Clinical impact of peripheral attacks in hereditary angioedema patients

Episodes of acute subcutaneous angioedema affecting the extremities in patients with known hereditary angioedema are called peripheral attacks. These attacks are considered to be of limited clinical importance.

To evaluate the impact of peripheral attacks in patients with hereditary angioedema and to assess the response to treatment with recombinant human C1-inhibitor (rhC1INH).

Hereditary angioedema patients with a peripheral attack included in a clinical database of rhC1INH were analyzed. Visual analog scale (VAS) scoring was used to evaluate symptom severity and response to therapy.

Sixty-five patients with a peripheral attack were identified. VAS scores for 64 patients were available. Twenty-nine (45%) patients reported a single peripheral location of the attack, the others multiple locations. Eight patients (13%) indicated moderate (VAS 20-50 mm) and 55 (86%) severe (VAS ≥50 mm) swelling, 17 (27%) had moderate and 35 (55%) severe pain, while 8 (13%) patients reported moderate and 51 (80%) severe dysfunction for the peripheral attack. Symptom VAS scores decreased over time more rapidly in patients treated with rhC1INH than in patients treated with placebo. Onset of relief was achieved in 95% of the rhC1INH-treated patients within 4 hours, whereas only 21% of saline-treated patients had relief in the same time period.

Peripheral attacks in hereditary angioedema patients often are located at multiple anatomical locations and frequently have associated pain and dysfunction, in addition to swelling, as dominant symptoms. The medical need for treatment of these attacks may be underestimated. Treatment with rhC1INH constitutes a therapeutic option for acute peripheral hereditary angioedema attacks.