Individually dosed omalizumab: an effective treatment for severe peanut allergy.

BACKGROUND: Treatment with omalizumab has shown a positive effect on food allergies, but no dosages are established. Basophil allergen threshold sensitivity (CD-sens) can be used to objectively measure omalizumab treatment efficacy and correlates with the outcome of double-blind placebo-controlled food challenge to peanut. OBJECTIVE: To evaluate whether individualized omalizumab treatment monitored by CD-sens could be an effective intervention for suppression of allergic reactions to peanut. METHODS: Severely peanut allergic adolescents (n = 23) were treated with omalizumab for 8 weeks, and CD-sens was analysed before and after. Based on whether CD-sens was suppressed after 8 weeks, the patients either were subject to a peanut challenge or received eight more weeks with increased dose of omalizumab, followed by peanut challenge or another 8-week cycle of omalizumab. IgE and IgE-antibodies to peanut and its components were analysed before treatment. RESULTS: After individualized omalizumab treatment (8-24 weeks), all patients continued with an open peanut challenge with no (n = 18) or mild (n = 5) objective allergic symptoms. Patients (n = 15) needing an elevated omalizumab dose (ED) to suppress CD-sens had significantly higher CD-sens values at baseline 1.49 (0.44-20.5) compared to those (n = 8) who managed with normal dose (ND) 0.32 (0.24-5.5) (P < 0.01). Median ratios for Ara h 2 IgE-ab/IgE were significantly higher in the ED group (17%) compared to the ND group (11%). CONCLUSIONS AND CLINICAL RELEVANCE: Individually dosed omalizumab, monitored by CD-sens, is an effective and safe treatment for severe peanut allergy. The ratio of IgE-ab to storage protein Ara h 2/IgE as well as CD-sens to peanut may predict the need of a higher omalizumab dose. Clinical trials numbers: EudraCT; 2012-005625-78, ClinicalTrials.gov; NCT02402231.

Anaphylaxis to foods in a population of adolescents: incidence, characteristics and associated risks.

BACKGROUND: Information about severe reactions to foods in adolescence is limited. OBJECTIVE: To describe reactions to foods, including anaphylaxis, with regard to incidence, characteristics and associated risks, among 16-year-olds (adolescents) in a large, population-based birth cohort. METHODS: Parent-reported questionnaire data from ages 2-3 months, and 1, 2 and 16 years were used (N = 3153). Anaphylaxis at age 16 years was defined per NIAID/FAAN criteria. Immunoglobulin E (IgE) antibodies to 14 common food and inhalant allergens were analysed at ages 4 (n = 2283) and 16 years (n = 2510). Among adolescents with food-related symptoms (FRS) and for whom blood was available (n = 221), 25 additional food allergen extracts or allergen components were analysed. Associations between reactions to foods, and sensitization and allergic multimorbidity were investigated. RESULTS: In the 12 months prior to the 16-year assessment, 8.5% of adolescents had FRS. This included 0.8% (n = 24) adolescents who were classified as having anaphylaxis, yielding an incidence rate of 761/100 000 person-years. One-third of adolescents accessed health care during anaphylaxis. Allergic multimorbidity in infancy, as well as sensitization to foods and airborne allergens at age 4 years, was associated with an increased risk for FRS in adolescence. Peanuts and tree nuts were the most common culprit foods for anaphylaxis, and fruits and vegetables for non-anaphylactic reactions. Adolescents with anaphylaxis were significantly more likely to be sensitized to storage proteins (Ara h 2, Cor a 9, Cor a 14) and to be polysensitized to foods (P < 0.001 vs. non-anaphylactic reactions). CONCLUSIONS AND CLINICAL RELEVANCE: The incidence of food-induced anaphylaxis during adolescence in our population-based birth cohort is higher than previously reported. Adolescents with anaphylaxis differ from adolescents with non-anaphylactic FRS with regard to culprit foods and sensitization. Adolescents with previous anaphylaxis are likely to be polysensitized to foods, particularly tree nut and peanut storage proteins, and which warrants consideration at follow-up.

Recurrent reactions to food among children at paediatric emergency departments: epidemiology of allergic disease.

BACKGROUND: Knowledge about repeated food reactions in paediatric emergency departments (ED) is sparse. OBJECTIVE: To investigate the incidence and potential risk factors for repeated ED visits for food-allergic reactions among children with a prior ED visit due to reactions to food. METHODS: A total of 358 children with ED visits at paediatric hospitals in Stockholm due to reactions to foods during 2007 (index-reaction) were investigated in relation to recurrent reactions until 30 June 2010. Adjusted Cox proportional hazard models were used to compute relative risks (RR) and 95% confidence intervals (CI). RESULTS: A total of 80 children had 116 ED revisits over a period of 873 patient-years, yielding an incidence rate of 9 per 100 patient-years. Known food allergy before the index ED visit in 2007 increased the risk for ED revisits (RR = 2.30, 95% CI 1.35-3.94). Likewise, prescription of adrenaline auto-injector before the index-reaction increased the risk (RR = 2.02, 95% CI 1.17-3.49). Twenty-one percent of the children had more severe reactions at the revisit, 38% less severe and 41% had reactions of comparable severity. However, among 44% of the children with comparable or less severe reaction at revisit, early treatment with adrenaline hampered the classification of change in severity. CONCLUSIONS AND CLINICAL RELEVANCE: Previously known food allergy and prior prescription of adrenaline are significant risk factors for ED revisits among children with a prior ED visit due to reactions to food. Our results indicate that the severity of the index-reaction cannot be used to predict the severity of the relapse.

Anaphylaxis and reactions to foods in children--a population-based case study of emergency department visits.

BACKGROUND: Information about acute reactions to foods among children is limited. OBJECTIVE: To describe the overall incidence of anaphylaxis in a paediatric emergency department (ED) setting and to describe reactions to foods in relation to sex and age, clinical characteristics and management. METHODS: In a review of medical records, children with ED visits at any of three paediatric hospitals in Stockholm County during 2007 were targeted. Inclusion criteria were any adverse reaction to foods or anaphylaxis. RESULTS: 383 children fulfilled the inclusion criteria of which 371 had had reactions to foods. The incidence of anaphylaxis was 32 per 100 000 person years irrespective of cause and food was involved in 92%. Tree nuts, particular cashew, and peanut were the most common eliciting foods, and in children under 3 years, reactions to these two food allergens were as common as reactions to milk and egg. Pollen-allergic children seemed to be admitted due to food-induced anaphylaxis more often during the deciduous tree pollen season compared with the rest of the year (P = 0.015). Symptoms from the lower airways occurred in 49% of children with anaphylaxis but without underlying asthma compared with 72% of children with anaphylaxis and asthma, P < 0.01. CONCLUSIONS AND CLINICAL RELEVANCE: Reactions to peanut and tree nuts are as common as reactions to milk and egg in early life. Concomitant exposure to airborne allergens seems to increase the risk of anaphylaxis to foods. Among children with anaphylaxis, wheeze is prevalent even in children without asthma diagnosis.