Underarm peeling may be related to psoriasis, seborrheic dermatitis, pityriasis rosea and other causes. 1. Psoriasis: it is an immune disease, which is mainly manifested as reddish skin patches and plaques covered with silvery-white scales, and may occur in the underarm area. 2. Seborrheic dermatitis: it occurs in the parts of the body with strong sebum secretion, such as the head, face, armpits and other parts. Itchiness, erythema and peeling of skin are usually present. 3. pityriasis rosea: the typical symptom is that the skin has rose-colored patches and papules with fine scales. It is recommended that people with underarm peeling go to the hospital in time to clarify the cause of the disease and standardize the treatment under the guidance of the doctor to avoid delaying the condition.