How to interpret skin prick tests and serum-specific IgE in children and young people with food allergy

Author(s):  
Kathryn Ferris ◽  
Marianne Cowan ◽  
Christine Williams ◽  
Sinead McAteer ◽  
Caoimhe Glancy ◽  
...  

Food allergy is common, it can lead to significant morbidity andnegatively impacts on quality of life; therefore, it is vitally important we get the diagnosis right. However, making the diagnosis can be complex. Clinical history is the most important diagnostic tool and subsequent investigation may help confirm the diagnosis. The investigations available to most paediatric departments are skin prick testing and specific IgE so we will focus on these. Within this article we explore the evidence related to targeted testing and how to interpret these within the clinical context.

Author(s):  
John Puntis

Food allergy is an immune response to food that can be classified as immunoglobulin (Ig)-E and non-IgE mediated. Milk, egg, peanut, tree nuts, and fish are among the most prevalent causes of food allergy. Mild reactions can include itchy rash, watering eyes, and nasal congestion while a severe reaction results in anaphylaxis. A detailed clinical history is essential when making a diagnosis, and skin prick testing and quantitative measurement of food-specific IgE antibodies can be helpful. Cow milk protein allergy causes a plethora of symptoms and frequently resolves spontaneously over the first 2 years of life; diagnosis is based mainly on clinical history. Food challenges have a pivotal role in the diagnosis of food allergy. Introduction of ‘allergic’ foods at 3–6 months alongside continuing breastfeeding may prevent allergy.


2020 ◽  
Vol 2 (1) ◽  
pp. 91-94
Author(s):  
Megan F. Patterson ◽  
Stacy L. Dorris

Food allergy or intolerance is often attributed by patients as the cause of many symptoms unknown to be directly related to food ingestion. For immunoglobulin E (IgE) mediated food allergy, diagnostic modalities are currently limited to the combination of clinical history, evidence of sensitization with food-specific IgE testing and skin-prick testing, and oral food challenge. Many patients find an appeal in the promise of identification of the etiology of their symptoms through alternative food allergy or intolerance diagnostic modalities. These patients may seek guidance from allergists or their general providers as to the legitimacy of these tests or interpretation of results. These tests include food-specific serum IgG or IgG4 testing, flow cytometry to measure the change in leukocyte volume after exposure to food, intradermal or sublingual provocation-neutralization, electrodermal testing, applied kinesiology, hair analysis, and iridology. In addition, there are some unconventional therapeutic modalities for adverse reactions to foods, including rotary diets. None of these have been supported by scientific evidence, and some even carry the risk of severe adverse reactions. It is important that we offer our patients evidence-based, accurate counseling of these unproven modalities by understanding their methods, their paucity of credible scientific support, and their associated risks.


Children ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 497
Author(s):  
Aikaterini Anagnostou

Background: Food allergies are common, affecting 1 in 13 school children in the United States and their prevalence is increasing. Many misconceptions exist with regards to food allergy prevention, diagnosis and management. Objective: The main objective of this review is to address misconceptions with regards to food allergies and discuss the optimal, evidence-based approach for patients who carry this diagnosis. Observations: Common misconceptions in terms of food allergy prevention include beliefs that breastfeeding and delayed introduction of allergenic foods prevent the development of food allergies. In terms of diagnosis, statements such as ‘larger skin prick tests or/and higher levels of food-specific IgE can predict the severity of food-induced allergic reactions’, or ‘Tryptase is always elevated in food-induced anaphylaxis’ are inaccurate. Additionally, egg allergy is not a contraindication for receiving the influenza vaccine, food-allergy related fatalities are rare and peanut oral immunotherapy, despite reported benefits, is not a cure for food allergies. Finally, not all infants with eczema will develop food allergies and epinephrine auto-injectors may unfortunately be both unavailable and underused in food-triggered anaphylaxis. Conclusions and relevance: Healthcare professionals must be familiar with recent evidence in the food allergy field and avoid common misunderstandings that may negatively affect prevention, diagnosis and management of this chronic disease.


2020 ◽  
pp. 4059-4066
Author(s):  
Stephen R. Durham ◽  
Hesham A. Saleh

Allergic rhinitis affects more than 20% of the population of Westernized countries and has a significant impact on quality of life and school/work performance. Important environmental factors include tree and grass pollens (seasonal allergic rhinitis); house dust mite and domestic pets, most often cats (perennial allergic rhinitis); and a variety of occupational exposures (occupational rhinitis). Pathogenesis involves activation of type 2 (Th2) lymphocytes resulting in IgE antibody production and tissue eosinophilia. Immediate symptoms (itching, sneezing, and watery nasal discharge) result from allergen cross-linking adjacent IgE molecules on the surface of mast cells in the nasal mucosa, resulting in the release of histamine and tryptase, and generation of bradykinin. Diagnosis is usually straightforward and based on the history, examination, and (when indicated) the results of skin prick tests and/or serum allergen-specific IgE levels.


2013 ◽  
Vol 8 ◽  
Author(s):  
Gennaro Liccardi ◽  
Gennaro Baldi ◽  
Anna Ciccarelli ◽  
Marina Cutajar ◽  
Maria D’Amato ◽  
...  

Background: Up to now very few data on allergic sensitization to rodent allergens in Western Europe and Italy are available, and there are no information at district level. The aim of this report was to investigate clinical significance and characteristics of allergic sensitization to mouse/rat (M/ Rt) allergens in atopic subjects living in Campania district (Southern Italy). Methods: Allergists from the whole Campania district were required to report the results of skin prick tests of at least 100 consecutive subjects. In 1,477 consecutive outpatients, we selected all subjects with an immediate skin reaction to M/Rt dander. Clinical history including a careful evaluation of the modality of exposure and the results of skin-prick tests (SPTs) were recorded. Results: Fifty seven patients were sensitized to M/Rt dander (5.78%). Two patients were mono-sensitized. Fourteen patients reported indoor conditions suggesting presence of rodents allergens at home. All patients exhibited low-moderate degree of SPT positivity to M/Rt. High frequency of concomitant allergic sensitization to dust mites was found. Conclusions: Our results suggest that the role of allergic sensitization to rodents is not negligible in atopic subjects without occupational exposure living in Campania district area; these values are higher in comparison to those previously found in Naples area. Highly atopic individuals should be tested by SPTs/evaluation of serum specific IgE to rodents in the case they should begin an occupational exposure to M/Rt or keep these animals as pets.


2020 ◽  
Vol 2 (1) ◽  
pp. 119-123
Author(s):  
Amber N. Pepper ◽  
Panida Sriaroon ◽  
Mark C. Glaum

Food additives are natural or synthetic substances added to foods at any stage of production to enhance flavor, texture, appearance, preservation, safety, or other qualities. Common categories include preservatives and antimicrobials, colorings and dyes, flavorings, antioxidants, stabilizers, and emulsifiers. Natural substances rather than synthetics are more likely to cause hypersensitivity. Although rare, food additive hypersensitivity should be suspected in patients with immunoglobulin E (IgE)-mediated reactions to multiple, unrelated foods, especially if the foods are prepared outside of the home or when using commercial products. A complete and thorough history is vital. Skin prick testing and/or specific IgE blood testing to food additives, if available, additive avoidance diets, and blind oral challenges can help establish the diagnosis. Once an allergy to a food additive is confirmed, management involves avoidance and, if necessary, carrying self-injectable epinephrine.


2020 ◽  
Vol 2 (1) ◽  
pp. 35-38
Author(s):  
Tina Banzon ◽  
Donald Y.M. Leung ◽  
Lynda C. Schneider

Atopic dermatitis (AD), characterized by intense pruritus, eczematous lesions, and a relapsing disease course, is a chronic inflammatory skin disease that affects both children and adults. AD often begins in infancy and is associated with atopic diseases in the personal or family history.1 Environmental factors may trigger AD by affecting the skin barrier and by triggering inflammation. The elicitation of T-helper type 2 cytokines further impairs the epidermal barrier and leads to the penetration of irritants and allergens into the epidermis and thereby perpetuating inflammation. The presence of AD and its severity has been shown to positively correlate with risk of developing food allergy (FA). Children with AD are estimated to be six times more likely to develop FA compared with their healthy peers. It has been reported that nearly 40% of children with moderate-to-severe AD have immunoglobulin E (IgE) mediated FA compared with only 6% in the general population. Although analysis of experimental data has linked skin inflammation in AD to FA, with food challenges reproducing symptoms and avoidance diets improving AD, elimination diets are not known to cure AD and may have unfavorable consequences, such as loss of tolerance, which leads to immediate-type allergy, including anaphylaxis, nutritional deficiencies, growth failure, and reduction of quality of life for the patient and family. Exacerbation of AD can be inaccurately attributed to foods. Individuals with AD are often sensitized to foods with positive testing results, however, able to tolerate the food. In light of widespread ordering and commercial availability of serum specific IgE for FA, testing for FA is recommended only if, from a detailed clinical history, immediate-type allergic symptoms occur with ingestion of food, or in infants with AD who do not improve with optimal skin care.


2016 ◽  
Vol 71 (1) ◽  
pp. 68-76
Author(s):  
M. A. Snovskaya ◽  
L. S. Namazova-Baranova ◽  
E. L. Semikina ◽  
S. G. Makarova ◽  
O. V. Kozhevnikova ◽  
...  

Food allergy (FA) is an important health problem which determines lower life quality of a patient and his family. Egg proteins, milk, soy, wheat, and nuts provoke FA more often but any food product may potentially cause allergic reactions. So the aim was to study the age-specific dynamics of antibody response and select the most meaningful IgE production triggers in children with PA. Materials and Methods. The study included 682 children with FA divided into groups according to age: 2−5 months, 6−18 months, 1.5−4 years, 4−10 years, older than 10 years. The IgE levels to cereals, vegetables, bananas, meat, and poultry allergens were measured in blood samples. Results. The age dynamic of IgE-positive responses was detected. The frequency of positive responses was higher in older children. The most significant IgE production triggers for 2−5 months children were allergens of potatoes, pork and cereals (8−14%); for 6−18 month children potatoes (22.7%), buckwheat (19,3%), cereals (10−15%); for 1.5−4 years children ― bananas (29.5%), cereals, carrots and potatoes (19,5−24%); for 4−10 years children ― bananas, carrots and cereals (20−28%); for the senior children ― carrots (47.5%), bananas, cereals and tomatoes (30−36%). Chicken-specific IgE-positive response was minimal for all ages, and meat or poultry specific IgE were observed in 8−15% of patients. Conclusion. Different groups of food allergens provoke sensitization in children during their life. The range of food products with low allergenic activity remains constant in various ages. Age characteristics of IgE production requires differentiated diagnosis approach. 


2018 ◽  
Vol 120 (10) ◽  
pp. 1117-1121
Author(s):  
Mahshid Sirjani ◽  
Raheleh Shokouhi Shoormasti ◽  
Nastaran Sabetkish ◽  
Maryam Ayazi ◽  
Nazanin Khodayari Namini ◽  
...  

AbstractWe aimed to assess the possible relationship between food allergy and two key adipokines – leptin and adiponectin – in children with food allergy. A total of forty patients with definite diagnosis of food allergy according to clinical history and specific IgE (sIgE) for food allergens (group I) were enrolled in this pilot study. The control group (group II) included thirty children with no evidence of allergic symptoms. Serum levels of leptin and adiponectin were measured by ELISA. Meanwhile, sIgE was measured for the eight most common food allergens by the immunoblot method in all participants. The median ages in groups I and II were 18·5 and 23·5 months, respectively. The respective Caesarean section rate was 64·9 and 16·7 % in groups I and II (P<0·001). Serum levels of adiponectin were significantly higher in the patient group compared with controls (24·11 (sd12·14)v. 10·67 (sd12·23) μg/ml,P<0·001), whereas no statistically meaningful difference was detected in serum leptin concentrations (P=0·92). There was a significant inverse relationship between age and adiponectin levels in group I (P=0·002,r–0·479) and group II (P=0·04,r–0·365), and it was more significant in group I. The most common allergens in the patient group were wheat (52·5 %), hazelnut (52·5 %), cow’s milk (50 %) and egg white (30 %). The results of this study suggest an essential link between adiponectin and food allergy that is probably unlikely to be affected by obesity as a confounding factor.


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