Two patients presented with a history of anaphylaxis (one with loss of consciousness, the other with laryngeal edema, urticaria, angioedema, and near syncope) immediately after eating chapuline from Oaxaca, Mexico.
Prick puncture testing to grasshopper antigen was 4+ in both patients and negative in five non-allergic controls. Both patients gave a prior history of urticaria/angioedema/laryngeal edema following ingestion of crustaceans. In vitro IgE specific antibodies to crustaceans, dust mites, and cockroach were positive in both patients. Total IgE was greater than 2000 IU/mL in one patient, and 92.6 IU/ mL in the other (nl<87 IU/mL). Tryptase levels in both patients were not elevated. Specific IgE inhibition studies reveal that grasshopper extract contains antigens capable of binding to patient's specific IgE to crustaceans, cockroach, and mites, indicating the presence of a cross reacting pan-allergen in grasshopper extract. Immunoblot analysis of the grasshopper extract revealed the presence of a 30 kD molecular weight protein in grasshopper and chapuline and a 38 kD molecular weight protein in shrimp, which bound patient-specific IgE antibody. Western Blot analysis of the extract probed with anti-tropomyosin antibody revealed those antigens to be tropomyosin.
Although previous reports in the literature of allergic rhinoconjunctivitis, contact urticaria, and asthma after inhalation of grasshopper are well known, this is the first well-documented report of anaphylaxis following ingestion of grasshoppers. Ingestion of insects is very popular in Asia, the Middle East, South and Central America, and particularly in Mexico and in southern California. The purpose of this report is to alert the medical community and the public to the fact that there is an increased risk of allergic reactions to the ingestion of grasshoppers in patients with a prior history of crustacean, house dust mite, and/or cockroach allergy.