Latest Developments in the Management of Nut Allergies.

PURPOSE OF REVIEW: In this review, we sought to describe the most recent advances in the dietary and medical management of peanut and tree nut allergy, including selective introduction and immunotherapy. RECENT FINDINGS: Dietary updates include changes to labeling laws, improved information sources, and new apps for buying foods in shops and overseas to better protect individuals with nut allergies. There are still issues in the management of nut allergies in schools, such as parents having to resort to packed lunches instead of school meals and patients experiencing bullying. Air travel also poses concern, but additional resources are now available to travelers, and recent evidence suggest limited airborne exposure to nuts. The medical management of anaphylaxis is use of epinephrine; however, this remains underutilized. Needle length and administration devices have been recently debated considering the risk of bone penetration vs subcutaneous administration, and autoinjectors seem to deliver higher peak concentrations than syringes. Selective nut introduction has gained momentum in the last 5 years, demonstrating improved quality of life but with the need for motivated parents for continued consumption and available resources for challenges. Immunotherapy to nuts is also a rapidly developing field, with the balance of efficacy and safety being important considerations in the differing modes of administration. SUMMARY: The management of nut allergies is a rapidly developing field, and dietary and medical management have progressed significantly in the last 5 years. Future research directions include improving safety and efficacy of food immunotherapy and examining patients' goals for therapy and treatment outcomes.

Longitudinal analysis of the effect of water hardness on atopic eczema: evidence for gene-environment interaction.

BACKGROUND: Several studies have identified an association between water hardness and atopic eczema (AE); however, there is a paucity of longitudinal data in early life. OBJECTIVES: To examine whether water hardness is associated with an increased risk of AE and skin barrier dysfunction in infants and to assess effect modification by filaggrin (FLG) loss-of-function variants. METHODS: We performed a longitudinal analysis of data from infants in the Enquiring About Tolerance (EAT) study, who were enrolled at 3 months and followed up until 36 months of age. RESULTS: Of 1303 infants enrolled in the EAT study, 91·3% (n = 1189) attended the final clinic visit and 94·0% (n = 1225) of participants' families completed the 36-month questionnaire. In total, 761 (58·4%) developed AE by 36 months. There was no overall association between exposure to harder (> 257 mg L-1 CaCO3 ) vs. softer (≤ 257 mg L-1 CaCO3 ) water: adjusted hazard ratio (HR) 1·07, 95% confidence interval (CI) 0·92-1·24. However, there was an increased incidence of AE in infants with FLG mutations exposed to hard water (adjusted HR 2·72, 95% CI 2·03-3·66), and statistically significant interactions between hard water plus FLG and both risk of AE (HR 1·80, 95% CI 1·17-2·78) and transepidermal water loss (0·0081 g m-2 h-1 per mg L-1 CaCO3 , 95% CI 0·00028-0·016). CONCLUSIONS: There is evidence of an interaction between water hardness and FLG mutations in the development of infantile AE.

Environmental peanut exposure increases the risk of peanut sensitization in high-risk children.

BACKGROUND: High household peanut consumption is associated with the development of peanut allergy, especially when peanut allergic cases are compared against atopic controls; thus, environmental peanut exposure (EPE) may be a risk factor for peanut sensitization and allergy. In this study, we explored the relationship between EPE and school-age peanut sensitization in a population-based cohort. METHODS: Maternal bed dust was collected postnatally, and EPE was quantified using a polyclonal peanut ELISA. Peanut sensitization was assessed by specific IgE to peanut extract and sIgE to peanut protein component allergens Ara h 1, 2 or 3 ≥ 0.35kU/L (primary peanut sensitization). Initial nested case-control analysis was performed comparing peanut-sensitized cases against high-risk controls (matched for parental atopy) (n = 411) using a conditional regression analysis. This was followed by whole cohort analysis (n = 1878) comparing EPE against peanut sIgE sensitization at ages 4 and 8 years using generalized estimating equations and against primary peanut sensitization at age 8 years using a logistic regression model. Finally, a subgroup analysis was performed comparing the impact of EPE in peanut-sensitized vs egg-sensitized, peanut-tolerant individuals using logistic regression analysis. Levels of EPE were compared between groups using the Mann-Whitney U test. RESULTS: In the nested case-control analysis, a higher level of EPE around birth was associated with peanut-specific IgE sensitization at age 4 years (OR=1.41, 95% CI:1.05-1.90) and primary peanut sensitization at age 8 years (OR=2.11, 95% CI:1.38-3.22) compared against high-risk controls. When the whole BAMSE cohort was assessed, EPE was no longer associated with peanut sensitization; however, on subgroup analysis, EPE was associated with primary peanut sensitization when compared against egg-sensitized peanut-tolerant controls with an adjusted odds ratio of 1.44 per unit EPE (95% CI:1.06-1.94). There was no significant interaction between EPE and FLG loss-of-function mutations, egg sensitization at age 4 years, infantile eczema or parental atopy on peanut sensitization. CONCLUSIONS: Higher levels of environmental exposure to peanut in the first few months of life appear to increase the probability of developing school-age peanut sensitization in atopic children (based on egg sensitization and parental atopy).

EAACI Molecular Allergology User's Guide.

The availability of allergen molecules ('components') from several protein families has advanced our understanding of immunoglobulin E (IgE)-mediated responses and enabled 'component-resolved diagnosis' (CRD). The European Academy of Allergy and Clinical Immunology (EAACI) Molecular Allergology User's Guide (MAUG) provides comprehensive information on important allergens and describes the diagnostic options using CRD. Part A of the EAACI MAUG introduces allergen molecules, families, composition of extracts, databases, and diagnostic IgE, skin, and basophil tests. Singleplex and multiplex IgE assays with components improve both sensitivity for low-abundance allergens and analytical specificity; IgE to individual allergens can yield information on clinical risks and distinguish cross-reactivity from true primary sensitization. Part B discusses the clinical and molecular aspects of IgE-mediated allergies to foods (including nuts, seeds, legumes, fruits, vegetables, cereal grains, milk, egg, meat, fish, and shellfish), inhalants (pollen, mold spores, mites, and animal dander), and Hymenoptera venom. Diagnostic algorithms and short case histories provide useful information for the clinical workup of allergic individuals targeted for CRD. Part C covers protein families containing ubiquitous, highly cross-reactive panallergens from plant (lipid transfer proteins, polcalcins, PR-10, profilins) and animal sources (lipocalins, parvalbumins, serum albumins, tropomyosins) and explains their diagnostic and clinical utility. Part D lists 100 important allergen molecules. In conclusion, IgE-mediated reactions and allergic diseases, including allergic rhinoconjunctivitis, asthma, food reactions, and insect sting reactions, are discussed from a novel molecular perspective. The EAACI MAUG documents the rapid progression of molecular allergology from basic research to its integration into clinical practice, a quantum leap in the management of allergic patients.

Precautionary allergen labelling: perspectives from key stakeholder groups.

Precautionary allergen labelling (PAL) was introduced by the food industry to help manage and communicate the possibility of reaction from the unintended presence of allergens in foods. However, in its current form, PAL is counterproductive for consumers with food allergies. This review aims to summarize the perspectives of all the key stakeholders (including clinicians, patients, food industry and regulators), with the aim of defining common health protection and risk minimization goals. The lack of agreed reference doses has resulted in inconsistent application of PAL by the food industry and in levels of contamination that prompt withdrawal action by enforcement officers. So there is a poor relationship between the presence or absence of PAL and actual reaction risk. This has led to a loss of trust in PAL, reducing the ability of consumers with food allergies to make informed choices. The result has been reduced avoidance, reduced quality of life and increased risk-taking by consumers who often ignore PAL. All contributing stakeholders agree that PAL must reflect actual risk. PAL should be transparent and consistent with rules underpinning decision-making process being communicated clearly to all stakeholders. The use of PAL should indicate the possible, unintended presence of an allergen in a consumed portion of a food product at or above any proposed action level. This will require combined work by all stakeholders to ensure everyone understands the approach and its limitations. Consumers with food allergy then need to be educated to undertake individualized risk assessments in relation to any PAL present.

Dietary management of peanut and tree nut allergy: what exactly should patients avoid?

Peanut and tree nut allergies are the commonest cause of life-threatening food-allergic reactions and significantly affect quality of life in children and their families. Dietary nut avoidance and provision of emergency medication is currently the mainstay of treatment. Nut avoidance has consequences on both quality of life and nutrition. We review the terminology that may cause confusion and lead to unnecessary dietary restrictions. In peanut or tree nut-allergic children, introduction of specific nuts to which the child is not allergic may improve quality of life and should be considered in patients with multiple foods allergies, vegan or ethnic-specific diets, in whom nuts are an important source of protein. Nut-allergic consumers do not just need to avoid foods containing nuts as an ingredient, but also contend with pre-packed foods which frequently have precautionary allergen labelling (PAL) referring to possible nut contamination. Although the published rate of peanut contamination in 'snack' foods with PAL (see Box ) ranges from 0.9-32.4%, peanut contamination in non-snack items with PAL is far less common. We propose that in some peanut-allergic patients (depending on history of reactivity to trace levels of peanut, reaction severity, other medical conditions, willingness to always carry adrenaline, etc.), consideration may be given to allow the consumption of non-snack foods containing PAL following discussion with the patient's (and their family's) specialist. More work is needed to provide consumers with clearer information on the risk of potential nut contamination in pre-packed food. We also draw attention to the change in legislation in December 2014 that require mandatory disclosure of allergens in non-pre-packed foods.

EAACI food allergy and anaphylaxis guidelines: diagnosis and management of food allergy.

Food allergy can result in considerable morbidity, impact negatively on quality of life, and prove costly in terms of medical care. These guidelines have been prepared by the European Academy of Allergy and Clinical Immunology's (EAACI) Guidelines for Food Allergy and Anaphylaxis Group, building on previous EAACI position papers on adverse reaction to foods and three recent systematic reviews on the epidemiology, diagnosis, and management of food allergy, and provide evidence-based recommendations for the diagnosis and management of food allergy. While the primary audience is allergists, this document is relevant for all other healthcare professionals, including primary care physicians, and pediatric and adult specialists, dieticians, pharmacists and paramedics. Our current understanding of the manifestations of food allergy, the role of diagnostic tests, and the effective management of patients of all ages with food allergy is presented. The acute management of non-life-threatening reactions is covered in these guidelines, but for guidance on the emergency management of anaphylaxis, readers are referred to the related EAACI Anaphylaxis Guidelines.

Anaphylaxis: guidelines from the European Academy of Allergy and Clinical Immunology.

Anaphylaxis is a clinical emergency, and all healthcare professionals should be familiar with its recognition and acute and ongoing management. These guidelines have been prepared by the European Academy of Allergy and Clinical Immunology (EAACI) Taskforce on Anaphylaxis. They aim to provide evidence-based recommendations for the recognition, risk factor assessment, and the management of patients who are at risk of, are experiencing, or have experienced anaphylaxis. While the primary audience is allergists, these guidelines are also relevant to all other healthcare professionals. The development of these guidelines has been underpinned by two systematic reviews of the literature, both on the epidemiology and on clinical management of anaphylaxis. Anaphylaxis is a potentially life-threatening condition whose clinical diagnosis is based on recognition of a constellation of presenting features. First-line treatment for anaphylaxis is intramuscular adrenaline. Useful second-line interventions may include removing the trigger where possible, calling for help, correct positioning of the patient, high-flow oxygen, intravenous fluids, inhaled short-acting bronchodilators, and nebulized adrenaline. Discharge arrangements should involve an assessment of the risk of further reactions, a management plan with an anaphylaxis emergency action plan, and, where appropriate, prescribing an adrenaline auto-injector. If an adrenaline auto-injector is prescribed, education on when and how to use the device should be provided. Specialist follow-up is essential to investigate possible triggers, to perform a comprehensive risk assessment, and to prevent future episodes by developing personalized risk reduction strategies including, where possible, commencing allergen immunotherapy. Training for the patient and all caregivers is essential. There are still many gaps in the evidence base for anaphylaxis.

EAACI food allergy and anaphylaxis guidelines. Primary prevention of food allergy.

Food allergy can have significant effects on morbidity and quality of life and can be costly in terms of medical visits and treatments. There is therefore considerable interest in generating efficient approaches that may reduce the risk of developing food allergy. This guideline has been prepared by the European Academy of Allergy and Clinical Immunology's (EAACI) Taskforce on Prevention and is part of the EAACI Guidelines for Food Allergy and Anaphylaxis. It aims to provide evidence-based recommendations for primary prevention of food allergy. A wide range of antenatal, perinatal, neonatal, and childhood strategies were identified and their effectiveness assessed and synthesized in a systematic review. Based on this evidence, families can be provided with evidence-based advice about preventing food allergy, particularly for infants at high risk for development of allergic disease. The advice for all mothers includes a normal diet without restrictions during pregnancy and lactation. For all infants, exclusive breastfeeding is recommended for at least first 4-6 months of life. If breastfeeding is insufficient or not possible, infants at high-risk can be recommended a hypoallergenic formula with a documented preventive effect for the first 4 months. There is no need to avoid introducing complementary foods beyond 4 months, and currently, the evidence does not justify recommendations about either withholding or encouraging exposure to potentially allergenic foods after 4 months once weaning has commenced, irrespective of atopic heredity. There is no evidence to support the use of prebiotics or probiotics for food allergy prevention.

Management of anaphylaxis: a systematic review.

To establish the effectiveness of interventions for the acute and long-term management of anaphylaxis, seven databases were searched for systematic reviews, randomized controlled trials, quasi-randomized controlled trials, controlled clinical trials, controlled before-after studies and interrupted time series and - only in relation to adrenaline - case series investigating the effectiveness of interventions in managing anaphylaxis. Fifty-five studies satisfied the inclusion criteria. We found no robust studies investigating the effectiveness of adrenaline (epinephrine), H1-antihistamines, systemic glucocorticosteroids or methylxanthines to manage anaphylaxis. There was evidence regarding the optimum route, site and dose of administration of adrenaline from trials studying people with a history of anaphylaxis. This suggested that administration of intramuscular adrenaline into the middle of vastus lateralis muscle is the optimum treatment. Furthermore, fatality register studies have suggested that a failure or delay in administration of adrenaline may increase the risk of death. The main long-term management interventions studied were anaphylaxis management plans and allergen-specific immunotherapy. Management plans may reduce the risk of further reactions, but these studies were at high risk of bias. Venom immunotherapy may reduce the incidence of systemic reactions in those with a history of venom-triggered anaphylaxis.

The epidemiology of anaphylaxis in Europe: a systematic review.

BACKGROUND: Anaphylaxis is an acute, potentially fatal, multi-organ system, allergic reaction caused by the release of chemical mediators from mast cells and basophils. Uncertainty exists around epidemiological measures of incidence and prevalence, risk factors, risk of recurrence, and death due to anaphylaxis. This systematic review aimed to (1) understand and describe the epidemiology of anaphylaxis and (2) describe how these characteristics vary by person, place, and time. METHODS: Using a highly sensitive search strategy, we identified systematic reviews of epidemiological studies, descriptive and analytical epidemiological investigations, and studies involving analysis of routine data. RESULTS: Our searches identified a total of 5,843 potentially eligible studies, of which 49 satisfied our inclusion criteria. Of these, three were suitable for pooled estimates of prevalence. The incidence rates for all-cause anaphylaxis ranged from 1.5 to 7.9 per 100,000 person-years. These data indicated that an estimated 0.3% (95% CI 0.1-0.5) of the population experience anaphylaxis at some point in their lives. Food, drugs, stinging insects, and latex were the most commonly identified triggers. CONCLUSIONS: Anaphylaxis is a common problem, affecting an estimated 1 in 300 of the European population at some time in their lives. Future research needs to focus on better understanding of the trends across Europe and identifying those most likely to experience fatal reactions.

Testing children for allergies: why, how, who and when: an updated statement of the European Academy of Allergy and Clinical Immunology (EAACI) Section on Pediatrics and the EAACI-Clemens von Pirquet Foundation.

Allergic diseases are common in childhood and can cause a significant morbidity and impaired quality-of-life of the children and their families. Adequate allergy testing is the prerequisite for optimal care, including allergen avoidance, pharmacotherapy and immunotherapy. Children with persisting or recurrent or severe symptoms suggestive for allergy should undergo an appropriate diagnostic work-up, irrespective of their age. Adequate allergy testing may also allow defining allergic trigger in common symptoms. We provide here evidence-based guidance on when and how to test for allergy in children based on common presenting symptoms suggestive of allergic diseases.

Paediatric oral peanut challenges: a comparison of practice in London and western Switzerland.

BACKGROUND: There are guidelines on how to develop a food challenge protocol, but at present there is no gold standard guidance on method, and separate units produce differing protocols. METHODS: We performed a retrospective analysis of 200 patients' data from the paediatric allergy units in Lausanne and Geneva, Western Switzerland, and St Thomas' Hospital (STH), UK. RESULTS: St Thomas' Hospital has a younger cohort with a lower overall mean spIgE (2.36 kU/l vs. 8.00 kU/l, P = 0.004). The target peanut protein volumes differed: Switzerland 4.4 g vs. STH 8.4 g. Despite this, the dose actually achieved in positive challenges was not significantly different (2.33 g vs. 1.49 g, P = 0.16). 26% of challenges reacted at 4 g or more of peanut protein. CONCLUSIONS: The differences in results highlight how the variation in reasoning behind food challenge alters the outcome. Standardization of food challenges would allow easy comparison between hospitals and geographical areas for research purposes.

Cutaneous lymphocyte antigen and α4ß7 T-lymphocyte responses are associated with peanut allergy and tolerance in children.

BACKGROUND: It is unclear whether the initial route of allergen exposure in early life could influence the subsequent development of allergy, with cutaneous sensitization leading to peanut allergy (PA), and tolerance induced by oral exposure. The skin- and gastrointestinal (GI)-homing markers, cutaneous lymphocyte antigen (CLA) and α4ß7 integrin, are used to determine whether the state of PA correlates with peanut-specific CLA responses, with tolerance associated with predominant α4ß7 responses. METHODS: CLA+ and α4ß7+ memory T cells were isolated and cultured with peanut extract to assess their proliferation. Stimulation indices were compared in peanut allergic and non-allergic (NA) groups, and peanut-specific cytokine production was measured. RESULTS: In peanut allergic patients, peanut-specific proliferation predominates in the skin-homing CLA+ subset, whilst peanut-tolerant groups have a mixed CLA/α4ß7 response (P = 0.008). Comparison with a control food antigen (ovalbumin) showed that these differences are allergen specific. Cytokine responses showed trends towards Th1 skewing in the GI-homing α4ß7+ cells of peanut-tolerant groups and Th2 skewing in the skin-homing CLA+ cells of peanut allergic patients. CONCLUSION: The predominance of the CLA+ response to peanut in peanut allergic patients is consistent with the hypothesis that allergic sensitization occurs through the skin. The predominant α4ß7+ response in peanut-tolerant groups suggests that allergen exposure through the GI tract induces tolerance.

Specific oral tolerance induction in food allergic children: is oral desensitisation more effective than allergen avoidance?: a meta-analysis of published RCTs.

OBJECTIVE: To determine whether specific oral tolerance induction (SOTI) is more effective than avoidance in inducing tolerance in children aged 0-18 years who have immunoglobulin E (IgE)-mediated food allergy. DATA SOURCES: MEDLINE (1950 to July 2009), EMBASE (1980 to July 2009) and all EBM Reviews: Cochrane Database of Systematic Reviews, ACP Journal Club, Database of Abstracts of Reviews of Effects, Cochrane Methodology Register, Health Technology Assessment and NHS Economic Evaluation Database (from start date to November 2008). The online table of contents (November 2003 to July 2009) of the Journal of Allergy and Clinical Immunology, Pediatric Allergy and Immunology and Allergy were also searched, and reference lists of retrieved articles were scrutinised for relevant studies. STUDY SELECTION: Randomised controlled trials (RCT) were included providing they enrolled children with IgE-mediated food allergy diagnosed using the criterion standard tool (double-blind placebo-controlled food challenge) before randomisation and also compared posttreatment tolerance between groups using the criterion standard measures. RESULTS: Three studies met the inclusion criteria, and two proved a statistically significant reduction in endpoint allergy (determined by oral food challenge) after SOTI compared with the control. The meta-analysis of the included studies found a lower RR of allergy after SOTI, but this did not meet statistical significance (0.606783; 95% CI 0.317733 to 1.158791). CONCLUSIONS: SOTI cannot yet be recommended in routine practice as a means to induce tolerance in children with IgE-mediated food allergy. Further research is needed using large, high-quality RCT that investigate a variety of food allergens and assesses the long-term efficacy, safety and cost-effectiveness of SOTI.

Filaggrin loss-of-function mutations are associated with early-onset eczema, eczema severity and transepidermal water loss at 3 months of age.

BACKGROUND: Filaggrin loss-of-function (FLG) mutations are associated with eczema and skin barrier impairment, but it is unclear whether skin barrier impairment precedes phenotypic eczema in FLG mutation carriers. OBJECTIVES: To study the association between FLG mutations, skin barrier impairment and clinical eczema at 3 months of age. METHODS: A total of 88 infants were examined for eczema. Disease severity was determined by the SCORAD eczema severity score. Transepidermal water loss (TEWL) was measured on unaffected forearm skin. Venous blood samples were screened for the four most common FLG mutations found in the U.K. white population (R501X, 2282del4, R2447X and S3247X). Median SCORAD and TEWL measurements in children with and without eczema and FLG mutations were compared. RESULTS: Thirty-three per cent (29/88) of children had clinical eczema. Median SCORAD was 10·6 (range 3·5-31·0). TEWL (g m⁻² h⁻¹) was higher in children with eczema compared with unaffected infants (median TEWL 14·24 vs. 11·24, P < 0·001). Higher TEWL was associated with more severe disease (r = 0·59, P < 0·001, median TEWL, SCORAD < 15, 13·1 vs. 29·6, SCORAD ≥ 15, P = 0·029). Clinically dry skin was associated with higher TEWL, even in the absence of eczema (median TEWL 17·55 vs. 11·08, P = 0·008). Seventeen per cent (15/88) of children carried at least one FLG mutation. FLG mutation carriers were significantly more likely to have clinically dry skin, even in the absence of eczema [odds ratio (OR) 8·50, 95% confidence interval (CI) 1·09-66·58, P = 0·042]. FLG mutation carriers were also more likely to have eczema by 3 months of age (OR 4·26, 95% CI 1·34-13·57, P = 0·014). FLG mutations were significantly associated with higher median TEWL (all children, FLG 'yes' 21·59 vs. FLG 'no' 11·24, P < 0·001), even without clinical eczema (FLG 'yes' 15·99 vs. FLG 'no' 10·82, P = 0·01). CONCLUSIONS: By the age of 3 months, FLG mutations are associated with an eczema phenotype, dry skin and TEWL. The observation that TEWL is elevated in unaffected FLG mutation carriers suggests that skin barrier impairment precedes clinical eczema.

Resource implications and budget impact of managing cow milk allergy in the UK.

AIM: To determine current treatment patterns for infants with cow milk allergy (CMA) and the associated resource implications and budget impact, from the perspective of the UK's National Health Service (NHS). METHODS: A computer-based model was constructed depicting current management of newly-diagnosed infants with CMA derived from patients suffering from this allergy in The Health Improvement Network (THIN) Database. The model spanned a period of 12 months following initial presentation to a general practitioner (GP) and was used to estimate the 12-monthly healthcare cost (at 2006/07 prices) of treating an annual cohort of 18,350 infants from when they initially present to their GP. RESULTS: Patients presenting with a combination of gastrointestinal and atopic symptoms accounted for 59% of all patients. From the initial GP visit for CMA it took a mean 2.2 months to be put on diet, although treatment varied according to presenting symptoms. A total of 60% of all infants were initially treated with soy, 18% with an extensively hydrolysed formula and 3% with an amino acid formula. A mean 9% of patients remained symptomatic on soy and 29% on an extensively hydrolysed formula. The total cost of managing CMA over the first 12 months following initial presentation to a GP was estimated to be £1,381 per patient and £25.6 million for an annual cohort of 18,350 infants. LIMITATIONS: Patients were not randomised to treatment and resource use was not collected prospectively. Nevertheless, 1,000 eligible patients have been included in the analysis, which should be a sufficiently large sample to accurately assess treatment patterns and healthcare resource use in actual clinical practice. The diagnosis of CMA may not be secure in all cases. Nevertheless, patients were diagnosed as having CMA by a clinician and have been managed by their GP as if they had CMA. CONCLUSION: CMA imposes a substantial burden on the NHS. Any strategy that improves healthcare delivery and thereby shortens time to treatment, time to diagnosis and time to symptom resolution should potentially decrease the burden this allergy imposes on the health service and release resources for alternative use.