Key Points
- Alpha-gal syndrome (AGS) is a serious, potentially life-threatening allergic condition that can occur after a tick bite.
- Alpha-gal is a molecule found in in most mammals.
- Symptoms appear after people eat red meat or are exposed to other products containing alpha-gal.
What Is Alpha-gal Syndrome?
Alpha-gal syndrome (AGS) is a serious, potentially life-threatening allergic condition that can occur after a tick bite. It's named for a molecule, galactose-α-1,3-galactose, that's found in most mammals.
Symptoms occur after people eat red meat or are exposed to other products made from mammals. Because of this, AGS is also known as red meat allergy or tick bite meat allergy.
A CDC report showed that between 2010 and 2022, more than 110,000 suspected cases of AGS were identified. However, cases of AGS are not nationally notifiable to CDC, so the actual number of AGS cases in the United States is not known. More data and research are needed to understand how many people are affected by this condition.
Risk factors
AGS is associated with tick bites. In the United States, AGS is primarily associated with the bite of a lone star tick, but other kinds of ticks have not been ruled out.
Most reported cases of AGS in the United States occur in the South, East, and Central states. These are the areas where most lone star ticks are found. In other countries, other tick species have been linked to AGS.
While people in all age groups can develop AGS, most cases have been reported in adults.
Causes
While AGS is associated with tick bites, more research is needed to understand the role ticks play in starting this condition, and why certain people develop AGS.
Prevention
Preventing tick bites is important and may reduce your chances of developing AGS or other illnesses.
Before you go outdoors:
- Avoid grassy, brushy, and wooded areas where ticks may be found.
- Walk in the center of trails.
- Treat clothing and gear with permethrin, or buy pre-treated items.
- Use Environmental Protection Agency (EPA)-registered insect repellent.
After you come indoors:
- Check your clothing for ticks.
- Examine gear and pets for ticks.
- Shower and perform a thorough tick check.
If you see an attached tick, remove it immediately.
Learn how to prevent ticks on your pets and in your yard.
Diagnosis
A healthcare provider may diagnose AGS by:
- A physical examination
- A detailed patient history
- A test for antibodies your body produces in response to alpha-gal
Your healthcare provider may also recommend allergy skin testing.
Living with AGS
AGS should be managed under the care of an allergist or other healthcare provider.
Most healthcare providers recommend patients with AGS stop eating meat from mammals, such as beef, pork, lamb, venison, or rabbit. However, not all patients with AGS have reactions to every ingredient containing alpha-gal.
You will need to work with your healthcare provider to understand which products containing alpha-gal you will need to avoid.
Read food product labels carefully.
Prevent tick bites. New tick bites may reactivate allergic reactions to alpha-gal.
Talk to your healthcare provider before taking a new medication or receiving a vaccine. Although very rare, some people with severe AGS may react to ingredients in certain vaccines or medications.