Hello. Thank you for writing to us
I suggest a possibility of a Pityriasis Versicolor, which is a superficial infection of the skin caused by a yeast,
Malassezia furfur.
The infection classically involves chest, back and shoulder area because the yeast feeds on oil secreted by sebaceous glands and since these areas are rich in sebaceous glands.
The infection usually presents as faintly brown, scaly patches on chest, and upper back.
A KOH preparation made by scraping a small amount of scale and visualized under the microscope would reveal fungal elements, classically known as "sphagetti and meat ball" appearance.
Treatment is with topical antifungals like
ketoconazole lotion which is applied at the time of bath, lathered on and left to act for 5 minutes. This is continued for 3-5 days.
Single dose of an
Oral antifungal e.g
fluconazole is also curative in this condition.
I suggest that you visit a
dermatologist for a confirmatory diagnosis as well as for the needful.
Regards