Penile Angioedema After Peanut Ingestion

A 6-year-old boy presented with a swollen penis and lip within an hour after ingesting some peanuts. The swelling was nonpruritic. The child described a sense of tightness in the lips. He had no associated rash, abdominal pain, dysphagia, stridor, dyspnea, dysuria, or abnormality in the urinary stream. He was not taking any medications. He had no history of a recent viral infection, insect bite or sting, oral or genital trauma, or blood transfusion. There was no family history of asthma, atopic dermatitis, allergic rhinitis, or angioedema.

Examination revealed no signs of an allergic reaction other than the angioedema of the lips and penis. The foreskin could be retracted, and the urethral meatus was normal. The child was treated with hydroxyzine, 10 mg orally 4 times a day. The angioedema subsided within 72 hours.

Angioedema is most commonly caused by a type I-anaphylactic or IgE-mediated-immediate hypersensitivity reaction to food (notably, peanuts, cow’s milk, eggs, chocolate, or seafood), drugs (notably, antibiotics, opiates, or sedatives), stinging insect venom, preservative, latex product, or aeroallergen. Angio edema may also be a consequence of a type II cytotoxic reaction (transfusion reaction) or a type III antigen-antibody complex reaction (serum sickness). Vibratory angioedema and exercise-induced angioedema result from hypersensitivity to a mechanical or physical factor. Hereditary angioedema is an autosomal dominant disorder associated with the absence or dysfunction of C1 inhibitor.

FOR MORE INFORMATION:
• Estrada JL, Gozalo F, Cecchini C, Casquete E. Contact urticaria from hops (Humulus lupulus) in a patient with previous urticaria-angioedema from peanut, chestnut and banana. Contact Dermatitis. 2002;46:127. • Leung AK, Robson WL. Penile and oral angioedema associated with peanut ingestion. J Natl Med Assoc. 2006;98:2011-2012.
• Smith GA, Sharma V, Knapp JF, Shields BJ. The summer penile syndrome: seasonal acute hypersensitivity reaction caused by chigger bites on the penis. Pediatr Emerg Care. 1998;14:116-118.