Evaluation of allergic diseases in children diagnosed with cutaneous mastocytosis

Background: Cutaneous mastocytosis (CM) is the most common type of mastocytosis in children. The atopy frequency in these patients is typically similar to that in the general population, but a higher incidence of anaphylaxis is reported. Objective: This study aimed to evaluate the presence of allergic diseases in children diagnosed with CM and its impact on clinical manifestations. Methods: Children diagnosed with CM at Ankara Bilkent City Hospital Pediatric Allergy and Immunology Clinic between September 2019 and September 2023 were included in the study. Data, including demographic information, clinical details, and laboratory results, were gathered from medical records, encompassing personal and family allergy history. Results: The study included 58 patients (median [interquartile range{IQR}] age, 64 months [29-100.5 months]; 69% boys) with skin lesions as the primary concern. The median (IQR) age at which the lesions appeared was 9 months (3-39.25 months), and the median (IQR) age at hospital admission was 12 months (5- 50 months). The median (IQR) age at CM diagnosis was 13 months (6-53.5 months). The median (IQR) baseline tryptase value was 5.45 μg/L (3.93-9.00 μg/L), and 16 had an elevated tryptase value (>8 μg/L). Allergic diseases were present in 39.65% of the patients, with atopic dermatitis (18.9%) being the most common, followed by asthma (10.3%), allergic rhinitis (5.2%), food allergy (1.7%), and drug and bee venom allergies (1.7%). One patient had a history of anaphylaxis, diagnosed 4 months after consuming yogurt. A total of 18 patients, including this patient, were prescribed an adrenaline autoinjector. Conclusion: Various allergic diseases occurred in ∼40% of patients with CM and most commonly manifest as atopic dermatitis; 31% patients with risk factors for anaphylaxis were prescribed an adrenaline autoinjector.