Rafique Soomal, Dihowm Hanan, Parveen Sanober, Jakoby Michael
Internal Medicine, Southern Illinois University School of Medicine, Springfield, USA.
Internal Medicine/Endocrinlogy, Southern Illinois University School of Medicine, Springfield, USA.
Cureus. 2025 May 3;17(5):e83424. doi: 10.7759/cureus.83424. eCollection 2025 May.
Acanthosis nigricans (AN) is a hyperkeratotic dermatosis characterized by hyperpigmented, velvety skin plaques, most commonly found on intertriginous sites such as the dorsal cervical region and axillae, though it can potentially occur on any skin surface. AN usually presents as a manifestation of systemic disorders associated with high-grade insulin resistance, such as obesity, metabolic syndrome, or type 2 diabetes mellitus (DM2). However, AN occurring at sites of subcutaneous insulin injections is rare. We present a case of AN developing at sites of repetitive, high-dose insulin administration on the anterior abdomen. A 70-year-old male with DM2 was referred for evaluation of a "rash" at his insulin injection sites. He was prescribed a cumulative daily dose of 680 units of U-500 insulin and 80 units of insulin glargine U-300, all of which he reported injecting into the periumbilical area. Examination revealed a discrete, hyperpigmented, verrucous plaque surrounding the umbilicus, consistent with AN, with no other areas of affected skin. Histologic findings from a biopsy of the lesion showed papillomatosis and hyperkeratosis, features characteristic of AN. The patient was advised to avoid injecting insulin into the affected area and to rotate injection sites frequently. Modest improvement in AN was observed over the next three months, with more significant improvement during the subsequent six months following treatment with 0.1% retinoic acid cream.
黑棘皮病（AN）是一种角化过度性皮肤病，其特征为色素沉着、天鹅绒样皮肤斑块，最常见于颈部背侧和腋窝等皮肤褶皱部位，不过也可能出现在任何皮肤表面。AN通常表现为与高度胰岛素抵抗相关的全身性疾病的一种表现，如肥胖、代谢综合征或2型糖尿病（DM2）。然而，发生在皮下胰岛素注射部位的AN较为罕见。我们报告一例在前腹部重复高剂量胰岛素注射部位发生的AN病例。一名患有DM2的70岁男性因胰岛素注射部位出现“皮疹”前来就诊。他每天使用的胰岛素累计剂量为680单位U-500胰岛素和80单位甘精胰岛素U-300，他称所有这些胰岛素均注射在脐周区域。检查发现脐周有一个孤立的、色素沉着的疣状斑块，符合AN表现，无其他皮肤受累区域。病变活检的组织学结果显示乳头瘤病和角化过度，这是AN的特征性表现。建议患者避免在受累区域注射胰岛素，并经常更换注射部位。在接下来的三个月中观察到AN有适度改善，在随后使用0.1%维甲酸乳膏治疗的六个月中改善更为显著。
