Cutaneous mastocytosis: Case report

Introduction: Mastocytosis is a group of rare diseases characterized by the infiltration and abnormal proliferation of mast cells in various tissues. The disease can have either a benign or malignant form. Symptoms result from the excessive degranulation of mast cells and the release of inflammatory mediators, which can cause hypotension, anaphylaxis, diarrhea, and other systemic symptoms. The clinical picture varies, cutaneous mastocytosis (CM) more commonly occurring in children and often spontaneously regressing, while adults are more likely to develop more aggressive forms of the disease. Case Report: We present a 22-year-old female patient with livid-brown macules that appeared four years ago and progressively spread. Initially, she was diagnosed with acute urticaria and treated with antihistamines and topical corticosteroids without improvement. Due to the persistence of symptoms, in 2024, she consulted a dermatologist, after which she was hospitalized for further diagnostics. The clinical examination indicated a positive Darier sign. Laboratory findings, bone densitometry, chest X-ray, and ultrasound of the upper abdomen were all normal. A skin lesion biopsy revealed mast cell infiltration with an immunohistochemical profile consistent with mastocytosis. Bone marrow biopsy did not indicate systemic mastocytosis. During hospitalization, no medications were prescribed, and the symptoms improved with the application of general measures. Conclusion: CM can also occur in adulthood without the development of the systemic form of the disease. The initial difficulties in recognizing and treating mastocytosis highlight the need for further education of healthcare providers, given the rarity of the disease. With proper education of patients on avoiding triggers and regular use of antihistamines, the disease can be effectively controlled.