. 2023 Jun 6;13(2):60–65. doi: 10.5415/apallergy.0000000000000100

Table 1.

Consensus recommendation 1

For acute attacks of angioedema in patients with HAE:
a. Treatment of each patient needs to be individualized. b. Intravenous pd-C1-INH should preferably be used for all acute attacks. c. Intravenous pd-C1-INH must be used for all acute attacks that involve the larynx and tongue and for all abdominal attacks (Abdominal attacks of HAE are characterized by intense pain often associated with vomiting, diarrhea, bloating, and abdominal distension. It is important to differentiate an acute attack of angioedema affecting the abdomen from other causes of pain such as gastritis.). d. Intravenous pd-C1-INH must be used as soon as possible, preferably within 1 hour of symptom onset and preferably through self-administration at home. e. One should avoid using FFP for on-demand treatment of HAE unless there is no mechanism to arrange pd-C1-INH therapy. f. Recommended dose of intravenous pd-C1-INH is 10 to 20 IU/kg for an acute attack (adult dose is 1000 IU, ie, 2 vials of 500 IU each). However, because some adult patients may respond to even a single vial of 500 IU (when given early in the disease course), it may be advisable to use a smaller dose of 500 IU, especially when pd-C1-INH is being self-administered at home. The dose may be repeated in 2 to 3 hours if there is no adequate response. g. For an acute episode affecting the larynx, it is strongly recommended to use 20 IU/kg or 1000 IU (in adults). h. On-demand treatment during a prodrome is not recommended. Important note: C1-INH has a wide therapeutic index and treatment doses may be rounded up to the nearest vial—even in young children. One should not discard any amount of C1-INH injection. A dose of more than 20 U/kg may safely be used when treating small children.

For acute attacks of angioedema in patients with HAE:

a. Treatment of each patient needs to be individualized.
b. Intravenous pd-C1-INH should preferably be used for all acute attacks.
c. Intravenous pd-C1-INH must be used for all acute attacks that involve the larynx and tongue and for all abdominal attacks (Abdominal attacks of HAE are characterized by intense pain often associated with vomiting, diarrhea, bloating, and abdominal distension. It is important to differentiate an acute attack of angioedema affecting the abdomen from other causes of pain such as gastritis.).
d. Intravenous pd-C1-INH must be used as soon as possible, preferably within 1 hour of symptom onset and preferably through self-administration at home.
e. One should avoid using FFP for on-demand treatment of HAE unless there is no mechanism to arrange pd-C1-INH therapy.
f. Recommended dose of intravenous pd-C1-INH is 10 to 20 IU/kg for an acute attack (adult dose is 1000 IU, ie, 2 vials of 500 IU each). However, because some adult patients may respond to even a single vial of 500 IU (when given early in the disease course), it may be advisable to use a smaller dose of 500 IU, especially when pd-C1-INH is being self-administered at home. The dose may be repeated in 2 to 3 hours if there is no adequate response.
g. For an acute episode affecting the larynx, it is strongly recommended to use 20 IU/kg or 1000 IU (in adults).
h. On-demand treatment during a prodrome is not recommended.
Important note:
C1-INH has a wide therapeutic index and treatment doses may be rounded up to the nearest vial—even in young children. One should not discard any amount of C1-INH injection. A dose of more than 20 U/kg may safely be used when treating small children.

FFP, fresh frozen plasma; HAE, hereditary angioedema; pd-C1-INH, plasma-derived C1-esterase inhibitor.