Mosquito bite hypersensitivity in children: Clinical features outweigh specific IgE in diagnosis

Background: Mosquito bite hypersensitivity results from abnormal immune responses to salivary proteins with potent immunomodulatory properties. In children, both type I (immunoglobulin E [IgE] mediated) and type IV (cell mediated) mechanisms contribute to the reaction spectrum, ranging from localized erythema to extensive inflammatory lesions. Although mosquito-specific IgE assays are commercially available, their diagnostic utility and correlation with clinical severity remain unclear. Objective: The objective was to describe the clinical and immunologic characteristics of children with mosquito hypersensitivity, evaluate the diagnostic relevance of mosquito-specific IgE, and explore associations with atopic background. Methods: A retrospective study was conducted on 206 children who underwent mosquito-specific IgE testing between June 2023 and June 2025. The mosquito allergy group included children with large local reactions, prolonged lesions, or systemic symptoms; the controls had typical reactions only. Clinical features, atopic comorbidities, total IgE levels, eosinophil percentages, and inhalant sensitizations were compared between the groups. Results: Atopic diseases were significantly more common in the mosquito allergy group versus the controls (87.0% versus 52.7%; p < 0.001). Mosquito-specific IgE positivity was low and similar across the groups (mosquito allergy group 6/77 [7.8%] vs controls 13/129 [10.1%]; p = 0.63), which showed no correlation with reaction type, duration, or severity. The total IgE levels were significantly higher in the mosquito allergy group (p = 0.045). The most frequent lesions were erythematous papules (88.3%) and immediate wheals (89.6%), whereas bullous lesions were rare (7.8%) and self-limited. Quality of life was mainly affected by avoidance of outdoor activities (16.9%) and psychological distress (15.6%). Conclusion: In pediatric mosquito hypersensitivity, clinical assessment outweighs mosquito-specific IgE testing for diagnosis. Despite the strong association with atopy, specific IgE positivity remains low, which supports the primacy of clinical history and lesion morphology in diagnostic decision-making.