October 2001

By James R. Roberts, MD

In separate cases, two women had complained to their physician of swelling of the tongue. The first patient (left), who awakened with painless unilateral swelling of the tongue, attributed the condition to a known allergic reaction to strawberries, which she had eaten the night before. One month earlier, she had experienced a similar reaction after eating some nuts, but the swelling gradually subsided without treatment. Over the phone, her doctor told her that she probably had an "allergic condition."

The second patient (right) noted an odd swelling under her tongue, thinking that she might have burned it while drinking hot tea. One month earlier, marked swelling had appeared on her lower lip, a condition her doctor decided was either the result of an insect bite or a sign of an unspecified allergy. The swelling gradually subsided after prednisone and diphenhydramine therapy, and afterward she was scheduled to undergo skin testing for allergy. Neither woman had pruritus, skin rash, wheezing, shortness of breath, or swelling in other areas of the body. For more than six months, each patient had been taking a different angiotensin-converting enzyme (ACE) inhibitor medication to control blood pressure, neither of which had caused any problems known to be associated with it. For both women, the swelling gradually disappeared in the emergency department after antihistamine therapy. What caused the angioedema in both women?

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ANSWER

One of the ACE inhibitors was enalapril and the other a combination of captopril and a diuretic. The women had tolerated the medications well for many months before symptoms developed. Because the previous swelling was only minimally annoying and had disappeared while the women were taking the antihypertensive agents, neither they nor their treating physician suspected the condition might be a reaction to the drugs. In fact, their response was not a true IgE-mediated allergic reaction but rather an unpredictable idiosyncratic angioedema, a classic presentation. This bizarre syndrome is related to a build-up of bradykinin.

Not all patients with this reaction are so fortunate, however. I have seen one woman come close to respiratory arrest after enduring massive tongue and upper airway swelling for nearly a year. Fortunately, airway patency was restored by a nasotracheal tube, placed with guidance from a bronchoscope. However, an attempt at tracheostomy, indeed a most difficult procedure under such circumstances, was unsuccessful.

The key point to remember is that minor episodes of ACE inhibitor-induced angioedema can occur even when patients have not changed the drug dosage or taken new medications. When such a reaction occurs, a different class of antihypertensive agent should be tried, since any ACE inhibitor can produce this effect.

No effective medical therapy for airway edema is currently available. Epinephrine, antihistamines, and steroids are often used to treat angioedema, but as the drugs do not produce an adequate response, an artificial airway is instead sometimes necessary. The trick is to protect the airway before the swelling becomes a life-threatening emergency.

Emerg Med 33(10):44, 2001

Dr. Roberts is professor of emergency medicine at the Medical College of Pennsylvania and chairman of the department of emergency medicine at Mercy Catholic Medical Center in Philadelphia. He is also a member of the Emergency Medicine editorial board.