Underarm melanin deposition may be caused by physiological factors, neurodermatitis, hypoadrenocorticism, etc. It can be removed by exfoliating the armpits, taking medication, supplementing adrenocorticotropic hormone and other methods. 1. Physiological factors: underarms are subjected to long-term stimulation or friction resulting in local melanin precipitation, you can exfoliate the underarms to promote melanin fading, daily attention to reduce local friction, keep the local clean and clean. 2. Neurodermatitis: a chronic skin disease, may lead to joints underarm melanin precipitation, long moss, and accompanied by itching, you can take cetirizine hydrochloride tablets and other anti-allergy drugs, with vitamin B complex tablets to improve. 3. Hypoadrenocorticism: it may lead to local skin folds and melanin precipitation, you can supplement the adrenocorticotropic hormone to improve the situation of joints and axillary melanin precipitation, such as taking hydrocortisone tablets and other drugs. Specific drugs should be taken in accordance with the doctor’s instructions, it is recommended that the patient consult a doctor in a timely manner, under the guidance of the doctor’s diagnosis, targeted treatment.