Coexistence of two types of clinical lesions in childhood-onset mastocytosis.

The vast majority of mastocytosis appear in childhood, urticaria pigmentosa (UP) and mastocytomas being the most common types. Terms such as "xanthelasmoid mastocytosis", "pseudoxanthomatous mastocytosis" or "nodular mastocytosis" have been introduced in the literature to describe the presence of yellowish papular or nodular lesions. We describe two children with cutaneous mastocytosis showing yellowish lesions in combination with other skin lesions. A 10-year-old girl presented with asymptomatic lesions in her vulva at birth, and developed brownish macules on her trunk years after. An eight-year-old boy presented with multiple yellowish papular lesions on his trunk, neck and limbs coexisting with a few clinically anetodermic lesions. No systemic involvement was found and the skin biopsy confirmed a cutaneous mastocytosis in both cases. The two patients are currently asymptomatic and are being periodically followed up. Mastocytoses may show a variety of clinical lesions, sometimes leading to misdiagnosis. Although there are previous reports, involvement of the mucosae and secondary anetoderma are not common findings in cutaneous mastocytoses. We consider that cutaneous manifestations of mastocytoses compose a clinical spectrum, thus explaining the coexistence of different clinical lesions and the development of uncommon presentations.