What further testing is needed?
Explanation to Question 7
Pollen-food allergy syndrome (PFAS), also known as oral allergy syndrome (OAS), is an IgE-mediated reaction that affects the oropharynx. It is thought to occur from the cross-reactivity between proteins present in pollens and those expressed by fruits and vegetables. Patients develop tingling and itching of the lips, tongue and palate when eating certain raw fruits and vegetables. Systemic signs are very rare. Symptoms do not occur when the fruit or vegetable is cooked. Specific fruits and vegetables are associated with certain types of pollen. For example, birch pollen allergy can have cross reactivity with apples, plums, peaches, nectarines, cherries, and almonds. Patients with allergic rhinitis secondary to ragweed pollen may have cross reactivity with melons, bananas, and tomatoes. Grass pollens cross react with melons and kiwi fruit. This syndrome affects up to 50% of adults with allergic rhinitis secondary to pollens. Pollen-food allergy syndrome can be confirmed through skin prick testing to the fresh foods and pollen, and also with oral food challenges, though oral challenges are rarely necessary.
Symptoms of PFAS can sometimes be controlled with antihistamines. Patients should avoid consumption of the raw food product that produced symptoms but they may continue to eat the specific food if it is cooked. Any patient who has a history of systemic symptoms should strictly avoid the food in all forms and carry an epinephrine auto-injector.
The correct answer is C, skin prick testing for banana and pollens would be appropriate to confirm a diagnosis of pollen food allergy syndrome.
Sources:
1. Tatachar P, Kumar S. Food-induced anaphylaxis and oral allergy syndrome. Pediatr Rev 2008; 29:e23-27.
