Patient J is a man, 35 years of age, who presents to the emergency room with acute dysphagia, vomiting, and abdominal pain. The symptoms began when he was having lunch at work, and they have persisted for a long period of time. The patient has a history of indigestion, asthma, and atopic dermatitis. The symptoms appear to be indicative of gastroesophageal reflux disease, and lansoprazole, 30 mg daily is prescribed. However, because the patient has a history of atopy and the onset of symptoms was acute, he is referred to a gastroenterologist for additional work-up.

The gastroenterologist performs an upper endoscopy with biopsy to determine if the symptoms are the result of an allergic response. Endoscopic examination shows the esophagus to be pink with linear furrows. Analysis of the biopsy samples demonstrates increased levels of eosinophils, approximately 26 per high-power field, in samples taken from the esophagus but not in those taken from the stomach or duodenum. Given the history of atopy, the results of the endoscopy and analysis indicate eosinophilic esophagitis.

The patient is referred to an allergist for testing to determine the allergen responsible for the response. Results of the skin prick tests demonstrate a response to bananas and honey. Patient J has eliminated these food items from his diet, and symptoms have resolved without recurrence.

A woman brings her son, Patient M, 1 year of age, to the pediatrician because of a persistent rash on the child's face, arms, and legs. The history regarding dietary intake indicates that cow's milk was newly introduced into Patient M's diet. Furthermore, the child's mother has a history of asthma and remembers that she drank soy milk as a child because she was allergic to cow's milk. On examination, Patient M's rash is limited to his cheeks and the extensor surface of his arms and legs. The rash is raised and intensely pruritic, with some small erythematous patches. The child has no respiratory or gastrointestinal symptoms and is afebrile. It is suspected that the patient is having an IgE-mediated response to cow's milk manifesting as atopic dermatitis. An immediate referral to an allergist is made, and the mother is advised to remove milk from the child's diet.

After reviewing Patient M's history and to confirm the initial diagnosis of IgE-mediated atopic dermatitis, the allergist performs a skin prick test. There is a positive response to cow's milk, with a wheal 6.5 mm in diameter. No reactions to other substances are noted. The positive reaction on the skin test and the family history of milk allergy negate the need for additional tests to confirm the diagnosis. Management includes removal of milk from Patient M's diet and treatment of pruritus with children's strength diphenhydramine (Benadryl) and a topical steroid cream. A follow-up appointment is made to monitor Patient M's allergy status.

Patient A is a woman, 21 years of age, with a known allergy to peanuts. She was having dinner at a Chinese restaurant with friends when she began to experience trouble breathing, which progressed to wheezing within a few minutes. She also showed signs of confusion and had slurred speech. Emergency response personnel were summoned to the scene.

On arrival, emergency personnel note diffuse and severe urticaria on Patient A's arms, legs, and face, particularly around the eyes and mouth. The patient also appears to have angioedema of the throat and/or tongue. Examination reveals pulmonary edema and a pulse of 140 beats per minute. The woman's friends tell the emergency response personnel that she has a peanut allergy. During transportation of the patient to the local hospital, an endotracheal tube is placed to create a patent airway, and 0.3 mg of epinephrine is administered intramuscularly in the thigh. After the epinephrine is administered, Patient A's symptoms begin to clear.

When the patient arrives at the hospital, she has a pulse of 100 beats per minute and her breathing is substantially improved. Intravenous corticosteroid is given in order to minimize lingering allergic response. It is determined that, although the patient did not intentionally consume peanuts, there had been some cross contamination at the restaurant, which does serve several dishes containing peanuts or peanut butter. Because Patient A has a known allergy, she has a prescription for self-injectable epinephrine. However, she states that she usually leaves the medication at home because she avoids peanuts and, therefore, has had no need for it. The patient is advised to always keep the self-injectable epinephrine with her and to tell friends and companions where the medication is and when to use it. It is also recommended that she wear a necklace or bracelet identifying her severe peanut allergy in order to assist emergency personnel in the future.