One-year survey of paediatric anaphylaxis in an allergy department.

AIM: To determine the frequency of anaphylaxis in an allergy outpatient department, allowing a better understanding regarding aetiology, clinical manifestations and management, in children and adolescents. METHODS: From among 3646 patients up to 18 years old observed during one-year period, we included those with history of anaphylaxis reported by allergists. RESULTS: Sixty-four children had history of anaphylaxis (prevalence of 1.8%), with mean age 8.1±5.5 years, 61% being male. Median age of the first anaphylactic episode was 3 years (1 month-17 years). The majority of patients had food-induced anaphylaxis (84%): milk 22, egg 7, peanut 6, tree nuts 6, fresh fruits 6, crustaceans 4, fish 4 and wheat 2. Food-associated exercise-induced anaphylaxis was reported in 2 adolescents. Drug-induced anaphylaxis occurred in 8%: 4 non-steroidal anti-inflammatory drugs and 1 amoxicillin. Three children had cold-induced anaphylaxis, one adolescent had anaphylaxis to latex and one child had anaphylaxis to insect sting. The majority (73%) had no previous diagnosis of the etiologic factor. Symptoms reported were mainly mucocutaneous (94%) and respiratory (84%), followed by gastrointestinal (42%) and cardiovascular (25%). Fifty-one patients were admitted to the emergency department, although only 33% were treated with epinephrine. Recurrence of anaphylaxis occurred in 26 patients (3 or more episodes in 14). CONCLUSIONS: In our paediatric population, the main triggering agent of anaphylaxis was IgE-mediated food allergy. Epinephrine is underused, as reported by others. Often, children have several episodes before being assessed by an allergist. We stress the importance of systematic notification and improvement of educational programmes in order to achieve a better preventive and therapeutic management of this life-threatening entity.

Cow's milk dependent exercise-induced urticaria after oral tolerance induction in an adolescent

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Systemic corticosteroid hypersensitivity in children.

We describe 5 cases of immediate-type reactions to systemic corticosteroids observed during the last 2 decades in boys aged 2, 4, 8, 9, and 10 years. Symptoms ranged from generalized urticaria and angioedema to anaphylactic shock immediately after administration. Oral betamethasone was implicated in 2 cases, oral prednisolone in 2 cases, and intravenous prednisolone in 1 case. The parents of patient 5 refused the skin tests. The remaining patients underwent skin prick tests with the following undiluted corticosteroids: parenteral prednisolone, oral prednisolone, parenteral methylprednisolone, parenteral dexamethasone, parenteral hydrocortisone, and oral betamethasone. If the results were negative, intradermal tests were performed with the same drugs at increasing concentrations. Skin test results were positive for all suspect corticosteroids, thus indicating an immunoglobulin E-mediated mechanism. Two patients had positive skin test results to other corticosteroids, suggesting cross-reactivity. An oral challenge test was performed with deflazacort in 4 cases and with betamethasone in 1 case; the results were negative.

Barnacle allergy: allergen characterization and cross-reactivity with mites.

BACKGROUND: Barnacles are a type of seafood with worldwide distribution and abundant along the shores of temperate seas. They are particularly appreciated and regularly consumed in Portugal as well as in Spain, France and South America, but barnacle allergy is a rare condition of which there is only one reference in the indexed literature. The molecular allergens and possible cross-reactivity phenomena implicated (namely with mites) have not been established. OBJECTIVE: To demonstrate the IgE-mediated allergy to barnacle and to identify the proteins implicated as well as possible cross-reactivity phenomena with mites. METHODS: We report the clinical and laboratory data of five patients with documented IgE-mediated allergy to barnacle. The diagnosis was based on a suggestive clinical history combined with positive skin prick tests (SPT) to barnacle--prick to prick method. Two barnacle extracts were prepared (raw and cooked barnacle) and sodium dodecylsulphate polyacrylamide gel electrophoresis (SDS-PAGE) and IgE-immunoblotting were performed. An immunoblotting inhibition assay with Dermatophagoides pteronyssinus was also done in order to evaluate cross-reactivity. RESULTS: All patients had mite-related asthma and the allergic rhinoconjunctivitis; they all experienced mucocutaneous symptoms. All of them had positive SPT to barnacle, and the immunoblotting showed several allergenic fractions with a wide molecular weight range (19 - 94 kDa). The D. pteronyssinus extract inhibited several IgE-binding protein fractions in the barnacle extract. CONCLUSIONS: We describe five patients with IgE-mediated barnacle allergy. We also describe a group of IgE-binding+proteins between 30 and 75 kDa as the allergenic fractions of this type of Crustacea. Cross-reactivity with D. pteronyssinus was demonstrated in two cases.

Quantitative skin prick tests and specific IgE (CAP System) for D. pteronissynus--correlation of results in a paediatric population.

The CAP System compared with RAST has a greater sensitivity, with the same specificity, as well as an excellent correlation with skin prick tests (SPT), as documented by others. Standardization of SPT is essential for routine and investigational purposes. We used a standardized lancet (DHS), and the methodology of reading the SPT was a computerized digitalized graphics tablet coupled to an IBM-PC AT using CAD software, expressing the result as wheal areas with cut off +/- at 7 mm2. The method is precise and reproducible with a mean coefficient of variation (cv) intratester--T1: 3.1%, T2: 3.5% and a cv intertester: 2.93%. We compare the results of SPT of two different allergen extracts for Dermatophagoides Pteronissynus (DPt) (Bencard; Merck/Allergo-Pharma, standardized in SBU) and correlate them with specific IgE, in 122 patients, 72 males and 50 females, aged 3 to 19 years. The results between the extracts and the results of specific IgE obtained by CAP System with each of the extracts, were correlated. 34 patients were considered to be non atopic. 88 patients showed at least one positive result with one test, being those used to correlate the positive results.... The results showed good correlations for quantitative SPT between Bencard and Merck/Allergo-Pharma, as well as for the capacity of eliciting positive results. When SPT were compared to specific IgE as +/- and as quantitative results, there were good correlation for Bencard/CAP and Merck/CAP. The results obtained suggest that CAP can be used to validate allergen extracts of DPt and that studies with other extract are advisable.

ALATOP:sensitivity, specificity and predictive value of a new "in vitro" screening test of atopy.

UNLABELLED: The limitations of total IgE for the screening of atopy, gave rise to in vitro multispecific IgE tests to common allergens. These should have an increased sensitivity and specificity when compared to total IgE. Previous data showed the interest of such tests in screening procedures. ALATOP is a new in vitro multispecific IgE test including common aero and food allergens, in liquid phase, for paediatric and adult population. The result is expressed only in positive/negative. The aim of the study was to determine the sensitivity, specificity, positive and negative predictive value and test efficiency, by comparing the results obtained in 266 paediatric patients (selected in our Unit based on a good correlation between clinical history and skin prick tests--SPT), between ALATOP and SPT. RESULTS: 1) Sensitivity: 89.57%; 2) Specificity: 98.06%; 3) Positive predictive value: 98.65%; 4) Negative predictive value: 85.59%; 5) Efficiency of the test: 92.86%; 6) Reproducibility of the test--average: 5.63%. Based on this results and when they are compared to single specific IgE determinations, that are assumed to be about 80% of the sensitivity of SPT, ALATOP showed excellent results, allowing its use in the screening of atopic disease.