Itchy bumps and rashes on the buttocks consider itchy rash, contact dermatitis, etc. If the skin is not ulcerated, glucocorticoid creams or glyburide lotions can be applied. In severe cases, oral antihistamines, glucocorticoids and immunosuppressants can be taken. For obvious skin ulcers with fluid exudation a boric acid solution wet compress or zinc oxide oil can be applied. Add topical antibiotic ointment if there is infection.