Debra de Silva

and 22 more

Background There is substantial interest in allergen-specific immunotherapy in food allergy. We systematically reviewed its efficacy and safety. Methods We searched six bibliographic databases from 1946 to 30 April 2021 for randomised controlled trials about immunotherapy alone or with biologicals in IgE-mediated food allergy confirmed by oral food challenge. We pooled the data using random-effects meta-analysis. Results We included 36 trials with 2,126 participants, mainly children. Oral immunotherapy increased tolerance whilst on therapy for peanut (RR 9.9, 95% CI 4.5. to 21.4, high certainty); cow’s milk (RR 5.7, 1.9 to 16.7, moderate certainty) and hen’s egg allergy (RR 8.9, 4.4 to 18, moderate certainty). The number needed to treat to increase tolerance to a single dose of 300mg or 1000mg peanut protein was 2. In peanut allergy, oral immunotherapy did not increase adverse reactions (RR 1.1, 1.0 to 1.2, low certainty) or severe reactions (RR 1,6, 0.7 to 3.5, low certainty). It may increase adverse reactions in cow’s milk (RR 3.9, 2.1 to 7.5, low certainty) and hen’s egg allergy (RR 7.0, 2.4 to 19.8, moderate certainty), but reactions tended to be mild and gastrointestinal. Epicutaneous immunotherapy increased tolerance whilst on therapy for peanut (RR 2.6, 1.8 to 3.8, moderate certainty). Results were unclear for other allergies and administration routes. Conclusions Oral immunotherapy improves tolerance whilst on therapy and is probably safe in peanut, cow’s milk and hen’s egg allergy. However, our review found little about whether this improves quality of life, is sustained or cost-effective.

Marek Jutel

and 68 more

Ioana Maris

and 26 more

Background: Peanut allergy has a rising prevalence in high-income countries, affecting 0.5–1.4% of children. This study aimed to better understand peanut anaphylaxis in comparison to anaphylaxis to other food triggers in European children and adolescents. Methods: Data was sourced from the European Anaphylaxis Registry via an online questionnaire, after in-depth review of food induced anaphylaxis cases in a tertiary paediatric allergy centre. Results: 3514 cases of food anaphylaxis were reported between July 2007 - March 2018, 56% in patients younger than 18 years. Peanut anaphylaxis was recorded in 459 children and adolescents (85% of all peanut anaphylaxis cases). Previous reactions (42% vs 38%; p=0.001), asthma comorbidity (47% vs 35%; p<0.001), relevant co-factors (29% vs 22%; p=0.004) and biphasic reactions (10% vs 4%; p=0.001) were more commonly reported in peanut anaphylaxis. Most cases were labelled as severe anaphylaxis (Ring&Messmer grade III 65% vs 56% and grade IV 1.1% vs 0.9%; p=0.001). Self-administration of intramuscular adrenaline was low (17% vs 15%), professional adrenaline administration was higher in non-peanut food anaphylaxis (34% vs 26%; p=0.003). Hospitalisation was higher for peanut anaphylaxis (67% vs 54%; p=0.004). Conclusions: The European Anaphylaxis Registry data confirmed peanut as one of the major causes of severe, potentially life-threatening allergic reactions in European children, with some characteristic features e.g. presence of asthma comorbidity and increased rate of biphasic reactions. Usage of intramuscular adrenaline as first line treatment is low and needs to be improved. The Registry, designed as the largest database on anaphylaxis, allows continuous assessment of this condition.

Paul Turner

and 13 more

Background: There is increasing interest in the use of eliciting doses (EDs) to inform allergen risk management. EDs can be estimated from the distribution of threshold doses for allergic subjects undergoing food challenges within a specified population. Estimated ED05 values for cow’s milk (the dose expected to cause objective allergic symptoms in 5% of the milk-allergic population) range from 0.5mg to 13.9mg cow’s milk protein. We undertook a single-dose challenge study to validate a predicted ED05 for cow’s milk of 0.5mg protein. Methods: Participants were recruited from 4 clinical centres. Predetermined criteria were used to identify patients reacting to 0.5mg cow’s milk protein (approximately 0.015ml of fresh cow’s milk). Children over 1 year underwent formal challenge to cow’s milk to confirm clinical reactivity. Results: 172 children (median age 6 (IQR 0.7-11) years, 57% male) were included in this analysis. Twelve (7.0%, 95% CI 3.7-11.9%) children experienced objective symptoms that met the predetermined criteria. One participant had mild anaphylaxis which responded to a single dose of adrenaline, the remainder experienced only mild symptoms with no treatment required. We did not identify any baseline predictors of sensitisation which were associated with objective reactivity to the single-dose challenge using 0.5mg cow’s milk protein. Conclusions: These data support an estimated ED05 for cow’s milk of 0.5mg protein. Values for ED05 above 0.5mg for cow’s milk protein proposed for allergen risk management need to be reviewed.

Debra de Silva

and 25 more

Background This systematic review used the GRADE approach to compile evidence to inform an anaphylaxis guideline from the European Academy of Allergy and Clinical Immunology (EAACI). Methods We searched five bibliographic databases from 1946 to 20 April 2020 for studies about the diagnosis, management and prevention of anaphylaxis. We included 50 studies with 18,449 participants: 29 randomised controlled trials, seven controlled clinical trials, seven consecutive case series and seven case-control studies. Findings were summarised narratively because studies were too heterogeneous to conduct meta-analysis. Results It is unclear whether the NIAID/FAAN criteria or Brighton case definition are valid for immediately diagnosing anaphylaxis due to the very low certainty of evidence. Adrenaline is the cornerstone of first-line emergency management of anaphylaxis but, due to ethical constraints, little robust research has assessed its effectiveness . Newer models of adrenaline autoinjectors may slightly increase the proportion of people correctly using the devices and reduce time to administration. Face-to-face training for laypeople may slightly improve anaphylaxis knowledge and competence in using autoinjectors. Adrenaline prophylaxis prior to snake bite anti-venom may reduce anaphylaxis but the impact of prophylactic corticosteroids and antihistamines is uncertain. There was insufficient evidence about the impact of other anaphylaxis management strategies. Conclusions Anaphylaxis is a potentially life-threatening condition but, due to practical and ethical challenges, there is a paucity of robust evidence about how to diagnose and manage it.