Potential triggers include direct mechanical friction or trauma as well as viral infections, and thus affected children should avoid contact sports and mitigate exposure to ill children (i.e., early daycare) The transition to puberty may increase the frequency, severity, and duration of acute episodes Other reported triggers include stress, dental manipulation, and medications including estrogen therapies and angiotensin-converting enzyme inhibitors Goals of Treatment Treating acute attacks of swelling includes rapid, controlled airway management in cases of laryngeal edema, and prompt administration of C1-esterase inhibitor concentrate (or alternative therapy) to reduce morbidity and mortality Clinical Considerations Clinical Recognition Diagnosis of hereditary angioedema early in life is critical but often delayed A complete history and physical examination should be performed including a detailed assessment of the airway, posterior pharynx, and abdomen Abdominal ultrasonography may be useful in discriminating angioedema from a surgical process Ultrasound findings consistent with an acute attack include bowel hyperemia and ascites Patients may report a prodrome of paresthesias at the location of developing edema Episodes are self-limited, but may last for to days Laboratory Assessment The diagnosis is suspected with normal C3 and low C4 levels secondary to increased conversion of C4 to C1 Functional and antigenic C1-inhibitor levels should be obtained but may be falsely low in children younger than years of age Management Initial management of acute attacks includes airway evaluation and management, fluid resuscitation, and pain control Intubation should be considered for patients with dysphagia, stridor, voice changes, or dyspnea Because of the potential for significant airway edema with landmark distortion, laryngoscopy should ideally be performed in a setting equipped to perform a surgical airway as indicated Unfortunately, unlike anaphylaxis, epinephrine (IM or nebulized), corticosteroids, and antihistamines are usually ineffective in the management of hereditary angioedema Therefore, use of these therapies should never precede definitive airway management