Perinatal Characteristics of Japanese Children With Infantile Hemangioma: A Questionnaire‐Based Case–Control Study

Infantile hemangioma (IH) is the most common vascular tumor in infants. Clinical and perinatal data from Japanese hospital-based studies are limited. We performed a questionnaire-based case-control study to describe the clinical characteristics of IH and evaluate the factors associated with IH. The study included 150 children with IH and 150 pediatric dermatological controls without IH who visited our hospital. IH was diagnosed by direct dermatological examination in all cases, and questionnaires were administered during hospital visits. The clinical characteristics of children with IH were summarized. Background factors were compared between groups, and factors associated with IH were analyzed using multivariable logistic regression after multiple imputation to calculate adjusted odds ratios (aORs) and 95% confidence intervals (CIs). Among 150 children with IH, 124 (82.7%) had a single lesion, and 26 (17.3%) had multiple lesions. The most frequent lesion sites were the head and neck (n = 64), trunk (n = 51), and upper extremities (n = 39). Children with IH had lower birth weights than controls (2904 ± 474 vs. 3007 ± 391 g; p = 0.041). However, low birth weight (< 2500 g) was not associated with IH after adjustment (aOR 1.65 [95% CI 0.69-3.94]; p = 0.263). Firstborn children were more frequent in the IH group than in the control group (82/150 [54.7%] vs. 63/149 [42.3%]; p = 0.030). In the multivariable analysis, firstborn status remained associated with IH after adjustment (aOR 1.82 [95% CI 1.03-3.20]; p = 0.039). In this Japanese hospital-based case-control study, firstborn status was associated with IH after adjusting for maternal, perinatal, and socioeconomic factors. Although children with IH had a lower mean birth weight than controls, low birth weight (< 2500 g) was not associated with IH in the adjusted model.