Tick bite may cause red meat allergy

People whohave been bitten by a tick, may develop an allergy to red meat, U.S. researchers say. Dr. Susan Wolver and Dr. Diane Sun of Virginia Commonwealth University said delayed anaphylaxis -- a severe, life-threatening allergic reaction -- to meat is a new syndrome identified initially in the southeastern United States. Patients may wake up in the middle of the night, with hives or anaphylaxis -- a life-threatening type of allergic reaction -- 3-6 hours after having eaten red meat for dinner. Wolver, Sun and colleagues analyzed three patient case studies and said the reaction might be caused by antibodies to a carbohydrate -- alpha-gal -- that were produced in a patient's blood in response to a Lone Star tick bite. This carbohydrate substance is also present in meat, so when an individual who has been bitten by a tick eats the meat, his or her immune system activates the release of histamine in response to the presence of alpha-gal, which can cause hives and anaphylaxis, the researchers said. "Where ticks are endemic, for example in the southeastern United States, clinicians should be aware of this new syndrome when presented with a case of anaphylaxis," Wolver said in a statement. "Current guidance is to counsel patients to avoid all mammalian meat -- beef, pork, lamb and venison." The findings were published in the Journal of General Internal Medicine.