Hello and welcome to healthcaremagic I would keep a possibility of pityriasis versicolor. Clinically it presents as light colored patches with fine, brawny scaling and post-inflammatory hypopigmentation. Pityriasis versicolor is a superficial fungal infection caused by Malassezia Furfur. The infection is more common in hot and humid weather conditions, which favor the growth of the fungus. A single oral dose of an oral antifungal e.g fluconazole 400 mg is curative OR Itraconazole 200 mg once daily for a week, is an alternative. If i were your treating dermatologist, i would have also asked you to apply 2% ketoconazole lotion over the whole affected while showering and leave it on for 5 minutes daily for 5 days. Post-inflammatory hypopigmentation takes some time to respond. Repigmentation can be hastened by daily sun exposure for 5-10 minutes Repeated recurrences are common and the patches may seem to persist for ever, with new patches appearing while older one resolve. Those who have repeated recurrences should use a prophylactic 3 days therapy with topical antifungals, every month i.e 2% ketoconazole lotion over the whole affected while showering and leave it on for 5 minutes daily for 5 days. Regards