Painful, red underarms require careful observation of skin changes in the painful area. If small blisters or blister-like breakouts grow in the red areas of the armpits, consider the possibility of herpes zoster caused by infection with the herpes virus. This condition is contagious and can be treated with oral vaxilovir hydrochloride and topical recombinant interferon alpha 2b gel or acyclovir cream. If the red underarm area is diffusely flushed and may show symptoms such as breakout and oozing, consider the possibility of inter-rub rash. The condition is related to local friction and irritation, and it is recommended to choose the use of topical application of Furfuryl Glycolate lotion or zinc oxide cream, which can effectively promote the drying of the skin and thus achieve the therapeutic effect. Until the disease is completely healed, do not sweat frequently to avoid aggravating the pain.