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.

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.