Follicular spiny hyperkeratosis induced by sorafenib

Introduction: Follicular spiny hyperkeratosis is a rare dermatosis, usually related to multiple myeloma. Some cases associated with drug use have been reported. Case Report: A 60-year-old male patient with a history of papillary thyroid cancer started treatment with sorafenib. Ten days later, he presented with a dermatosis affecting the scalp and forehead, characterized by thick interfollicular scaling and spiny hyperkeratosis. Dermoscopy revealed tubular scaling along the hair shaft. A skin biopsy was performed, revealing a spine of compact parakeratotic material, leading to the diagnosis of follicular spiny hyperkeratosis. Conclusion: Follicular spiny hyperkeratosis can develop after exposure to sorafenib. Recognizing it allows for timely identification of causality and optimal individualized management.