Allergy tests for the diagnosis of culprit allergens in eosinophilic esophagitis: A systematic review. To the Editor,Eosinophilic esophagitis (EoE) is a chronic inflammatory disease with esophageal dysfunction and marked eosinophil-predominant infiltration of the esophagus and a clinicopathologic diagnosis (1,2). Dietary interventions have confirmed the etiological role of food allergens and their combination with topical glucocorticoids is the standard treatment of EoE (1). Three different dietary approaches are usually practiced; an elemental formula diet, “empiric” food eliminations diets (e.g. the 6-FED) and diets based on multimodality allergy testing(1). Skin prick tests (SPT), serum specific (s)IgE, atopy patch tests (APT), but also serum specific (s)IgG4 have been used as allergy diagnostic tools for such diets(1).Elimination diets can serve as the first step to identify the culprit antigens in EoE; after symptoms’ remission foods can be sequentially reintroduced and food triggers can be defined clinicopathologically (1,2). In the present systematic review, the outcomes of a food-reintroduction diagnostic approach served as comparator to the results of allergy tests serving as diagnostic tools of the EoE food triggers. Our aim was to review the literature on the diagnostic value of allergy tests used in everyday practice.The detailed methods of the present systematic review are reported in the published protocol (3). The evidence search and selection process are presented in Figure 1. Fourteen studies fulfilling the quality assessment criteria were included in the review; their characteristics are summarized in Table 1 (references in the supplement). The Risk-of-Bias ratings are shown in Table S1. The studies were assessing complete data of 453 EoE patients. Biopsies were used for re-evaluation in all studies, and as the main criterion of EoE remission in most of the studies.The positive predictive value (PPV) of allergy tests is reported in Table S2. It is deduced by the percentage of allergy tests that have correctly predicted the culprit allergen out of the total number of allergy tests resulting positive. The percentage of patients who responded to treatment was calculated by dividing the number of patients who presented EoE remission after food elimination diets based on positive allergy tests, out of the total number of patients following such diets. Reviewed studies have offered either, or both, of these data.Studies have followed a protocol with a single allergy test, or with the combination of two (SPT+sIgE, SPT+APT), or three. Most single-allergy-test studies have reported PPVs lower than 50%. PPV was better for combined tests; PPV of SPT+APT combination was 67.1%, with 65-88.3% of patients presenting symptom amelioration after following a relevant elimination diet. A study combining SPT+APT+sIgE reported symptoms’ improvement in 67% of the patients.The effectiveness of amino-acid-based elemental diet is approximately 90%, while 6-FED shows a 72.1% effectiveness (4) . The empiric elimination of cow’s milk or dairies is a slightly less-effective strategy. According to our review’s outcomes, allergy-test-driven elimination diets have a maximum efficacy of 66-88.3%, so following them is not superior to empirical diets. The decision to follow any of these options, or alternatively a 4-FED or 2-FED, is individualized according to what best fits to patient’s lifestyle.Esophageal prick testing (EPT) performed with food extracts directly on the esophageal lining is a new diagnostic method offering the advantage to examine the local esophageal response to dietary triggers, that might be completely different to IgE-detection with the usual allergy tests (5). Ex vivo food antigen stimulation method, using stimulation of esophageal biopsies with food extracts is another promising alternative (6).Concluding, although the use of food specific IgE-detection and the performance of APT do not seem useful for selecting which food should be eliminated, it is a fact that personalized elimination of different foods in each patient is highly advised.

Immune modulation is a key therapeutic tool for allergic diseases and asthma. It can be achieved in an antigen-specific way via allergen immunotherapy (AIT) or in endotype-driven approach using biologicals that target the major pathways of the type 2 (T2) immune response: IgE, IL-5 and IL-4/IL-13. COVID-19 vaccine provides an excellent opportunity to tackle the global pandemics and is currently being applied in an accelerated rhythm worldwide. It works as well through immune modulation. Thus, as there is an obvious interference between these treatment modalities recommendations on how they should be applied in sequence are expected. The European Academy of Allergy and Clinical Immunology (EAACI) gathered an outstanding expert panel under its Research and Outreach Committee (ROC). This expert panel was called to evaluate the evidence and formulate recommendation on the administration of COVID-19 vaccine in patients with allergic diseases and asthma receiving AIT or biologicals. The panel also formulated recommendations for COVID-19 vaccine in association with biologicals targeting the type 1 or type 3 immune response. In formulating recommendations, the panel evaluated the mechanisms of COVID-19 infection, of COVID-19 vaccine, of AIT and of biologicals and considered the data published for other anti-infectious vaccines administered concurrently with AIT or biologicals.

Sustained milk consumption after 2 years post-Milk Epicutaneous therapy for Eosinophilic EsophagitisJonathan M. Spergel, MD, PhD1,2; Amanda B. Muir, MD2,3; Chris A. Liacouras, MD2,3;Deirdre Burke1, CRA; Megan O. Lewis, MSN, RN, CPNP1; Terri Brown-Whitehorn, MD1,2, Antonella Cianferoni, MD, PhD1,21Division of Allergy and Immunology, The Children’s Hospital of Philadelphia, PA, USA, 2Department of Pediatrics, The Perelman School of Medicine at University of Pennsylvania, Philadelphia, PA, USA, 3Division of Gastroenterology, Hepatology, and Nutrition, The Children’s Hospital of Philadelphia, PA, USAAuthor contribution:JMS-study design, writing manuscript, interpreting data; ABM-writing manuscript, study visits, data interpretation; CAL-writing manuscript, study design, interpreting data; DB-writing manuscript, regulatory coordinator, coordination and collection of data, study visits; MOL-writing manuscript, collection of data, study visits; TBW-writing manuscript, collection of data and study visits, AC-interpreting data, collection of data, study visits, regulatory itemsTo the Editor:Eosinophilic Esophagitis (EoE) is an allergic disease of the esophagus without any curative therapy. Typical symptoms of EoE are feeding difficulties, vomiting, abdominal pain and dysphagia and vary by age, with a diagnosis confirmed on esophageal biopsy with> 15 eosinophils/high power field (eos/hpf).1 The two treatment options for pediatric EoE2 are: 1) topical swallowed steroids, which is effective in inducing EoE remission in 50-90% of patients, depending on the dose, formulation and medication used; 2) dietary elimination of the causative allergen/s which is effective in 50-70% of patients with selective food elimination, and 95% with elemental diets3. Cow’s milk (CM) is the most common food allergen causing disease in up to 65% of patients.4 When either treatment is discontinued, inflammation and symptoms recur.3Epicutaneous immunotherapy (EPIT) is an investigational immunotherapy using low dose allergen exposure through the skin to induce desensitization. In the randomized controlled clinical trial,Study of Efficacy and Safety of Viaskin® Milk for CM-induced EoE (SMILEE Study) , 20 pediatric participants with CM-induced EoE were randomized to receive EPIT with Viaskin® Milk (n=15) or placebo (n=5)(details in appendix). After CM-induced EoE was confirmed, EPIT therapy was applied daily for 9 months during a CM-free period, followed by CM-containing diet for 2 months (Figure 1). At 11 months, subjects completed an upper endoscopy with biopsy to evaluate tissue eosinophilia as the primary endpoint. In the pre-defined per-protocol population (7 patients-Viaskin® Milk, 2 patients- placebo), Viaskin® Milk treated subjects had a lower number of eosinophils/high power field (eos/hpf) on biopsy (25.57 ± 31.19) compared to placebo (95 ± 63.64). After the blinded phase, 19 subjects were eligible to enroll in the open-label extension (additional 11 months of therapy) and had repeat endoscopy and biopsy. At the end of the open-label phase, 6/19 subjects had < 6 eos/hpf (32% response rate); 3/19 subjects had 7-14 eos/hpf for total response rate of 47%.5As part of routine clinical care, we continue to follow all 19 subjects who completed the open-label extension (currently 2 years after the end of Viaskin® Milk therapy) to understand whether CM continued in their diet without symptoms. Four of 5 subjects who had <6 eos/hpf after milk introduction were able to continue with approximately 2 servings of CM/day without any symptoms (Table 1). One of these patients had a clinically indicated endoscopy and biopsy that had 0 eosinophils. Two subjects, who had 6-14 eos/hpf during the study, continued to tolerate CM, including one subject who continued to have 6-14 eos/hpf on repeat endoscopy. In addition, 4 subjects who had significant symptoms ingesting CM and had > 15 eos/hpf during the initial SMILEE study were able to add CM back into their diet without having symptoms, as either baked CM (n=2) or regular CM with concomitant swallowed steroids therapy (n=2).The follow-up of this pilot study for the use of EPIT for milk-induced EoE suggests that the treatment effect can persist for 2 years after stopping therapy; six out of 7 patients in the responder and partial responder groups remain completely symptom-free while consuming an average of 2 servings/day of CM. In contrast to the current therapies of diet elimination or swallowed topical steroids where symptoms return when therapy is stopped, EPIT has demonstrated a persistent effectiveness. These findings align with EPIT’s proposed mechanism of action, by directly targeting and reprogramming the immune response to allergen.3 EPIT may induce true tolerance, as is observed in murine models, where Foxp3(+) CD25(+) CD4(+) T regulatory cells are induced and can transfer tolerance.6 Further longer-term studies are needed to examine this possibility and confirm these unique findings.Reference:1. Spergel JM, Dellon ES, Liacouras CA, et al. Summary of the updated international consensus diagnostic criteria for eosinophilic esophagitis: AGREE conference. Ann Allergy Asthma Immunol.2018;121:281-284.2. Spergel JM, Brown-Whitehorn TA, Muir A, Liacouras CA. Medical algorithm: Diagnosis and treatment of eosinophilic esophagitis in children. Allergy. 2020;75:1522-1524.3. Nhu QM, Aceves SS. Medical and dietary management of eosinophilic esophagitis. Ann Allergy Asthma Immunol.2018;121:156-161.4. Kagalwalla AF, Amsden K, Shah A, et al. Cow’s milk elimination: a novel dietary approach to treat eosinophilic esophagitis.J Pediatr Gastroenterol Nutr. 2012;55:711-716.5. Spergel JM, Elci OU, Muir AB, et al. Efficacy of Epicutaneous Immunotherapy in Children With Milk-Induced Eosinophilic Esophagitis. Clin Gastroenterol Hepatol. 2020;18:328-336 e327.6. Dioszeghy V, Mondoulet L, Dhelft V, et al. The regulatory T cells induction by epicutaneous immunotherapy is sustained and mediates long-term protection from eosinophilic disorders in peanut-sensitized mice. Clin Exp Allergy. 2014;44:867-881.Sincerely,Jonathan M. Spergel, MD, PhD1,2; Amanda B. Muir, MD2,3; Chris A. Liacouras, MD2,3;Deirdre Burke1, CRA; Megan O. Lewis, MSN, RN, CPNP1; Terri Brown-Whitehorn, MD1,2, Antonella Cianferoni, MD, PhD1,21Division of Allergy and Immunology, The Children’s Hospital of Philadelphia, PA, USA, 2Department of Pediatrics, The Perelman School of Medicine at University of Pennsylvania, Philadelphia, PA, USA, 3Division of Gastroenterology, Hepatology, and Nutrition, The Children’s Hospital of Philadelphia, PA, USAFunding Sources: The Children’s Hospital of Philadelphia Eosinophilic Esophagitis Family FundAcknowledgements: JMS, CAL, TBW and MOL are consultants for DBV Technology.Correspondence: Jonathan M. Spergel MD, PhDThe Children’s Hospital of PhiladelphiaDivision of Allergy and ImmunologyWood Bldg 3352D3401 Civic Center Blvd,Philadelphia, PA 19104Email: [email protected]: 1-215-590-2549Table 1

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), also known as COVID-19, is a new strain of coronavirus that has not been previously identified in humans. SARS-CoV-2 is recognized as a highly contagious respiratory virus with severe morbidity and mortality, especially in vulnerable populations. Being a novel disease, everyone is susceptible, there are no vaccine and no treatment. To contain the spread of the disease, health authorities throughout the world have restricted the social interactions of individuals in various degrees. Allergists like other physicians are faced with the challenge of providing care for their patients, while protecting themselves and patients from getting infected, with strategies that are in continuous evolution as States work through the different stages of social distance. Allergist provides care for patients with the most common noncommunicable disease in the world: asthma, allergic rhinitis, food allergy, venom allergy, drug allergy atopic dermatitis, and urticarial. Some of these diseases are not only considered risk factors for severe reactions but also have symptoms like cough and sneezing that are in differential diagnosis with COVID-19, and as we move forward may prevent allergy patient from working, go to school or access medical services that increasingly are allowing only asymptomatic patients. In this review, we will outline how to take care safety of different allergic patients during the pandemic.