The Effect of Wheat Allergy on the Course of Atopic Eczema in Patients over 14 Years of Age

Skin gluten-related disorders: new and old cutaneous manifestations to be considered

The term gluten-related disorders (GRD) refer to a spectrum of different clinical manifestations triggered by the ingestion of gluten in genetically susceptible individuals, including coeliac disease (CD), wheat allergy and non-celiac gluten sensitivity (NCGS). GRD are characterized by a large variety of clinical presentations with both intestinal and extra-intestinal manifestations. The latter may affect almost every organ of the body, including the skin. Besides the well-known association between CD and dermatitis herpetiformis, considered as the cutaneous specific manifestation of CD, many other muco-cutaneous disorders have been associated to GRD. In this review, we analyzed the main features of dermatological diseases with a proven association with GRD and those that improve after a gluten-free diet, focusing on the newly described cutaneous manifestations associated with NCGS. Our main hypothesis is that a "cutaneous-gluten sensitivity," as specific cutaneous manifestation of NCGS, may exist and could represent a diagnostic marker of NCGS.

When Foods Cause Itch: Clinical Characteristics, Pathophysiology, and Recommendations for Food-Induced Skin and Mucosal Pruritus

Itch occurs in various dermatologic and systemic conditions. Many patients report that certain foods instigate itch, although there is limited published information in dermatology on food-induced pruritus. In addition, itch severity is rarely mentioned. Food can induce pruritus through either ingestion or direct contact with skin or mucosal membranes. The most common type of itch provoked by food is acute urticaria, often through the classical immunoglobulin E (IgE)-mediated pathway. Other mechanisms include non-IgE-mediated, mixed (IgE-mediated and non-IgE-mediated), T-cell-mediated, and nonimmune reactions. For patients presenting with urticaria, generalized pruritus, oral pruritus, or dermatitis, a thorough history is warranted, and possible food associations should be considered and assessed. Although any food seems to have the potential to elicit an immune response, certain foods are especially immunogenic. Treatment includes avoidance of the trigger and symptom management. Careful consideration should be used as to avoid unnecessarily restrictive elimination diets.

Dietary Elimination for the Treatment of Atopic Dermatitis: A Systematic Review and Meta-Analysis

BACKGROUND

The influence of diet on atopic dermatitis (AD) is complex, and the use of dietary elimination as a treatment has conflicting views.

OBJECTIVE

To systematically review the benefits and harms of dietary elimination for the treatment of AD.

METHODS

We searched MEDLINE, Embase, AMED, PsycINFO, and the Cochrane Central Register of Controlled Trials from inception to January 18, 2022, without language restrictions, for randomized controlled trials (RCTs) and observational studies comparing dietary elimination and no dietary elimination for the treatment of AD. We conducted random-effects meta-analyses of eczema outcomes. We used the grading of recommendations, assessment, development, and evaluation approach to assess certainty of evidence (CRD42021237953).

RESULTS

Ten RCT (n = 599; baseline median of study mean age, 1.5 years; median of study mean SCOring Atopic Dermatitis index, 20.7, range, 3.5-37.6) were included in the meta-analysis. Compared with no dietary elimination, low-certainty evidence showed that dietary elimination may slightly improve eczema severity (50% with vs 41% without dietary elimination improved the SCOring Atopic Dermatitis index by a minimally important difference of 8.7 points, risk difference of 9% [95% CI, 0-17]), pruritus (daytime itch score [range, 0-3] mean difference, -0.21 [95% CI, -0.57 to 0.15]), and sleeplessness (sleeplessness score [range, 0-3] mean difference, -0.47 [95% CI, -0.80 to -0.13]). There were no credible subgroup differences based on elimination strategy (empiric vs guided by testing) or food-specific sensitization. Insufficient data addressed harms of elimination diets among included RCTs, although indirect evidence suggests that elimination diets may increase the risk for developing IgE-mediated food allergy.

CONCLUSIONS

Dietary elimination may lead to a slight, potentially unimportant improvement in eczema severity, pruritus, and sleeplessness in patients with mild to moderate AD. This must be balanced against potential risks for indiscriminate elimination diets including developing IgE-mediated food allergy and withholding more effective treatment options for AD.

When Foods Cause Itch: Clinical Characteristics, Pathophysiology, and Recommendations for Food-Induced Skin and Mucosal Pruritus

ABSTRACT

Itch occurs in various dermatologic and systemic conditions. Many patients report that certain foods instigate itch, although there is limited published information in dermatology on food-induced pruritus. In addition, itch severity is rarely mentioned. Food can induce pruritus through either ingestion or direct contact with skin or mucosal membranes. The most common type of itch provoked by food is acute urticaria, often through the classical immunoglobulin E (IgE)-mediated pathway. Other mechanisms include non-IgE-mediated, mixed (IgE-mediated and non-IgE-mediated), T-cell-mediated, and nonimmune reactions. For patients presenting with urticaria, generalized pruritus, oral pruritus, or dermatitis, a thorough history is warranted, and possible food associations should be considered and assessed. Although any food seems to have the potential to elicit an immune response, certain foods are especially immunogenic. Treatment includes avoidance of the trigger and symptom management. Careful consideration should be used as to avoid unnecessarily restrictive elimination diets.

Atopic Dermatitis and Food Allergy: Best Practices and Knowledge Gaps-A Work Group Report from the AAAAI Allergic Skin Diseases Committee and Leadership Institute Project

Allergists are often asked to evaluate children with atopic dermatitis (AD) for allergen triggers to disease. Testing, particularly for food triggers, often leads to elimination diets in an effort to improve AD control. However, the dual exposure hypothesis suggests that oral tolerance to food antigens is promoted through high-dose oral exposure, where sensitization occurs through lower dose cutaneous exposure. This suggests that strict elimination diets may pose some risks in children with AD. In addition, emerging evidence suggests an important role of skin inflammation in further allergic disease and the importance of dietary exposure to maintain oral tolerance. This work group report reviews current guidelines-based management for children with moderate-to-severe AD, the evidence for current recommendations for the evaluation and management of these children, provides a nuanced examination of these studies, and addresses current knowledge gaps in the care of these children.

The association between atopic dermatitis and food allergy in adults

PURPOSE OF REVIEW

We conducted a systematic literature search for studies investigating the link between atopic dermatitis and food sensitization or clinically significant allergy (FA) in adults, to assess the strength of the association between the two diseases in both general and selected populations.

RECENT FINDINGS

Around 10% of adults with FA have concomitant atopic dermatitis at the population level. Adult atopic dermatitis patients show much higher rates of sensitization to foods than healthy individuals, in particular to food proteins cross-reactive with airborne allergens, rather than the food allergens that typically predominate amongst children with atopic dermatitis. When food challenges have been performed, rather than relying on questionnaire information and specific IgE testing alone, they often do not confirm eczematous reactions. Only half of patients who have challenge-proven FA improve on a strict elimination diet.

SUMMARY

Challenge-proven FA in adults with atopic dermatitis is uncommon. The incidence of new-onset FA in adult atopic dermatitis patients is currently unknown, as are the main routes of sensitization. There is increasing evidence from studies in infants that sensitization to food protein can occur across the skin barrier, in particular in the presence of eczematous skin inflammation. Carefully conducted large longitudinal studies amongst adults that take into account skin barrier function and genetics are required.