Bullous cutaneous mastocytosis, a rarely reported disease in Asian children.

Diffuse cutaneous mastocytosis, the most rare form of cutaneous mastocytosis, often manifests as bullous lesions. Although cutaneous mastocytosis should be included in a differential diagnosis for pruritic skin lesions in children, early diagnosis of the disease is not easy due to its rare occurrence. A 17-month-old boy presented with recurrent itchy bullous skin lesions. He had been treated as atopic dermatitis at other hospitals for about one year, however, he was eventually diagnosed with diffuse cutaneous mastocytosis through skin biopsy. Unlike adults, children with cutaneous mastocytosis usually improve with age and do not develop systemic mastocytosis. Therefore, early and accurate diagnosis of cutaneous mastocytosis in children is essential for appropriate care.