allergy
A voluntary registry for peanut and tree nut allergy: characteristics of the first 5149 registrants.

Sicherer SH, Furlong TJ, Munoz-Furlong A, Burks AW, Sampson HA.

Elliot and Roslyn Jaffe Food Allergy Institute, Division of Allergy and Immunology, Department of Pediatrics, Mount Sinai School of Medicine, New York, NY 10029-6574, USA.

BACKGROUND: A voluntary registry of individuals with peanut and/or tree nut allergy was established in 1997 to learn more about these food allergies. OBJECTIVE: The purpose of this study was to elucidate a variety of features of peanut and tree nut allergy among the first 5149 registry participants. METHODS: The registry was established through use of a structured questionnaire distributed to all members of the Food Allergy and Anaphylaxis Network and to patients by allergists. Parental surrogates completed the forms for children under the age of 18 years. RESULTS: Registrants were primarily children (89% of registrants were younger than 18 years of age; the median age was 5 years), reflecting the membership of the Network. Isolated peanut allergy was reported by 3482 registrants (68%), isolated tree nut allergy by 464 (9%), and allergy to both foods by 1203 (23%). Registrants were more likely to have been born in October, November, or December (odds ratio, 1.2; 95% CI, 1.18-1.23; P <.0001). The median age of reaction to peanut was 14 months, and the median age of reaction to tree nuts was 36 months; these represented the first known exposure for 74% and 68% of registrants, respectively. One half of the reactions involved more than 1 organ system, and more than 75% required treatment, frequently from medical personnel. Registrants with asthma were more likely than those without asthma to have severe reactions (33% vs 21%; P <.0001). In comparison with initial reactions, subsequent reactions due to accidental ingestion were more severe, more common outside the home, and more likely to be treated with epinephrine. CONCLUSIONS: Allergic reactions to peanut and tree nut are frequently severe, often occur on the first known exposure, and can become more severe over time.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11447394&dopt=Abstract allergy medicine



allergy
Reducing the need for food allergen challenges in young children: a comparison of in vitro with in vivo tests.

Hill DJ, Hosking CS, Reyes-Benito LV.

Department of Allergy, Royal Children's Hospital, Flemington Road, Melbourne, Victoria 3052, Australia. allergy cryptic.rch.unimelb.edu.au

BACKGROUND: Double-blind placebo-controlled food challenges (DBPCFC), the gold standard for the diagnosis of food hypersensitivity, are time-consuming and not without risk. We have recently reported skin prick test (SPT) weal diameters to cow's milk, egg and peanut above which infants and young children referred for investigation of suspected food allergy showed an adverse reaction on food challenge. We have termed these the "100% diagnostic SPT levels". In this study, we compare in vivo with in vitro measurement of IgE antibody levels to three common food allergens--cow's milk, egg and peanut--in infants and young children with suspected food allergy, in order to reduce the need for food challenges. METHODS: SPT and Enzyme Allergo-sorbent Test (EAST) (from 1992 to 1998) and CAP values (from 1999 to 2000) were performed in 820 children < 2 years of age with suspected allergy to cow's milk and/or egg and/or peanut. SPT levels previously shown to be diagnostic of challenge-proven allergy to cow's milk, egg and peanut were used as the "100% diagnostic SPT levels" and compared with EAST and CAP values associated with IgE food allergy according to the manufacturer's definition. RESULTS: McNemar's test showed a significant difference between the "100% diagnostic SPT levels" and positive EAST in identifying patients who did not require food challenge for cow's milk (P = 0.01), egg (P < 10-6) and peanut (P < 10-6), and a significant difference between the "100% diagnostic SPT levels" and positive CAP (P < 10-6) for egg and peanut but not cow's milk. Twenty-three per cent of food challenges which, based on the results of EAST and CAP, would have been necessary to confirm the diagnosis of food allergy were avoided by the use of the "100% diagnostic SPT levels" . CONCLUSION: The use of the "100% diagnostic SPT levels" compared with in vitro measurement of IgE antibody to cow's milk, egg and peanut reduces the need for food challenge in young children with suspected food allergy.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11467993&dopt=Abstract allergy medicine



allergy
Coughing in pre-school children in general practice: when are RAST's for inhalation allergy indicated?

Eysink PE, Bottema BJ, ter Riet G, Aalberse RC, Stapel SO, Bindels PJ.

Department of General Practice, Division Clinical Methods and Public Health, Academic Medical Center - University of Amsterdam, Amsterdam, The Netherlands.

To identify patterns of clinical history associated with extreme (high or low) probabilities of allergic sensitization in coughing children so as to restrict allergy testing to those with an intermediate probability of sensitization. A total of 752 children, aged 1-4, visiting their GPs for coughing (>or=5 days), were tested for IgE-antibodies to house dust mite, cat and dog [RadioAllergoSorbent Test (RAST)]. Parents completed a questionnaire on family history of atopy, breastfeeding, smoking, pets, and floor covering. Data of 640 children could be analyzed, 83 (13%) were IgE-positive. In a logistic regression analysis, a scoring formula for the prediction of being IgE-positive was constructed using variables from the patient's history. Significant contributors for sensitization were: age (3-4 yr), infantile eczema, positive family history of mite-allergy, sibling(s) with pollen-allergy, and smoking by parents. If only one of these characteristics is present, the probability of sensitization is < 25%. In such cases watchful waiting may be preferred over allergy testing. In other cases, a negative RAST may help to exclude sensitization, whereas a positive RAST helps to establish the diagnosis. Thus, acting on clinical history alone may save approximately 80% of RAST's. Patient history-derived information contributes to distinguishing children who are at low risk for sensitization to house dust mite, cat, and dog. The scoring formula may help GPs to identify children with a low probability of being sensitized. This may form the basis for watchful waiting. In others, allergy testing may be useful to gain more diagnostic certainty.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=15482513&dopt=Abstract allergy medicine



allergy
Food allergy and atopic dermatitis in infancy: an epidemiologic study.

Hill DJ, Hosking CS.

Department of Allergy, Royal Children's Hospital, Flemington Road, Parkville, Victoria 3052, Australia. allergy.clinic rch.org.au

Atopic dermatitis is common in infancy. The role of food allergy in atopic dermatitis of infancy is unclear. We examined the relationship between atopic dermatitis and immunoglobulin E (IgE)-mediated food allergy in infancy. A birth cohort of 620 infants with a family history of eczema, asthma, hayfever or immediate food allergy in a parent or sibling: 487 children had complete data including skin prick tests (SPTs) to evaluate IgE-mediated food allergy to cow milk, egg and peanut. Participants were grouped as no atopic dermatitis (Gp 0) or in quartiles of increasing severity of atopic dermatitis (Gps 1-4) quantified by days of topical steroid use as reported monthly. Adverse reactions to foods were recorded. The cumulative prevalence of atopic dermatitis was 28.9% to 12 months (10.3% of the cohort of moderate severity). As atopic dermatitis severity increased so did the prevalence of IgE-mediated food allergy (Gp 0, 40/346 vs. Gp 1, 6/36 vs. Gp 2, 8/35 vs. Gp 3, 12/35 vs. Gp 4, 24/35; chi(2) = 76; p < 10(-6)), and the frequency of reported adverse food allergy reactions (Gp 0, 43/346 vs. Gp 1, 4/36 vs. Gp 2, 8/35, vs. Gp 3, 5/35, vs. Gp 4, 13/35; chi(2) = 17; p = 0.002). The relative risk of an infant with atopic dermatitis having IgE-mediated food allergy is 5.9 for the most severely affected group. Atopic dermatitis is common in infancy. There is a strong association between IgE-mediated food allergy and atopic dermatitis in this age group.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=15482517&dopt=Abstract allergy medicine



allergy
The diagnostic value of skin prick testing in children with food allergy.

Hill DJ, Heine RG, Hosking CS.

Department of Allergy, Royal Children's Hospital, Flemington Road, Parkville, Victoria 3052, Australia. allergy.clinic rch.org.au

The diagnostic accuracy of the skin prick test (SPT) in food allergy is controversial. We have developed diagnostic cut-off levels for SPT in children with allergy to cow milk, egg and peanut. Based on 555 open food challenges in 467 children (median age 3.0 yr) we defined food-specific SPT weal diameters that were '100% diagnostic' for allergy to cow milk (>or=8 mm), egg (>or=7 mm) and peanut (>or=8 mm). In children < 2 yr of age, the corresponding weal diameters were >or=6 mm, >or=5 mm and >or=4 mm, respectively. These SPT cut-off levels were prospectively validated in 90 consecutive children <or=2 yr with challenge-proven food allergy. In young infants under 6 months of age who have not previously been exposed to a particular food item, the SPT were often negative or below the diagnostic cut-off but reached the diagnostic cut-off at the time of challenge in the second year of life. We assessed the diagnostic agreement between food-specific immunoglobulin E (IgE) antibody levels and SPT in a cohort of 820 infants and children under 2 yr of age (median age 13.1 months) with suspected allergy to cow milk, egg or peanut. When applying published 95%-positive predictive CAP values, the diagnostic accuracy of SPT and IgE antibody levels was similar for cow milk, but SPT was more sensitive in diagnosing allergy to egg (p < 0.0001) and peanut (p < 0.0001). Further studies are required to define age-specific diagnostic IgE antibody and SPT cut-off levels use in infants under 2 yr of age with suspected food allergies.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=15482519&dopt=Abstract allergy medicine



allergy
General paediatricians and the case of resolving peanut allergy.

Rangaraj S, Ramanathan V, Tuthill DP, Spear E, Hourihane JO, Alfaham M.

Department of Child Health, Llandough Hospital, Penarth, Cardiff, UK.

Children with peanut allergy are almost always advised to avoid nuts for life. There have been recent reports from academic centres that in some cases the allergy might resolve and thus these dietary restrictions can be lifted. To evaluate resolution of peanut allergy in a selected group of children in a general paediatric setting. Children 4-16 yr old with a clear history of an allergic reaction to peanuts who had not had any reaction in the previous 2 yr were eligible. Specific immunoglobulin E (IgE) or skin prick test (SPT) at the time of diagnosis was sought. A SPT and specific IgE was then done and if this was <or= 8 mm and <or= 17.5 kU[A]/l respectively, a double-blind placebo-controlled food challenge was undertaken. A negative challenge consisted of tolerance to a cumulative dose of 15.8 g peanuts followed by an open challenge. From the 82 case notes reviewed 54 children were eligible to participate. Twenty-nine agreed to participate and underwent SPT (29) and specific IgE (28). Of these children eight were eligible for food challenge. Four challenges were negative and four positive. Peanut allergy may resolve in approximately 15% of selected children attending an allergy clinic run by general paediatricians in a district general hospital. Food challenge constitutes the appropriate way of removing the burden that comes with a diagnosis of peanut allergy and enables dietary restriction to cease.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=15482521&dopt=Abstract allergy medicine



allergy
Epidemiological change of atopic dermatitis and food allergy in school-aged children in Korea between 1995 and 2000.

Oh JW, Pyun BY, Choung JT, Ahn KM, Kim CH, Song SW, Son JA, Lee SY, Lee SI.

Department of Pediatrics, Hanyang University, Korea.

Little is known about the prevalence of atopic dermatitis and food allergy outside North America and Europe. We evaluated the prevalence of atopic dermatitis and food allergy with the comparison of prevalence between 1995 and 2000 in Korea and evaluated the correlation of prevalence between atopic dermatitis and food allergy. A cross-sectional questionnaire survey was conducted on random samples of schoolchildren 6 to 14 yr at two time points, 1995 and 2000 throughout Korea. The last twelve months prevalence of atopic dermatitis in Korean school-aged children was increased from 1995 to 2000. The twelve-month prevalence of atopic dermatitis and food allergy were higher in Seoul than in any other provincial cities in 1995, but the prevalence of both diseases in Seoul and Provincial Centers became to be similar in 2000. The rate responded to food allergy of children with atopic dermatitis (9.5%) was lower than that of the western countries (60%). And our data demonstrated paternal and maternal allergy history is very significantly correlated to developing atopic dermatitis in their offspring. The further objective evaluations are required to confirm these outcomes because the environmental and risk factors may be different among the countries according to their living cultures.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=15483350&dopt=Abstract allergy medicine