Oral immunotherapy can trigger a severe allergic reaction/anaphylaxis which can be life-threatening. The most common side effects were abdominal pain, vomiting, throat irritation/tightness, cough, wheezing, shortness of breath, nasal symptoms including runny nose/sneezing, and itchy skin/mouth/ears and hives. OIT is NOT recommended for patients with uncontrolled asthma, history of mastocytosis or eosinophilic esophagitis, or who are unable to receive or self-administer injectable or nasal epinephrine.

Allergic reactions are more likely in the presence of cofactors such as exercise, illness/active infection, fasting, hot water exposure, sleep deprivation, menstruation, and recent NSAID use. Patients should adjust the dose at home according to the doctor’s recommendations in the presence of these cofactors. Severe reactions which occur during treatment will need to be treated with injectable epinephrine, as well as evaluation at the nearest emergency room or urgent care clinic.

Oral immunotherapy can also cause inflammation of the esophagus (eosinophilic esophagits) and cannot be given to a patient with preexisting eosinophilic esophagitis or other eosinophilic gastrointestinal disease. The symptoms of this condition include trouble swallowing, food becoming stuck in the throat or chest, abdominal pain, and vomiting.