Underarm chicken skin is mostly considered to be acanthosis nigricans, and the methods of elimination include etiologic treatment, medication, and physical therapy. Acanthosis nigricans is a kind of skin disease characterized by symmetrical distribution of hyperpigmentation and velvety thickening, which mostly occurs in the folds of the skin, manifesting itself as deepening of the skin color, which is light grey, light brown or blackish brown, with a dry and rough surface. 1. Etiological treatment: obese patients can be improved through a healthy diet and regular exercise; for those with excessive androgens, oral sex hormone therapy such as methyltestosterone; hypothyroidism can be treated with thyroid hormone. 2. Drug therapy: if the cause is unknown, local topical keratolytic agent can be used, such as 0.05% to 0.1% retinoic acid ointment, 3% to 5% salicylic acid ointment, 10% to 20% urea cream or 12% ammonium lactate lotion, etc., which can soften or dissolve the keratin and improve the symptoms. 3. Physical therapy:When the effect of medication is not good, continuous pulsed CO₂ laser therapy can be applied locally. It is recommended that patients use medication in strict compliance with the doctor’s instructions, not blindly self-medication, to avoid adverse reactions and delay the condition.