The role of the atopy patch test in the diagnostic work-up of non-IgE gastrointestinal food allergy in children: a systematic review.

The "Atopy Patch Test" (APT) has been proposed as a diagnostic tool for food allergies (FA), especially in children with FA-related gastrointestinal symptoms. However, its diagnostic accuracy is debated, and its usefulness is controversial. The aim of this systematic review was to evaluate the APT diagnostic accuracy compared with the diagnostic gold standard, i.e., the oral food challenge (OFC), in children affected by non-IgE mediated gastrointestinal food allergies, including the evaluation in milk allergic subgroup. Both classical non-IgE mediated clinical pictures and food induced motility disorders (FPIMD) were considered. The search was conducted in PubMed and Scopus from January 2000 to June 2022 by two independent researchers. The patient, intervention, comparators, outcome, and study design approach (PICOS) format was used for developing key questions, to address the APT diagnostic accuracy compared with the oral food challenge (OFC). The quality of the studies was assessed by the QUADAS-2 system. The meta-analysis was performed to calculate the pooled sensitivity, specificity, DOR (diagnostic odds ratio), PLR (positive likelihood ratio), and NLR (negative likelihood ratio) with their 95% confidence intervals (CI). Out of the 457 citations initially identified via the search (196 on PubMed and 261 on Scopus), 37 advanced to full-text screening, and 16 studies were identified to be included in the systematic review. Reference lists from relevant retrievals were searched, and one additional article was added. Finally, 17 studies were included in the systematic review. The analysis showed that APT has a high specificity of 94% (95%CI: 0.88-0.97) in the group of patients affected by FPIMD. Data showed a high pooled specificity of 96% (95% CI: 0.89-0.98) and the highest accuracy of APT in patients affected by cow's milk allergy (AUC = 0.93).      Conclusion: APT is effective in identifying causative food in children with food-induced motility disorders.  What is Known: • Atopy patch test could be a useful diagnostic test for diagnosing food allergy, especially in children with food allergy-related gastrointestinal symptoms. What is New: • Atopy patch test may be a useful tool in diagnosing non IgE food allergy, especially in children with food-induced gastrointestinal motility disorders and cow's milk allergy.

Summation anaphylaxis: A challenging diagnosis.

Anaphylaxis is the most severe of allergic reactions. The most frequent triggers of anaphylaxis in childhood are food, insect venom, drugs, exercise, etc. In some cases, the presence of more than one trigger is necessary for the allergic reaction, while one trigger alone is tolerated. This rare condition is called summation anaphylaxis (SA). Food-dependent exercise-induced anaphylaxis is the most well-known SA. However, SA may also occur with the association between food and/or exercise plus one or more of the following other cofactors, such as drugs, especially non-steroidal anti-inflammatory (NSAID), alcohol, infections, temperature variation, and menstrual cycle. SA can explain some cases of idiopathic anaphylaxis, as well as cases of an apparent breakdown in a previously acquired tolerance for food, or finally, when faced with a suggestive clinical history of food allergy or exercise anaphylaxis and the provocation test is negative. In these situations, a more careful clinical history looking for other cofactors is necessary.

Non-IgE- or Mixed IgE/Non-IgE-Mediated Gastrointestinal Food Allergies in the First Years of Life: Old and New Tools for Diagnosis.

non-IgE and mixed gastrointestinal food allergies present various specific, well-characterized clinical pictures such as food protein-induced allergic proctocolitis, food protein-induced enterocolitis and food protein-induced enteropathy syndrome as well as eosinophilic gastrointestinal disorders such as eosinophilic esophagitis, allergic eosinophilic gastroenteritis and eosinophilic colitis. The aim of this article is to provide an updated review of their different clinical presentations, to suggest a correct approach to their diagnosis and to discuss the usefulness of both old and new diagnostic tools, including fecal biomarkers, atopy patch tests, endoscopy, specific IgG and IgG4 testing, allergen-specific lymphocyte stimulation test (ALST) and clinical score (CoMiss).

COVID-19 and food allergy in children.

In children with food allergy the visits should be limited to those that are unequivocally needed on clinical basis. Food challenge can be performed in selected situations, taking a more detailed history to make sure that patients provide whatever information we need. The maintenance of a safe diet can be hampered by several factors. Nutritional supplementation may be necessary.