Nineteen nail dystrophy in an atopic background responsive to dupilumab: a case report

Onychodystrophy refers to abnormal nail structure or growth arising from disorders affecting the nail unit. Published reports of pediatric nail dystrophy occurring in an atopic background remain limited. We report a 7-year-old boy whose nail abnormalities were first noted at 3 weeks of age, progressively involved 19 of the 20 fingernails and toenails in the persistent absence of any eczematous lesions. Following an inadequate response to prior conventional therapies, the nail abnormalities showed marked improvement after 8 months of dupilumab therapy. In this patient, AD-associated nail involvement was considered a possible diagnosis after exclusion of common alternative causes, and the marked response to dupilumab further strengthened this possibility. This case highlights the importance of a broad differential diagnosis for pediatric nail dystrophy and suggests that dupilumab may be a therapeutic option when an atopic contribution is clinically suspected.