Dear user, The rash you are talking about appears to be a tinea (fungal) infection. I suggest you to keep the area dry , as wet condition may further flare up the illness. Hydrocortisone cream may show initial improvement in inflammation but later on it flares up the infection. So, self medicating may be harmful. You may require to visit a dermatologist for inspection and scrapping collection to confirm a diagnosis and thereafter you may be prescribed anti-fungal medicines accordingly. With medicines these lesion may be cure within two/three week but medicines should be continued for next few weeks to prevent recurrence. Hope it answers your query. I wish you all the best.