Hello. Thank you for writing to us I suggest a likely possibility of Pityriasis versicolor, which is a superficial fungal infection of skin caused by a yeast, malassezia furfur. The yeast feeds on oil produced by sebaceous glands and therefore the infection is common at sites like upper back and chest. The infection is more common in summers. Pityriasis versicolor presents as brown colored patches of dry, scaly skin as well as post-inflammatory hypopigmentation. Diagnosis is clinical and can also be confirmed by KOH wet preparation made by scrapping a small amount of scale from the surface skin lesions and examined under the microscope to look for fungal elements. The condition is usually asymptomatic except for the cosmetic concern. If I was the treating doctor I would have suggested an Oral antifungal e.g single dose of fluconazole is usually sufficient, Topical antifungals e.g ketoconazole lotion can also be used as body wash at bath time. It should be lathered well and allowed to act for at least 5 minutes each day, for 3 consecutive days. Other topical antifungals e.g sertaconazole lotion can also be used. I suggest that you visit a dermatologist for a confirmatory diagnosis as well as for the needful. Regards