Description

The Alpha-GAL IgE test is used to detect a potential allergy to red meat, caused by a sugar molecule called galactose-alpha-1,3-galactose (alpha-gal). This allergy is often triggered by a tick bite and can cause a delayed allergic reaction several hours after consuming mammalian meat such as beef, pork, or lamb.

What It Is

Alpha-GAL Syndrome (AGS) is an allergy to alpha-gal, a sugar found in most mammals—but not in humans or other primates. It is also called:

  • Red meat allergy
  • Tick bite meat allergy
  • Mammalian meat allergy

How It Happens

AGS is usually caused by a tick bite, most commonly from the Lone Star tick in the U.S. When the tick bites, it can transfer alpha-gal into your bloodstream, prompting your immune system to produce antibodies. Later, when you eat red meat containing alpha-gal, your body may react.

Symptoms

Symptoms can range from mild to severe and may include:

  • Severe stomach pain, heartburn, or indigestion
  • Diarrhea
  • Coughing, shortness of breath, or difficulty breathing
  • Drop in blood pressure
  • Swelling of the lips, throat, tongue, or eyelids
  • Hives or rash

Because reactions are often delayed by several hours, they can be difficult to connect directly to red meat consumption without testing.

Fasting: Not required.