Food as a Trigger for Eczema (Atopic Dermatitis)
Food can trigger or worsen eczema (atopic dermatitis) in some patients, particularly in children with moderate to severe disease, but this occurs much less frequently than commonly believed. 1, 2
Prevalence and Clinical Significance
- Food allergies are present in approximately 35% of children with moderate to severe atopic dermatitis, but are much less common in adults with the condition 1, 2
- The presence of severe eczema within the first 6 months of life is associated with an increased risk of developing food allergies, particularly to peanut, milk, and egg 1
- In children, milk, egg, and peanut account for the majority of allergic reactions, while in adults, peanut, tree nuts, and seafood are more common triggers 2
Mechanisms of Food-Induced Eczema
- Food-induced eczema reactions can occur through:
- Eczematous flares erroneously attributed to foods are often actually triggered by other factors such as irritants, humidity changes, or bacterial skin infections 1
Diagnosis of Food-Induced Eczema
When to Suspect Food as a Trigger
- Consider food allergy testing when: 2
- A child under 5 years has moderate to severe atopic dermatitis that persists despite optimized management
- There is a reliable history of immediate allergic reaction after ingestion of a specific food
- Symptoms consistently appear after consuming certain foods 1
Diagnostic Approach
- A detailed medical history and food diary recording symptoms and intake can help identify potential food triggers 1
- Diagnostic methods include: 2
- Skin prick testing (SPT)
- Food-specific IgE levels measured in serum
- Oral food challenges (gold standard)
- Positive allergy tests alone are insufficient for diagnosis as they often reflect sensitization but have poor correlation with clinical allergic responses 2
- Elimination diets should NOT be initiated based solely on the presence of atopic dermatitis or a suspicious history 1
Management Recommendations
For Patients WITH Documented Food Allergy
- For individuals with documented food allergy and atopic dermatitis, avoidance of specific allergen(s) is recommended 1
- Nutritional counseling and regular growth monitoring are essential for all children with food allergies to prevent nutritional deficiencies 1
- An elimination diet should be followed by a physician-supervised oral food challenge to confirm the relationship between the food and eczema symptoms 1, 3
For Patients WITHOUT Documented Food Allergy
- In individuals without documented food allergy, avoiding potentially allergenic foods is NOT recommended as a means of managing atopic dermatitis 1
- Unnecessary food avoidance could lead to nutritional deficiencies and growth deficits without any clinical benefit 1
- Focus should be on conventional eczema management with proper skin care and topical therapies 1
Common Pitfalls to Avoid
- Overestimation of food allergy prevalence: Up to 35% of individuals believe they have food allergy, while actual prevalence confirmed by oral food challenge is only about 3.5% 1
- Multiple dietary restrictions or long-term dietary avoidance should only be undertaken with documented, clinically relevant food allergies 1
- Excessively restrictive diets, especially in children, have led to weight loss, poor growth, calcium deficiency, hypovitaminosis, and kwashiorkor 1, 4
- A retrospective study showed that 84-93% of foods avoided by children with atopic dermatitis could actually be safely reintroduced and tolerated after proper testing 1, 4
Conclusion
While food can trigger eczema flares in some patients, particularly children with moderate to severe disease, this is much less common than generally perceived. Proper diagnosis through medical history, allergy testing, and supervised food challenges is essential before implementing any dietary restrictions. For most patients with atopic dermatitis, effective treatment centers on good skin care and appropriate topical therapies rather than dietary manipulation.