The treatments for underarm acanthosis nigricans include etiologic treatment, medication, physical therapy, etc. Usually, it is necessary to choose the appropriate treatment according to the patient’s etiologic condition and carry out the treatment. 1. Etiological treatment: For obese patients, healthy diet and regular exercise can be used to remove acanthosis nigricans; for patients with excessive androgens, oral sex hormone therapy, such as methyltestosterone, etc.; for patients with hypothyroidism, oral thyroid hormone therapy; for patients with drug-induced acanthosis nigricans, a doctor’s assessment is needed to replace the drug or reduce the dosage. If middle-aged or elderly people suffer from this disease, it is recommended to have a comprehensive examination to exclude the possibility of tumors. 2. Medication: Generally, for those whose etiology is unknown, topical keratolytic agents can be used, such as salicylic acid, urea cream, etc. or topical hydroquinone cream to alleviate the problem of hyperpigmentation. Oral vitamin A can also be combined. 3. Physical therapy:For benign acanthosis nigricans, continuous pulsed CO₂ laser can also be taken to treat acanthosis nigricans. It is recommended that patients diagnosed, under the guidance of the doctor reasonable treatment, medication, strictly comply with the doctor’s prescription medication, not blindly self-medication.