Imagine eating your favorite juicy steak or indulging in a delicious hamburger, only to find that shortly after, you experience a puzzling and distressing allergic reaction. This confusing scenario is a reality for an increasing number of individuals who have developed a meat allergy after being bitten by ticks. While most tick bites might lead to common symptoms such as itchiness or mild swelling, some unfortunate victims find themselves grappling with a meat allergy due to a specific protein transmitted by ticks.
Known as alpha-gal syndrome (AGS), this unique form of food allergy is triggered by the bite of a tick, with growing evidence specifically identifying the lone star tick in the United States. The saliva of these ticks contains a sugar molecule called alpha-gal, which our bodies may mistakenly recognize as a harmful substance. Consequently, our immune system generates antibodies to fight against alpha-gal. The problem arises when we consume meat from mammals (beef, pork, rabbit, or lamb, venison, etc.) and products from mammals, as they naturally contain alpha-gal. When the allergic individual ingests meat, the body perceives the alpha-gal as a threat, releasing histamines and causing a wide range of symptoms, usually within 2-6 hours of eating meat or dairy products.
Symptoms may include:
- Hives or itchy rash
- Nausea or vomiting
- Heartburn or indigestion
- Diarrhea
- Cough, shortness of breath, or difficulty breathing
- Drop in blood pressure
- Swelling of the lips, throat, tongue, or eye lids
- Dizziness or faintness
- Severe stomach pain
To diagnosis alpha-gal syndrome requires a positive lab test and a clinical exam, which is cause for concern considering recent studies have shown that many healthcare providers in the United States are not familiar with the potentially life-threatening allergic condition. In a separate investigation, researchers from the CDC analyzed laboratory tests from a primary commercial lab from 2017 to 2022. All the specimens submitted were gathered from patients showing presumed clinical suspicion of alpha-gal syndrome. Of the more than 300,000 specimens analyzed, over 30 percent tested positive for AGS.
Melissa is a Training Manager for Education and Institutional Preparedness for the SPECTRE program.
Resources
For more information about alpha-gal syndrome: https://www.cdc.gov/ticks/alpha-gal/index.html
For more information about the recent uptick in positive cases: https://www.cdc.gov/media/releases/2023/p0727-emerging-tick-bites.html
For tips on avoiding tick bites: https://www.cdc.gov/ticks/avoid/on_people.html