Potentially life-threatening emergency
Alpha-gal syndrome
Alerts and Notices
Synopsis
Individuals with elevated IgE titers to alpha-gal have experienced symptoms of urticaria, gastrointestinal distress, angioedema, and/or anaphylaxis immediately or 3-6 hours (delayed onset) after ingesting mammalian meat (eg, beef, pork) or being exposed to alpha-gal in products made from mammals (eg, medications, cosmetics, vaccines, gelatin, milk products). Implicated tick bites have been noted to be associated with pruritus for 2 or more weeks.
The other reaction seen in patients with IgE to alpha-gal is an immediate onset of anaphylaxis during first exposure to intravenous (IV) cetuximab, an epidermal growth factor receptor (EGFR) inhibitor used for the treatment of colorectal cancer, metastatic non-small cell lung cancer, and head and neck cancer.
A blood test for these IgE antibodies exists.
Delayed diagnosis and treatment of anaphylaxis of any cause predicts poor prognosis. Immediate management involves removal of the triggering allergen if possible, epinephrine by intramuscular injection, and further evaluation and management.
IgE to alpha-gal has been identified in some Sub-Saharan African populations where it is thought to be due to exposure to cestodes, nematodes, scabies, ticks, and a variety of other ectoparasites. Interestingly, however, there have been no reports of delayed anaphylaxis upon exposure to red meat in this population.
Codes
ICD10CM:Z91.014 – Allergy to mammalian meats
SNOMEDCT:
418815008 – Allergy to red meat
Look For
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Diagnostic Pearls
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Differential Diagnosis & Pitfalls
- Other etiologies of anaphylaxis
- Food allergies (eg, food protein-induced enterocolitis syndrome)
- Chronic idiopathic urticaria
Best Tests
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Management Pearls
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Therapy
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Drug Reaction Data
Below is a list of drugs with literature evidence indicating an adverse association with this diagnosis. The list is continually updated through ongoing research and new medication approvals. Click on Citations to sort by number of citations or click on Medication to sort the medications alphabetically.Subscription Required
References
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Last Reviewed:09/27/2017
Last Updated:02/22/2021
Last Updated:02/22/2021