Surprisingly large number of people may have marker for tick-linked meat allergy
A new study finds that in some parts of the US, up to 30% of people carry antibodies for tick-induced red meat allergy, far exceeding the number of diagnosed cases.
According to a study published in Morbidity and Mortality Weekly Report, up to 30% of people in some US regions may carry the antibody behind a red meat allergy triggered by tick bites. This is far higher than the estimated number of people who actually have the allergy. The Centers for Disease Control and Prevention previously estimated that only 0.14% of the US population (up to 450,000 people) has the allergy. The findings suggest many more Americans may be at risk, as the allergy can make eating a hamburger a potentially life-threatening choice.
The study surveyed blood donations for the key antibody, which belongs to the IgE class and specifically attacks a double-sugar molecule called galactose-α-1,3-galactose, or alpha-gal. This disaccharide is found on cells of nonprimate mammals like cows and pigs, but is also released in tick saliva, particularly from the lone star tick (Amblyomma americanum). People bitten by ticks can develop IgE antibodies against alpha-gal, which can sometimes trigger an allergic response to red meat and other animal products such as dairy and gelatin.
The allergy, known as alpha-gal syndrome, is notorious for its delayed onset, appearing two to six hours after a meal, making it hard to link the reaction to food. Symptoms can include hives, nausea, vomiting, abdominal cramps, diarrhea, and signs of anaphylaxis, such as trouble breathing, throat tightening, swollen tongue or lips, dizziness, weak pulse, and a drop in blood pressure. The study highlights how little is understood about this unique disease and the challenges of accurate diagnosis.
