Åsa Strinnholm

Experiences of Double-Blind, Placebo-Controlled Food Challenges (DBPCFC): a qualitative analysis of mothers’ experiences

Fear and anxiety are recurring problems for parents of food-allergic children. However, no study has described parents’ experiences of introducing food to their children after double-blind provocation. Therefore the aim of this study was to investigate mothers’ experiences during their child’s negative Double-Blind, Placebo-Controlled Food Challenge (DBPCFC) and the following reintroduction of food. Eight mothers were interviewed and a qualitative content analysis displayed two themes and six subthemes. The first theme, ‘living with fear of the unknown’, included the subthemes of ‘fear of losing control’, ‘having faith even though fear prevails’, ‘reintroducing despite fear’ and ‘fear of causing harm’. In the second theme, the mothers described the challenging process of ‘re-evaluating earlier experiences’ through the sub-themes of ‘daring to take new challenges’ and ‘refraining from new challenges’. Our study indicates that the maternal perspective — not only the professional perspective — needs to be taken into account if mothers are to succeed in the challenging process of reintroducing foods.

Food hypersensitivity is common in Swedish schoolchildren, especially oral reactions to fruit and gastrointestinal reactions to milk

This study examined the prevalence, symptom expression and risk factors for food hypersensitivity among Swedish schoolchildren.

Assessment of Allergy to Milk, Egg, Cod, and Wheat in Swedish Schoolchildren: A Population Based Cohort Study.

Objectives Knowledge about the prevalence of allergies to foods in childhood and adolescence is incomplete. The purpose of this study was to investigate the prevalence of allergies to milk, egg, cod, and wheat using reported data, clinical examinations, and double-blind placebo-controlled food challenges, and to describe the phenotypes of reported food hypersensitivity in a cohort of Swedish schoolchildren. Methods In a population-based cohort of 12-year-old children, the parents of 2612 (96% of invited) completed a questionnaire. Specific IgE antibodies to foods were analyzed in a random sample (n=695). Children reporting complete avoidance of milk, egg, cod, or wheat due to perceived hypersensitivity and without physician-diagnosed celiac disease were invited to undergo clinical examination that included specific IgE testing, a celiac screening test, and categorization into phenotypes of food hypersensitivity according to preset criteria. Children with possible food allergy were further evaluated with double-blind challenges. Results In this cohort, the prevalence of reported food allergy to milk, egg, cod, or wheat was 4.8%. Food allergy was diagnosed in 1.4% of the children after clinical evaluation and in 0.6% following double-blind placebo-controlled food challenge. After clinical examination, children who completely avoided one or more essential foods due to perceived food hypersensitivity were categorized with the following phenotypes: allergy (29%), outgrown allergy (19%), lactose intolerance (40%), and unclear (12%). Conclusions There was a high discrepancy in the prevalence of allergy to milk, egg, cod and wheat as assessed by reported data, clinical evaluation, and double-blind food challenges. Food hypersensitivity phenotyping according to preset criteria was helpful for identifying children with food allergy.

Milk allergy is a minor cause of milk avoidance due to perceived hypersensitivity among schoolchildren in Northern Sweden.

We investigated phenotypes of milk hypersensitivity among schoolchildren aged 11–12 in Northern Sweden.

New validated recipes for double-blind placebo-controlled low-dose food challenges

Double‐blind placebo‐controlled food challenges are considered the most reliable method to diagnose or rule out food allergy. Despite this, there are few validated challenge recipes available. The present study aimed to validate new recipes for low‐dose double‐blind placebo‐controlled food challenges in school children, by investigating whether there were any sensory differences between the active materials containing cows milk, hens egg, soy, wheat or cod, and the placebo materials. The challenge materials contained the same hypoallergenic amino acid–based product, with or without added food allergens. The test panels consisted of 275 school children, aged 8–10 and 14–15 yr, respectively, from five Swedish schools. Each participant tested at least one recipe. Standardized blinded triangle tests were performed to investigate whether any sensory differences could be detected between the active and placebo materials. In our final recipes, no significant differences could be detected between the active and placebo materials for any challenge food (p > 0.05). These results remained after stratification for age and gender. The taste of challenge materials was acceptable, and no unfavourable side effects related to test materials were observed. In summary, these new validated recipes for low‐dose double‐blinded food challenges contain common allergenic foods in childhood; cows milk, hens egg, soy, wheat and cod. All test materials contain the same liquid vehicle, which facilitates preparation and dosing. Our validated recipes increase the range of available recipes, and as they are easily prepared and dosed, they may facilitate the use of double‐blind placebo‐controlled food challenges in daily clinical practice.

To face fear : a qualitative study of adolescents' experiences of double-blind, placebo-controlled food challenges

Kokkinou, D; Georgountzou, A; Maggina, P; Taka, S; Roumbedaki, E; Douladiris, N; Papaevangelou, V; Xepapadaki, P; Papadopoulos, NG Allergy Dpt, 2nd Pediatric Clinic, University of Athens, Athens, Greece; 3rd department of Pediatrics, ‘ATTIKON’ General University Hospital, Athens, Greece; Center for Pediatrics and Child Health Institute of Human Development, University of Manchester, Manchester, United Kingdom

Food hypersensitivity phenotypes among Swedish schoolchildren reporting partial avoidance of milk

Food hypersensitivity phenotypes among Swedish schoolchildren reporting partial avoidance of milkBackground: The insecticidal activity of plant lectins against a large array of insect species has been well documented. Insecticidal activities were found to be associated mostly with the two main groups of plant lectins: monocot mannose-binding and chitin binding lectin groups. Known as natural defense agents, plant lectins have been implicated as antibiosis factors against insects and considered as promising candidates for biological pesticides. Mistletoe (Viscum album) fruit lectin MChbL belongs to chitin-binding lectin group and is considered to expose toxic lesions on human. In vitro, plant lectins effect lymphocyte mitogenesis, aggregate immunoglobulins, induce histamine release from basophiles and mast cells. We have studied MChbL cytotoxicity towards human peripheral blood lymphocytes (PBL) in humans. Method: Human PBL culture was used to study MChbL cytotoxicity by mitogen stimulated MTT assay. PB from 15 volunteers were examined during this study and control group was compound from 12 healthy donors. The optical densities was measured on spectrophotometer Multiscan MCC at 570 nm wavelength. Results: Our study showed that any dose of mitogen ConA have stimulated the human PBL (1 lg/mL OD 0.198, 10 lg/mL OD 0.467, 100 lg/mL OD 0.344), whereas MChbL has inhibited the proliferation of PBL MChbL in both concentration (10 lg/ mL, 500 lg/mL) decreasing the amount of the cells and their viability. Particularly, this was obvious at higher concentration of MChbL 500 lg/mL applied (OD 0.60). Conclusion: MChbL expose cytotoxical effects to human peripheral blood lymphocytes (PBL), when administrated at high concentration 500 lg/mL. However, low concentrations of MChbL were less cytotoxic to PBL and exhibit similar results as ConA at the concentration of 1 lg/mL. Most likely, approaches to use MChbL as natural bio-pesticide must be considered at dose-dependent manner and administrated in the nontoxic range.

Assessment of allergy to cow's milk, hen's egg, cod, and wheat in a population-based cohort of Swedish schoolchildren

Background: Although pretreatment is not routinely used before immunotherapy, it has been shown to reduce the reactions in patients using rush, cluster and conventional schedules. Our aim is to determine the possible preventive effects of various premedication usage on systemic and local reactions during cluster immunotherapy. Method: One hundred and eighteen patients receiving a total of 137 cluster immunotherapy protocols to mites, pollens, bee and wasp venoms were recruited in the study. Patients were randomized into 5 different groups according to premedication status as shown here below: Group 1: daily levosetirizine, Group 2: levosetirizine only 2 h prior to injections, Group 3: daily montelukast, Group 4: combinations of montelukast and levosetirizine and, Group 5: no premedication Patients were followed during build up and maintenance phase of immunotherapy, systemic and local reactions were reported. Reactions are reported according to World Allergy Organization Subcutaneous Systemic Reaction Grading System. Results: Most of the patients were female (%64.2), the most frequent allergen was house dust mites (50.4%). Of 69.3% of patients took premedication and 19.7% of patients had reactions during the build up phase. Reactions were more frequent in patients who have pollen allergy and have received pollen immunotherapy [P = 0.034; OR = 2.65 CI:95%, 1.05–6.63)]. The total frequency of the hypersensitivity reaction was significantly higher in patients not receiving premedication [14 (14.7%) vs 13 (31.0%), P = 0.028 ]. However no difference was detected between groups taking various drugs for premedication. The patients in the premedication group significantly experienced less local reactions (P = 0.033) although no difference in the frequency of systemic reactions was seen between the groups. Conclusion: These preliminary results suggest that the reaction risk is increased in pollen immunotherapy and premedication does not seem to prevent the frequency or severity of systemic reactions although it decreases the frequency of local reactions. As the number of patients recruited in the study increases, the effect of premedication on reactions may be clearer.A three year follow-up of asthma, respiratory symptoms and self-reported allergy, among pilots and cabin attendants