001125 - Clinical Characteristics and Puberty-Related Changes in Pediatric Hereditary Angioedema

Hereditary angioedema (HAE) is a rare but potentially life-threatening disorder characterized by deficiency or dysfunction of C1 esterase inhibitor. This study aimed to evaluate demographic, clinical, and laboratory characteristics of pediatric patients with HAE, as well as prodromal symptoms, attack triggers, sites of involvement, and changes observed after puberty.

This descriptive, cross-sectional study included 38 pediatric patients diagnosed with hereditary angioedema. Data were obtained from medical records and face-to-face interviews.

The median age was 14.3 years; 52.6% were female, and 89.5% had type 1 HAE. The median age at symptom onset was 4.3 years, and the median age at diagnosis was 4.8 years. Of the patients, 68.4% were pubertal/postpubertal and 31.6% were prepubertal. Thirty-two patients (84.2%) were symptomatic; in this group, the median lifetime number of attacks was 75.5, and the median number of attacks in the previous year was 38. The most frequently affected sites were the upper extremities (84.4%), lower extremities (56.3%), and periorbital region (53.1%), while laryngeal involvement was observed in 15.6%. Prodromal symptoms were reported by 65.6% of patients, most commonly local paresthesia (81.0%), followed by a sense of discomfort (52.4%), nausea and pruritus (28.6%), erythema (23.8%), and fatigue (19.0%). All symptomatic patients identified at least one attack trigger. The most frequent triggers were trauma (78.1%), infection (37.5%), and psychological stress (28.1%); menstruation-related triggering was identified in 12.5% (n=4) of postpubertal girls. A significant increase in annual attack frequency was observed after puberty (p<0.001). This increase was statistically significant in both females [median prepubertal 2.5 (interquartile range [IQR]: 1.0–29.0) vs postpubertal 6.0 (IQR: 1.5–68.5); p=0.011] and males [median prepubertal 6.0 (IQR: 0–24.0) vs postpubertal 42.0 (IQR: 4.0–88.0); p=0.005]. Icatibant (78.1%) and C1-INH concentrate (62.5%) were the most commonly used treatments. Twenty-one patients (55.3%) received short-term prophylaxis, most frequently for dental procedures (95.2%), and no angioedema attacks occurred following these interventions.

Our findings indicate that puberty represents a critical turning point in the disease course of pediatric HAE, with a significant increase in attack frequency. Trauma and infection are the most common triggers, while menstruation constitutes an additional risk factor in postpubertal girls. Prodromal symptoms can be identified during childhood but tend to become more prominent near puberty. These results highlight the importance of considering postpubertal clinical dynamics in the management of pediatric HAE.