Can you elaborate on the appearance of the skin lesion? Diagnosis of a fungal infection
would be through analysis of the skin
scrapings under the microscope. It would be best to have it evaluated by a dermatologist to rule out other causes. Treatment of hyperpigmentation may include hydroquinone, kojic acid, azelaic acid, ascorbic acid, tretinoin, topical glucocorticoids, and licorice extract.
Take care and keep us posted.