Thanks for posting your query to HCM.
After reading your problem I can understand the stress caused by the patch. Now as per your history there is one best possibilities of your problem Known as Erythrasma
which is long standing, localized superficial infection of the skin caused by a bacteria. This occurs most commonly in axilla and also in groin region. The patch is red in the beginning, but later becoming brown. For the treatment part, there is no well set therapy as different options responds variably but it responds well to clotrimazole
But as per your query this is not responding to various cream so it is better to take oral medication such as erythromycin
under medical guidance.
The biggest problem is of relapse is a problem so you should use antiseptic soaps for long-term, and some medicated drying powders. Please don't try to apply different over the counter drugs as these may contain some irritant chemicals or even acids causing burning and soreness of skin. It is better to consult a dermatologist
who will explain and treat the condition at his best.
Hope to have given the best possible information.
With best health wishes,
Dr Sanjay K Kanodia
MD (Dermatology & STD/Venereology)