Ossification into the osteo‐nevus of Nanta: an interpretative insight

Abstract

ence value 0.02–0.5 9 10/l) and 18.3% (reference value 0.5–5%), respectively. Liver function showed aspartate aminotransferase (AST) 42 U/l (reference value 15–40 U/l) and total bile acid 12.9 lmol/l (reference value <10.0 lmol/l). Because of the patient’s history of taking arsenic, we checked a urinary arsenic level which was elevated at 5.776 mg/l. Histopathological analysis of a keratotic papule biopsied from the left palm showed prominent hyperkeratosis of the epidermis, mild atypia, papillomatosis, and acanthosis consistent with arsenical keratosis given a history of arsenic exposure. Chronic arsenicism causing keratosis and melanosis was diagnosed. After being hospitalized, the patient was treated with 0.1 g Dimercaprol injection once a day (5 days is a course of treatment). We conducted three courses to remove arsenic, and urinary arsenic decreased to 0.04 mg/l (reference value <0.1 mg/l), the pruritus disappeared, and hyperpigmentation was relieved remarkably. Desquamation appeared and no keratotic papule was observed on new skin. In China, the Inner Mongolia Autonomous Region is one of the regions with high arsenic content. Furthermore, Mongolian medicine is an important part of Chinese traditional medicine. Since ancient times, arsenic has been known to have medicinal value. There are many cases in which Mongolian medicine containing arsenic is used to treat patients. Khandpur has reported a case of curing arseniasis secondary skin lesion caused by epilepsy with the application of arsenic compound. In this study, the authors concluded arsenical keratosis (punctate palmoplantar keratoderma, and leucomelanoderma), seen also in our case, is the typical pathological feature of this disease. However, arsenic use may not be desirable in the face of severe side effects including widespread arsenical keratosis and melanosis as seen in our patient. Reducing arsenic storage is the standard treatment. Doctors should inform patients to avoid long-term use of arsenic and avoid iatrogenic injury.