Dr. Chad Mayer, Director of the Comprehensive Food Allergy Clinic at the Allergy & Asthma Institute of SE Michigan in West Bloomfield, advises holiday cooks and hosts to be careful this holiday season when preparing and serving food. Cross contamination, or transferring ingredients from one food to another food, occurs easily while preparing and serving holiday meals. This puts a food allergic person at higher risk for an allergic reaction.

According to Dr. Mayer, a food allergy is an immune system response to a food that the body mistakenly believes is harmful. The body then releases a number of chemicals, including histamine, to protect itself. These potent chemicals can trigger many allergic symptoms that can affect the respiratory system, gastrointestinal tract, skin or cardiovascular system. In some cases, this may be confused with food intolerance (i.e. lactose intolerance) or food poisoning. Among the reactions to an offending food item are nausea, vomiting, diarrhea, hives, wheezing, tongue and throat swelling, drop in blood pressure and death. While a mild allergic reaction such as hives may be treated with an antihistamine, a more significant reaction requires physician prescribed epinephrine. Significant reactions are those with more than one symptom, with or without respiratory symptoms. With any significant allergic reaction, 9-1-1 should be called whether epinephrine was administered or not.

Dr. Mayer says that the most common childhood food allergies are milk, eggs, soy, wheat, peanuts and tree nuts. Adults are likely to have reactions from fish or shellfish as well as peanuts and tree nuts.

Dr. Mayer calls the buffet style of serving foods during the holidays “a dangerous setting to be in when people have food allergies.” He adds that serving spoons often go from one dish to another, causing cross contamination-spreading the allergy-causing ingredients to the non-allergy-causing foods.

Many holiday hosts set out a dish of nuts or candies for guests to enjoy. Additionally, there are many holiday dishes containing allergens, including nuts; many times the allergen is hidden. These are a great concern for those with food allergies, particularly those with peanut or tree nut allergies.

About 8 percent of children and 4 percent of adults have food allergies. According to the Asthma & Allergy Foundation of America, food allergies account for about 30,000 emergency room visits and 200 deaths each year.

To determine if a patient has a food allergy, doctors perform a Skin Prick Test (SPT) or a blood test called RAST. A positive test indicates the possible association between the food being tested and the patient’s reaction to the food. However, Dr. Mayer notes, that in general only about 60% of patients with a positive SPT or approximately 50% patients with a positive RAST will have symptoms from ingesting that food. A positive test only suggests sensitivity to the food. The test must be correlated with the patient’s history or a physician monitored oral challenge to make an accurate diagnosis of food allergy.