** Thanks for contacting HCM with your health concern 1. Since the STDs test came negative and also been evaluated by a Dermatologist thus it could either be penile yeast infection [candida balanoposthitis] or could be penile psoriasis,contact/atopic dermatitis, so get a second opinion or consult an Urologist for further evaluation and management 2. people with weak immune system [immunocompromised] have episodes of recurrent infection thus check with your blood sugar, immune system examination and HIV test as a routine, as also poor nutrition and and alcohol abuse/use can cause the same. 3. since use of cortisone [steroid ointment suppress immune system thus the rash is coming back] so lifestyle changes should be followed like: . taking the MEVY [meats,eggs,vegetables,yogurt] diet . avoid sugar and refined carbohydrates . avoid using perfumed shower gels/soaps on penis which may cause irritation,wear loose fitting cotton underwear and the penis/groin to be dried carefully so that no moisture is left for the fungus to grow . tea tree oil based anti fungal cream is best to overcome 3.