What foods should patients with asthma avoid?

Food Avoidance in Asthma Patients

Patients with asthma should only avoid foods if they have a documented IgE-mediated or non-IgE-mediated food allergy confirmed by testing and clinical history—routine food avoidance without proven allergy provides no benefit for asthma control and risks nutritional deficiency. 1

General Principle: No Blanket Food Restrictions

• Avoiding potentially allergenic foods does not improve asthma outcomes in patients without documented food allergy. 1
• Food allergies are rarely an aggravating factor in asthma itself, and empiric elimination diets have not been shown to reduce asthma severity or exacerbation frequency. 1
• Unnecessary food avoidance places patients at risk for nutritional deficiencies and growth deficits without any clinical benefit. 1

Foods to Avoid ONLY If Documented Allergy Exists

High-Risk Foods Requiring Strict Avoidance When Allergic

If your patient has confirmed food allergy (positive testing plus clinical reactivity), these foods warrant complete avoidance:

• Peanuts and tree nuts pose the highest risk for fatal anaphylactic reactions in asthmatic patients and must be strictly avoided if allergy is confirmed. 2, 3
• Fish and shellfish are the second-highest risk category for severe reactions in patients with both asthma and food allergy. 2, 4
• Milk, egg, soy, and wheat should be avoided only if specific allergy is documented, as these are common allergens in children with asthma. 1, 5

Critical Context: Why Asthma Amplifies Risk

• The coexistence of asthma is the single most important risk factor for fatal food-induced anaphylaxis, particularly with peanut or tree nut allergy. 1, 2
• Asthmatic patients with food allergy are 2-4 times more likely to experience severe or fatal reactions compared to non-asthmatics. 1, 2
• This elevated risk exists regardless of asthma severity, making confirmed food allergy identification critical in all asthmatic patients. 2, 6

Specific Food Additives to Consider

Sulfites: The One Exception

• Sulfiting agents (found in shrimp, dried fruit, processed potatoes, beer, and wine) can precipitate acute asthma symptoms in sulfite-sensitive individuals. 1
• This reaction occurs primarily in patients with more severe underlying asthma and represents a direct respiratory trigger rather than IgE-mediated allergy. 1, 6
• If a patient reports consistent respiratory symptoms after consuming these foods, empiric avoidance of sulfite-containing foods is reasonable. 1

Additives That Do NOT Require Avoidance

• There is no convincing evidence that tartrazine (yellow dye) or monosodium glutamate trigger asthma responses, despite common patient perception. 6

When to Test for Food Allergy in Asthmatic Patients

Children Under 5 Years with Moderate-to-Severe Atopic Dermatitis

• Consider food allergy evaluation for milk, egg, peanut, wheat, and soy if the child has persistent atopic dermatitis despite optimized topical therapy OR has a reliable history of immediate reaction after food ingestion. 1
• This population has up to 37% prevalence of IgE-mediated food allergy. 1

Any Asthmatic Patient with Suspected Food-Triggered Symptoms

• Perform skin prick testing or specific IgE testing when history suggests food allergy, but positive results must be confirmed with oral food challenge for definitive diagnosis. 6
• Widespread testing without clinical suspicion leads to false positives and unnecessary dietary restrictions. 1

Common Pitfalls to Avoid

• Do not recommend empiric food elimination diets based on patient perception that foods worsen asthma—avoidance of specific foods has not been shown to improve asthma even when patients believe foods trigger symptoms. 6
• Do not avoid cross-reactive foods within the same allergen family (e.g., all tree nuts) without individual testing, as clinical cross-reactivity rates vary and many related foods may be safely consumed. 1, 7
• Do not restrict maternal diet during pregnancy or lactation as a strategy for preventing food allergy development in at-risk children. 1
• Do not delay introduction of allergenic foods in infants at risk for food allergy—there is insufficient evidence to support delayed introduction and some evidence favoring early introduction. 1

Management Algorithm for Confirmed Food Allergy in Asthmatics

1. Strict avoidance of documented allergens with careful label reading and awareness of cross-contact during food preparation. 1
2. Prescribe epinephrine autoinjectors and train patient/caregivers on immediate administration at first sign of reaction—delayed epinephrine is associated with fatal outcomes. 3, 4
3. Optimize asthma control with appropriate controller medications, as better asthma control may reduce severity of food-induced reactions. 1
4. Provide nutritional counseling and regular growth monitoring for all children with food allergies to prevent deficiencies from elimination diets. 1
5. Develop written emergency action plan specifying trigger foods, symptoms requiring epinephrine, and emergency contact information. 4