Secondary soy allergy in children with birch pollen allergy may cause both chronic and acute symptoms.

BACKGROUND: Secondary soy allergy occurring in tree pollen allergic patients may cause acute symptoms. METHODS: We selected children with birch pollen allergy suspected of also being soy allergic (SA). Soy allergy was proven based on one of the following: (i) a clear-cut clinical history; (ii) a positive provocation test; and (iii) elimination and reintroduction of soy. Skin prick tests (SPT) were performed with a commercial soy extract and with soy flour. Specific IgE to Gly m 4, Gly m 5, and Gly m 6 was determined by means of ImmunoCAP and ISAC. Eight soy-tolerant atopic children being CAP rGly m 4-negative served as a control group for skin testing. RESULTS: Of 15 subjects with birch pollen allergy and being suspected of soy allergy, eight of them proved to be SA; 7/15 subjects proved to be soy tolerant (ST). Besides acute symptoms in 8/8 SA subjects, 3/8 subjects also had been suffering from severe chronic complaints because of soy allergy. SPT with commercial soy extract was negative in all SA and ST subjects tested. SPT with soy flour was positive in 8/8 SA and in 5/6 ST subjects, but negative in all 8 controls (p < 0.0001); the median weal diameter was 7.7 mm in SA subjects, compared to 3 mm in ST subjects (p < 0.01). The median IgE level to rGly m 4 using CAP and ISAC was, respectively, 32.4 kU/l and 4.0 ISU in SA subjects, compared to 6.2 kU/l and 0.4 ISU in ST subjects (p < 0.05). Analysis of IgE to nGly m 5 and nGly m 6, using CAP or ISAC, showed no significant differences between SA and ST subjects. CONCLUSIONS: Secondary soy allergy may cause severe chronic besides acute symptoms. SPT with soy flour is a sensitive and specific tool in detecting soy sensitization. SPT with soy flour, CAP rGly m 4, and ISAC rGLY m 4 are valuable tools in the diagnosis of birch-pollen-associated secondary soy allergy.

Anaphylaxis in referred pediatric patients: demographic and clinical features, triggers, and therapeutic approach.

Anaphylaxis remains under-diagnosed and under-treated. A better knowledge of patterns and triggers of anaphylaxis might contribute to a better management. In this study we evaluated the demographic and clinical features of anaphylaxis in pediatric patients, as well as its triggers and therapeutic approach. From May 1st 2004 until April 30th 2006 we prospectively collected data on all patients referred for investigation of anaphylaxis to the pediatric department of the University Hospital Gasthuisberg Leuven and to two private pediatric practices. Data were stored in a MYSQL database by use of an online encrypted web form. Sixty-four cases of anaphylaxis occurred in 48 children, aged 6 months to 14.8 years. Twenty-seven episodes (42.2%) occurred at home. The symptoms were dermatologic in 62 (96.9%) episodes, respiratory in 57 (89.1%), gastrointestinal in 19 (29.7%), cardiovascular in 14 (21.8%), and neurological or behavioural in 19 (29.7%). Antihistamines were administered in 41/57 (71.9%) cases, corticosteroids in 26/57 (45.6%), beta-2-mimetics in 14/57 (24.6%), and adrenaline in 11/57 (19.3%). Out of nine cases where Epipen was available at the moment of anaphylaxis, it was administered in one case only. Food was the cause of anaphylaxis in 42/55 (76.4%) cases with identified trigger, while medication, insect stings, latex, and birch pollen triggered 5 (9.1%), 4 (7.3%), 3 (5.5%), and 1 (1.8%) case(s), respectively. Allergy to the trigger was known prior to anaphylaxis in 19/55 (34.5%) cases. In conclusion, anaphylaxis in pediatric patients generally presents with dermatologic and respiratory symptoms, while in 1/5 episodes cardiovascular symptoms occur. Food is by far the most frequent trigger. Allergy to the trigger is known in 1/3 cases only. Anaphylaxis is under-treated, even when appropriate medication is available.

Allergy to cooked white potatoes in infants and young children: A cause of severe, chronic allergic disease.

BACKGROUND: Cases of allergy to cooked potato in children have been reported, some with immediate and others with late reactions. The clinical effects of chronic allergic reactions to potato and the effectiveness of diet on such reactions have not been described previously. OBJECTIVE: We sought to evaluate the importance of cooked potato as an allergenic food in individual cases of atopy in children. METHODS: Eight atopic children were selected on the basis of suspicion of allergy to cooked potatoes: all had potato-specific IgE, 2 of 8 had experienced immediate allergic reactions, and 6 of 8 had eczema that improved with a potato-elimination diet (decrease in severity scoring of atopic dermatis [SCORAD] index of >50%). The patients were evaluated by using skin prick tests with homemade cooked and noncooked potato extracts and with a commercial extract and by using IgE immunoblots from SDS-PAGE patterns of potato extract. Seven patients were challenged with cooked potato. The control group consisted of 9 age-matched atopic children, 8 of them with eczema. RESULTS: The mean SCORAD index decreased from 43.3 before to 11.5 after elimination of potato from the diet. Potato CAP values ranged from 3.71 to greater than 100 kUa/L. Potato challenge results were positive in 7 of 7 patients. Skin prick test responses were positive for cooked potato extracts in 7 of 7 patients, for noncooked extracts in 7 of 7 patients, and for the commercial extract in 8 of 8 patients compared with in 0 of 9, 1 of 9, and 1 of 9 subjects in the control group, respectively. During immunoblotting, 8 of 8 patient sera recognized one or more protein bands compared with 0 of 9 control subject sera. CONCLUSION: Allergy to cooked potatoes is a cause of severe allergic disease, with immediate reactions and eczema in some atopic infants and young children.