Relevance-Diffuse cutaneous mastocytosis (DCM) is a rare clinical form of mastocytosis (0.5% of all cases of the disease). High risk of severe systemic mediator-related symptoms and anaphylaxis requires careful monitoring of children.

Material and methods.- We observed 5 children (4 boys and 1 girl) aged from 2 months to 7 years at the Moscow Scientific and Practical Center of Dermatovenereology and Cosmetology. The diagnosis in all children was confirmed by pathomorphological examination. Immunohistochemical staining with antibodies to CD117 revealed a positive reaction in the vast majority of dermal infiltrate cells. Serum tryptase level was determined by immunofluorescence on a three-dimensional porous solid phase. 

Results-In all children, mastocytosis debuted at birth. In infancy and early childhood, all children had predominantly extensive bullous lesions. Bullous lesions persisted in children up to 5 years of age. In children over 1 year of age, diffuse cutaneous infiltration with lichenification and hyperpigmentation of varying severity was predominant. At the first visit, the average tryptase level was 19.3 ng/l. During dynamic observation, a gradual increase in tryptase levels was noted in two patients during the first three years, while a decrease was observed in the rest. Multiple episodes of anaphylaxis were recorded in two children. Other systemic mediator-related symptoms (abdominal pain, diarrhea, impaired concentration and sleep, prolonged flushing, syncope) of varying severity were observed in all patients. Ultrasound signs of hepatomegaly and splenomegaly were detected in 4 children.

Conclusions-Management of patients with DCM should include dynamic observation by a pediatric dermatologist and allergist-immunologist, monitoring of the functions of internal organs and peripheral blood indices, dynamic monitoring of tryptase levels to exclude systemic mastocytosis and the prescription of anti-mediator-related and external therapy corresponding to the nature of the cutaneous pathological process.