Background: Recent studies indicated that fish-allergic patients may safely consume certain fish species. Multiplex IgE testing facilitates the identification of species tolerated by individual patients. Methods: Sera were collected from 263 fish-allergic patients from Austria, China, Denmark, Luxembourg, Norway and Spain. Specific (s) IgE to parvalbumins (PVs) from 10 fish species along with IgE to 7 raw and 6 heated fish extracts was quantified using a research version of the ALEX 2 assay. IgE-signatures of individual patients and patient groups were analyzed using SPSS and R. Results: sIgE to alpha-PV from ray, a cartilaginous fish, was not detected in 78% of the patients while up to 41% of the patients, depending on their country of origin, tested negative for at least one beta-PV. sIgE values were highest for mackerel and tuna PVs (>10 kUA/L) and significantly lower for cod (4.9 kUA/L) and sole PVs (2.55 kUA/L). 17% of the patients, although negative for PVs, tested positive for the respective fish extracts. Based on the absence of IgE to PVs and extracts, up to 21% of the patients were identified as potentially tolerating one or more bony fish. Up to 90% of the patients tested negative for ray. The probability of negativity to one fish based on negativity to others was calculated. Negativity to tuna and mackerel emerged as a good marker of negativity to additional bony fish. Conclusion: Measuring sIgE to PVs and extracts from evolutionary distant fish species indicates bony and cartilaginous fish species for tolerance-confirming food challenges.

Insect venom allergy is the most frequent cause of anaphylaxis in Europe and possibly worldwide. The majority of systemic allergic reactions after insect stings are caused by Hymenoptera and among these, vespid genera induce most of the systemic sting reactions (SSR). Honey bees are the second leading cause of SSR. Depending on the global region, other Hymenoptera such as different ant genera are responsible for SSR. Widely distributed hornets and bumblebees or local vespid or bee genera rarely induce SSR. Hematophagous insects such as mosquitoes and horse flies usually cause (large) local reactions while SSR occasionally occur. This position paper aims to identify either rare or locally important insects causing SSR as well as rarely occurring SSR after stings or bites of widely distributed insects. We summarized relevant venom or saliva allergens and intended to identify possible cross-reactivities between the insect allergens. Moreover, we aimed to locate diagnostic tests for research and routine diagnosis, which are sometimes only regionally available. Finally, we gathered information on disposable immunotherapies. Major allergens of most insects were identified, and cross-reactivity between insects was frequently observed. While some diagnostics and immunotherapies are locally available, standardized skin tests and immunotherapies are generally lacking in rare insect allergy.

BACKGROUND: Many patients report questionable drug hypersensitivity reactions (DHR) to betalactams. Allergological evaluation is required for objectivation. Recently, some researchers advocated direct drug provocation tests (DPTs) omitting a prior allergy-workup. However, DPTs bare the risk of severe side effects and are a scarce resource in overloaded healthcare-systems. We investigated the value of an approach using only the broadly available methods drug-specific history, specific IgE, and skin tests without DPT. METHODS: We conducted a chart review in a retrospective cohort of 932 patients in an allergy outpatient centre from 2016-2017. Patients had been submitted to drug-specific history and specific IgE-, skin prick-, intradermal- and patch-tests with early and late readings with a series of penicillins and cephalosporins but DPTs were no option. RESULTS: Overall, positive in vitro and/or skin tests were found in 96/932 (10.3%) patients. Drug-specific IgE was detected in 40/932 (4.3%) patients, 61/787 (7.8%) patients had positive skin tests. In vitro tests to Pencillin V showed the highest rate of positivity 24/479 (5.0%) and early readings of ampicillin the highest amongst the skin tests 3/49 (6.1%). Immediate skin tests were more often positive than delayed ones (75:45). The combination of all parameters including drug-specific history solved 346/932 (37.1%) cases while 586/932 (62.9%) remained unresolved. Females and younger children carried a lower risk for positive tests (p<0.05, Χ2-test). CONCLUSIONS: Testing with betalactams applying simple, cheap, and safe skin and blood tests can solve a third of DHR-cases on a high throughput scale.