Redness, swelling and pain in the armpits may be caused by folliculitis, intertrigo, herpes zoster, lymphadenitis, etc. Doctors will decide on the treatment according to the patient’s specific situation. 1. Folliculitis: underarm is the high incidence area of folliculitis. Inflammatory reactions such as redness, swelling and pain in the affected area can be treated with topical mupirocin ointment, erythromycin ointment and antibiotics such as amoxicillin and cefaclor under the guidance of a doctor. If there is abscess formation, it can be incised and drained, with regular medication changes. 2. Interfluvial rash: Interfluvial rash refers to superficial inflammation of the skin folds, which may be caused by localized moisture, sweat impregnation, bacterial infection, and so on. It is commonly found in the armpits and other parts of the body, and patients may feel pain, itching and burning sensation. The patient may feel pain, itching, burning sensation, etc. It can be treated with topical isacridine, zinc oxide oil, boric acid solution, etc. as prescribed by the doctor. 3. Herpes zoster: Herpes zoster is the skin damage caused by the reactivation of varicella zoster virus latent in the body. Herpes zoster can attack the armpits, resulting in red, swollen and painful skin. Patients can be treated with medications such as acyclovir, methylcobalamin, and phosphonate by the doctor. 4. Acute lymphadenitis in the armpit can also lead to redness, swelling and pain, which needs to be treated with antibiotics such as amoxicillin and cefaclor. Redness, swelling and pain in the armpits may be caused by other diseases, so you should consult the doctor in time, complete the examination, and follow the doctor’s instructions for treatment after a clear diagnosis.