Angioedema

Acute angioedema of the upper airways can be life-threatening. An important distinction is drawn between mast-cell-mediated angioedema and bradykinin-mediated angioedema; the treatment of these two entities is fundamentally different.

This review is based on pertinent articles retrieved by a selective search in PubMed and on guidelines concerning the treatment of angioedema. The authors draw on their own clinical experience in their assessment of the literature.

In the emergency clinical situation, the most important information comes from accompanying manifestations such as itching and urticaria and from the patient's drug history and family history. When angioedema affects the head and neck, securing the upper airways is the highest priority. Angioedema is most commonly caused by mast-cell mediators, such as histamine. This type of angioedema is sometimes accompanied by urticaria and can be effectively treated with antihistamines or glucocorticoids. In case of a severe allergic reaction or anaphylaxis, epinephrine is given intramuscularly in a dose that is adapted to the patient's weight (150 μg for body weight >10 kg, 300 μg for body weight >30 kg). Bradykinin-mediated angioedema may arise as either a hereditary or an acquired tendency. Acquired angioedema can be caused by angiotensin converting enzyme (ACE) inhibitors and by angiotensin II receptor blockers. Bradykinin-mediated angioedema should be treated specifically with C1-esterase inhibitor concentrates or bradykinin-2 receptor antagonists.

Angioedema of the upper airways requires a well-coordinated diagnostic and therapeutic approach. Steroids and antihistamines are very effective against mast-cell-mediated angioedema, but nearly useless against bradykinin-mediated angioedema. For angioedema induced by ACE inhibitors, no causally directed treatment has yet been approved.