It is a rare disease of unknown cause, and its relationship with verrucous nevus, benign type of acanthosis nigricans and ichthyosis is still controversial, most of them are considered as an independent disease. Clinically, the disease is divided into three types: 1, caused by epidermal nevus extending to the nipple; 2, accompanied by ichthyosis, which can occur bilaterally and symmetrically, and can affect both men and women; 3, nevus-like type, not accompanied by ichthyosis or epidermal nevus, commonly seen in women aged 20-30, with bilateral areola and nipple symmetrical skin pigmentation deepening to dark brown, areola expansion, clear border, local infiltration, epidermal hypertrophy, roughness in the form of warty protruding The dark brown patches, deepening and widening of the sulcus, and part of the deepening sulcus mixed with each other to form a wider and deeper linear deep sulcus, dividing the areola rash into several small pieces. Patients are often not obese, have no conscious symptoms of lesions, are generally unaffected by health, have no family history, and are not associated with endocrine disease or malignancy. Histopathological examination shows hyperkeratosis of the epidermis, but also follicular keratosis, regular hypertrophy of the spiny cells, papillomatous hyperplasia, prolonged and fused dermal protrusions, increased pigmentation of the basal cells, edema of the dermal papillae, dilated superficial capillaries, and focal inflammatory cell infiltration around the vessels. There is no specific treatment for this disease. Topical corticosteroids or keratolytic agents are available and are not effective. It is a rare disease and the relationship with verrucous nevus, benign form of acanthosis nigricans and ichthyosis is controversial, and most currently consider it to be an independent disease. The cause of papillary areolar hyperkeratosis is unknown, with more adult-onset females having enlarged areolas with papillary or warty brown and black papillae on the surface, often with similar damage, usually symmetrically distributed, and without obvious self-conscious symptoms. Pathophysiology The epidermis is hyperkeratotic, but follicular keratosis, regular hypertrophy of spiny cells, papilloma-like hyperplasia, increased pigmentation of basal cells, edema of dermal papillae, dilated superficial capillaries, and focal inflammatory cell infiltration around blood vessels. Diagnostic tests No specific treatment is available. 0.05%-0.1% retinoic acid ointment or keratolytic exfoliator can be tried.