Hello. My Husband Has Had A Problem On And Off

Hello. my husband has had a problem on and off for over a year. It starts under his scalps. It is extreemley painful and turns into a puss filled, yellow crust, painful to the touch, large bump. he has been on all sort of medicine to try to heal it and it keeps coming back, however this time he has gotten them inside his nose, causing his nose to swell and keep leaking puss out of the nose. Please help any suggestions on what it could be?