Prevalence of Intolerance to Amines and Salicylates in Individuals with Atopic Dermatitis: A Systematic Review and Meta-Analysis

Background/Objectives:
Elimination diets targeting amines and salicylates have been used since the 1980s to diagnose pharmacological food intolerance in individuals with atopic dermatitis (eczema), yet supporting evidence regarding relevance is limited. To our knowledge, this systematic review with meta-analysis is the first to examine the prevalence and association between atopic dermatitis flares and amine intolerance (including histamine intolerance) and salicylate intolerance in individuals with atopic dermatitis.

Methods:
Following the PRISMA guidelines, searches of PubMed, Embase, CINAHL, and Cochrane were conducted. Included studies involved children and adults with atopic dermatitis who underwent dietary elimination and double-blind placebo-controlled challenges involving histamine, other amines, or salicylates. Risk of bias was assessed using the Joanna Briggs Institute Checklist for Prevalence Studies. Meta-analysis of the prevalence of atopic dermatitis flare by food chemical type was performed using a random effects model in Stata/MP, version 16.1 for Windows. Heterogeneity was assessed using the I2 statistic and Cochrane’s Q test.

Results:
A total of 2323 titles and abstracts were screened, with 46 full-text articles evaluated independently by two reviewers, resulting in the inclusion of four prevalence studies involving 188 participants. Meta-analysis of two trials showed histamine intolerance prevalence at 31% [95% CI, 20–41%] with no heterogeneity (I2 = 0.01%). Two trials showed amine intolerance prevalence at 32% [95% CI, 16–48%] with moderate heterogeneity (I2 = 34.91%). Two trials showed salicylate intolerance prevalence at 53% [95% CI, 44–62%] with no heterogeneity (I2 = 0.00%).

Conclusions:
This review suggests there may be low-certainty evidence linking intolerance to histamine, amines, and salicylates to atopic dermatitis flare in a substantial proportion of individuals with atopic dermatitis. Further, well-designed studies are needed to confirm these findings and clarify the role of pharmacological food intolerance in atopic dermatitis.