Hello. Thank you for writing to us I suggest a possibility of Pityriasis Versicolor. P. Versicolor is a superficial fungal infection caused by a yeast, Malassezia furfur. This yeast feeds on the oil produced by sebaceous glands. In hot and humid weather conditions this yeast may proliferate and form reddish brown, scaly lesions on sebaceous gland rich areas i.e chest, shoulder, back and proximal extremities. The diagnosis can be confirmed by KOH scraping and visualizing it under the microscope for fungal elements. P. versicolor lesions are asymptomatic. Treatment is either with Oral antifungals like fluconazole Or with Topical antifungals like ketoconazole. I usually suggest my patients to use a ketoconazole based lotion over the whole affected area once daily during shower, lather it well and left over for 5 minutes. This exercise should be repeated once daily for 5 days. Lesions resolve with post-inflammatory hypopigmentation which resolves gradually over the next 2-4 weeks. I suggest you to visit a dermatologist for a confirmatory diagnosis as well as appropriate treatment. Regards