Objectives Exogenous exposure to transdermal testosterone is often overlooked as a cause of precocious sexual development in children. Case presentation A 16-month-old male presented for a second opinion consultation before commencing treatment with bicalutamide and anastrozole for a presumptive diagnosis of familial gonadotropin-independent male-limited sexual precocity. Enlargement of the penis was first observed at four months of age. The initial evaluation showed isolated elevation of his plasma testosterone level; however, by 16 months, his testosterone level was prepubertal and no pathogenic variants in the LHC GR gene were identified. The history revealed that his grandfather, who had cared for him regularly in the first year of life, had used testosterone gel for treatment of hypogonadism. Conclusions Despite the 2009 “black box” warning issued by the United States Food and Drug Administration (FDA) regarding potential consequences of transdermal testosterone exposure to women and children, this continues to be an important cause of sexual precocity in children. Children are often subjected to unnecessary and costly evaluation before this exposure is recognized, underscoring the importance of obtaining a thorough medical, family, and social history tailored to the differential diagnosis.

中文翻译：

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未识别的透皮接触睾酮导致男童性早熟：病例报告和文献综述

目的 外源性暴露于透皮睾酮是儿童性早熟的一个原因，但经常被忽视。病例介绍 一名 16 个月大的男性在开始使用比卡鲁胺和阿那曲唑治疗之前进行了第二意见咨询，推定诊断为家族性促性腺激素非依赖性男性限制性性早熟。阴茎增大是在四个月大时首次观察到的。初步评估显示他的血浆睾酮水平单独升高；然而，到了 16 个月时，他的睾酮水平已达到青春期前的水平，并且 LHC GR 基因中没有发现致病性变异。病史显示，他的祖父在他出生第一年定期照顾他，曾使用睾酮凝胶来治疗性腺功能减退症。结论 尽管美国食品和药物管理局 (FDA) 于 2009 年发布了关于妇女和儿童经皮睾酮暴露的潜在后果的“黑匣子”警告，但这仍然是儿童性早熟的一个重要原因。在发现这种暴露之前，儿童常常要接受不必要且昂贵的评估，这强调了获得针对鉴别诊断的全面医疗、家庭和社会史的重要性。