Alpha-gal syndrome is the name for a red meat allergy that develops after a tick bite. Alpha-gal syndrome is rare. But as climate change leads to warmer winters and longer, hotter summers, tick populations are growing and spreading to new areas, increasing the threat of all tick-borne illnesses, including alpha-gal.e60dc2a1-f33c-4a05-9b50-8e3e8e597629a40c109a-5369-4aec-98c2-a84ca69fca6e
Overview Overview What Is Alpha-Gal Syndrome? Alpha-gal syndrome (AGS) is a tick-borne condition in which people become allergic to galactose-α-1,3-galactose, also known as alpha-gal, a sugar found in the tissues of most mammals except for humans and primates. It’s also called mammalian meat allergy, alpha-gal allergy, red meat allergy, and tick bite meat allergy. Symptoms of alpha-gal syndrome can range from mild to severe. There is no cure but the syndrome often goes away or improves on its own within a year or two.e60dc2a1-f33c-4a05-9b50-8e3e8e597629918bbbec-0b53-42ee-a097-f9e6d4f70d05
Signs and Symptoms of Alpha-Gal Syndrome Symptoms Symptoms of alpha-gal typically occur two to six hours after red meat is consumed and include:e60dc2a1-f33c-4a05-9b50-8e3e8e59762974eaf482-d0d1-4bba-b778-17d69621e118 Nausea Diarrhea Heartburn Hives Vomiting Abdominal cramps and pain Bloating Constipation Anaphylactic shock (a potentially deadly reaction) Women are more likely than men to report gastrointestinal symptoms, and nearly half of AGS patients experience at least one gastrointestinal symptom. Many people with alpha-gal don’t have a reaction every time they eat red meat.
Causes and Risk Factors of Alpha-Gal Syndrome Causes Scientists are still working to better understand alpha-gal syndrome, but they have identified a few factors that increase risk. Tick Bites In the United States, alpha-gal syndrome is primarily caused by the lone star tick, which can transfer the alpha-gal sugar molecule into the body. Some people have a strong immune response to these molecules and develop antibodies against them, leading to allergic reactions when eating red meat. Alpha-gal syndrome is more common in areas where lone star ticks are prevalent, such as the southeastern United States and parts of the mid-Atlantic. But because of the increasing prevalence of AGS beyond these areas, experts suspect that the syndrome could be caused by bites from other types of ticks, or by chiggers, a close relative of the tick.e60dc2a1-f33c-4a05-9b50-8e3e8e5976292b110856-d7b5-478c-9fbe-5b21b16f9ff0 The Centers for Disease Control and Prevention (CDC) recently reported two cases of alpha-gal not caused by the lone star tick: one linked to a western black-legged tick, the second linked to a black-legged tick.e60dc2a1-f33c-4a05-9b50-8e3e8e597629ddc9ded2-d788-494c-a0bd-df43c20ff712e60dc2a1-f33c-4a05-9b50-8e3e8e597629df8d54c4-1df9-4781-bfac-c095937c7c3b Outdoor Activities Spending time outdoors, especially near woodland areas, increases the likelihood of developing alpha-gal syndrome. Age People of any age can develop alpha-gal syndrome, but most cases have been in adults.e60dc2a1-f33c-4a05-9b50-8e3e8e5976294ca7f755-2da9-4508-8a87-6161ae027a0b
How Is Alpha-Gal Syndrome Diagnosed? Diagnosis Alpha-gal syndrome is diagnosed by:e60dc2a1-f33c-4a05-9b50-8e3e8e5976292f5d1b47-a7f7-473a-8347-2d0125916a02 A physical exam A detailed patient history, including a thorough history of symptoms An immunoglobulin E test (IgE) to detect the allergic antibody In some cases, allergy skin testing AGS can be difficult to diagnose because some people who have it may not react to red meat every single time they eat it. It is often misdiagnosed as GI conditions like irritable bowel syndrome (IBS) .e60dc2a1-f33c-4a05-9b50-8e3e8e59762995a26252-c3e0-4926-a19d-f050b1a251df
Treatment and Medication Options for Alpha-Gal Syndrome Treatment There isn’t a cure for alpha-gal syndrome but there are ways to minimize symptoms. Allergy Medications Antihistamines can help people with mild reactions to eating red meat. Severe allergic reactions, such as anaphylaxis, may require epinephrine. Oral cromolyn solution may help with gastrointestinal symptoms.e60dc2a1-f33c-4a05-9b50-8e3e8e597629ce0aab76-a029-4233-881b-b90fb25187b3 Dietary Changes This is the primary way of minimizing alpha-gal symptoms.e60dc2a1-f33c-4a05-9b50-8e3e8e597629ce0aab76-a029-4233-881b-b90fb25187b3 Avoid red meat and mammalian products. This is crucial to prevent allergic reactions. This includes cutting out beef, pork, lamb, venison, goat, and rabbit. Avoid dairy products. Dairy products also contain the alpha-gal sugar, though at lower levels than meat. An estimated 5 to 20 percent of people with alpha-gal have allergic reactions to dairy. In people whose alpha-gal symptoms are not adequately controlled through meat avoidance alone, cutting out dairy may be necessary. Avoid gelatin. A small percentage of people with alpha-gal syndrome may have to limit foods that contain gelatin, an animal product, such as marshmallows, jelly beans, and Jell-O. Medication Avoidance Many medications contain ingredients derived from mammals. People with alpha-gal syndrome should avoid these medications and medical products:e60dc2a1-f33c-4a05-9b50-8e3e8e59762905943a54-46ca-4eb4-8228-0f4e4ecee017 Cetuximab (a chemotherapy drug) Gelatin-based colloid plasma substitute (used to treat hypovolemia, a condition in which there is a decrease in the volume of blood circulating in the body) Thyroid hormone supplements derived from cows or pigs Anti-snake venom therapy derived from horses or sheep A small number of people with AGS may need to additionally avoid the following animal-derived products: Heparin (a blood thinner) Pancreatic enzymes (derived from pigs) Gel capsules Vaccines that contain gelatin (such as the measles, mumps, and rubella [MMR] and yellow fever vaccines) Prosthetic heart valves from cows or pigs
Prevention of Alpha-Gal Syndrome Prevention Tick bite prevention is the best way to avoid getting alpha-gal.e60dc2a1-f33c-4a05-9b50-8e3e8e5976298a83fac6-aac5-44cf-9c40-0cbc5bbeb631e60dc2a1-f33c-4a05-9b50-8e3e8e597629ff6d5eea-1b32-4cd3-94ea-3a657ef5750b Avoid ticks when possible. Don’t go off trails in wooded and grassy areas. Use insect repellant with at least 20 percent DEET. Apply permethrin products to clothing, or buy pretreated clothing. Check for ticks after outdoor activities, and if you have one, remove it immediately, using tweezers to grab the tick near its head or mouth. Wear protective clothing like long sleeves. Tuck socks into shoes and pants.
How Long Does Alpha-Gal Syndrome Last? Prognosis Alpha-gal syndrome can persist for years, but symptoms may improve or even go away entirely over time. Some people with alpha-gal syndrome can eat mammal food products again after one or two years, especially if they don’t get any more tick bites. The condition can return if a person is bitten again by a tick.e60dc2a1-f33c-4a05-9b50-8e3e8e5976296d368aa4-c759-4944-a152-4c7218e5b6e3 The overall outlook for alpha-gal syndrome is good if you follow your treatment plan and your health provider’s recommendations.e60dc2a1-f33c-4a05-9b50-8e3e8e59762998d5e76b-20f0-48ca-b709-5255b8ebfcd1
How Many People Have Alpha-Gal Syndrome? Prevalence Awareness of alpha-gal syndrome has grown in the past decade, but it can still be hard to diagnose, and so many cases might be missed. It’s estimated that between 96,000 and 450,000 people in the United States have been affected by AGS since 2010.e60dc2a1-f33c-4a05-9b50-8e3e8e597629ca97a7ab-1566-4d25-bcb4-89c3f493d78e
The Takeaway Alpha-gal syndrome is a rare but serious allergy triggered by tick bites that can cause severe reactions to red meat and other mammalian foods. There is no cure for AGS, but people can minimize symptoms by avoiding mammalian meat and other foods and medicines derived from animal products. Prevent tick bites and alpha-gal infection by using bug repellents, avoiding outside activities in areas where ticks thrive, and checking for and removing ticks as soon as possible. If you suspect you have alpha-gal syndrome, it’s essential to get tested by an allergist and eliminate red meat from your diet to manage symptoms.
Resources We Trust Cleveland Clinic: Alpha-Gal SyndromeCenters for Disease Control and Prevention: Products That May Contain Alpha-GalYale Medicine: Alpha-Gal SyndromeUnited States Environmental Protection Agency: Tips to Prevent Tick BitesAmerican Gastroenterological Association: Diagnosis and Management of Alpha-Gal Syndrome
