen Planus  <response>: Pityriasis Versicolor PV Etiology:- Malassezia furfur earlier classified as Pityrosporum ovale, a commensal yeast. Pathogenesis:- PV represents a shift in the relationship between host and resident yeast flora, the yeast overgrowing in hot and humid conditions. Releases carboxylic acid which causes hypopigmentation due to reduced tanning of skin. Clinical Features:- Symptoms:- Asymptomatic. Morphology:- Hypopigmented, less frequently erythematous or hyperpigmented, so called versicolor scaly, and perifollicular macules. Frequently coalesce but invariably the perifollicular character of the lesions is retained at the periphery of the lesions. Scaling is branny and can be accentuated, if the lesion is scratched e.g., with help of a glass slide. Sites of predilection:- Upper trunk, often spreading to the neck and upper arms. Ref:- NEENA KHANNA; pg num:-291 