Crusted Norwegian scabies in an adult with Langerhans cell histiocytosis: mishaps leading to systemic chemotherapy.

BACKGROUND Crusted Norwegian scabies is a rare hyperkeratotic variant of scabies infestation. We report herein a case of crusted scabies in a woman with underlying Langerhans cell histiocytosis (LCH). OBSERVATIONS A 49-year-old woman with LCH was hospitalized owing to marked thrombocytopenia. Her hyperkeratotic skin eruption was thought to be secondary to LCH because several years earlier, she had positive biopsy findings and had been diagnosed as having LCH. After a 1-month hospital stay, her laboratory values improved despite worsening of her skin lesions. CONCLUSION Analysis of skin scrapings confirmed the presence of scabies, and resolution was achieved with a 1-dose ivermectin treatment.