TABLE 1.
Useful Questions for Assessment of Food Allergy
| Question | Rationale |
|---|---|
| What was the timing of the reaction? | An IgE-mediated reaction occurs rapidly after food ingestion. Symptoms occurring more than 2 hours after ingestion are unlikely to be related to the food, except in the case of diarrhea, which can occur up to 6 hours later. Immediate symptoms may, however, be followed by a delayed phase reaction that occurs hours to several days later. It usually involves the skin, bronchi or GI tract. 2 |
| Were there reactions to this food in the past? | Although a reaction can present with a food that was previously tolerated, patients will often report previous minor symptoms with the food, such as mild pruritis, local hives or nausea. |
| Has your child eaten the food since? | Once sensitized, reaction should be systematic with every contact with the food. If the food was ingested and tolerated after the initial reaction, allergy to that food is basically ruled out. |
| How much food is needed to trigger the reaction? | Allergies usually require only a very small amount of the food to trigger a reaction. A patient reporting symptoms only to large quantities of a food suggests intolerance rather than allergy. |
| Does the reaction occur without exposure the food? | Children with chronic urticaria or dermographism often present local hives with spicy or acidic food (tomatoes, strawberries) that induce non-specific degranulation of mast cells. |
| Was the food cooked? | Symptoms to fresh food only suggest sensitization to a thermolabile allergen. |
| Did your child have fever (or other signs of viral infection)? | Viral infection is an important differential diagnosis of food allergy and should be sought. |
| Did anyone else have symptoms? | If others present with similar symptoms to the food, intoxication becomes more probable. |
| Does your child suffer from other allergies? | Atopic children are more likely to become sensitized to a food. 30% to 40% of children with atopic dermatitis will eventually develop a food allergy. If the patient has other food allergies, possibility of contamination or cross-reactivity should be considered.8,9 |
| Was there a concurrent use of alcohol, NSAIDs or exercise? | Alcohol intake, NSAIDs or exercise decrease reaction threshold. Some patients with oral allergy syndrome or wheat allergy will only present symptoms if they exercise before or after eating the food. 2 |
IgE = immunoglobulin E; GI = gastrointestinal; NSAID = nonsteroidal anti-inflammatory drug.