Greetings. THIS COULD BE FUNGAL INFECTION OR INTERTRIGO. Fungal infection is quite common, especially more common in men. This is often related to humidity, tight clothing, excess sweating and accumulation of moisture. You'll need to keep the area dry, wear lose clothing. You'll need to see a dermatologist for confirmation of infection and treatment with oral antifungals and creams. If there's resistance to one particular medicine another medicine may be needed depending on your improvement. DO NOT USE OVER THE COUNTER CREAMS LIKE BETNOVATE GM OR PAN DERM OR QUADRIDERM... this will only prolong the infection. Hope this helps. DO NOT WASH WITH DDETTOL OR SAVLON THIS CAN BURN OR IRRITATE THE SKIN AND IS NOT GOING TO BE OF GREAT HELP. Caution: Make sure you see a qualified MD / DNB/ DVD dermatologist for all your skin and hair issues. Don’t be lured in by quacks. Know your treating doctor/ discourage quackery! Warm regards, Dr Govind Suresh Mittal. Bengaluru