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Notes: It is currently recommended to administer a maintenance dose of 100 μg of venom at 4–6 week intervals for Hymenoptera venom immunotherapy (VIT), Because the optimal duration of therapy is not known, we decided to progressively prolong the interval between maintenance injections instead of accepting the risk of anaphylactic reactions when VIT is discontinued after a predetermined period. We report here on the results of a first phase of this interval extension programme, covering the gradual increase of the interval from 1-12 weeks over 19 months in 178 patients. A 12-week interval maintenance VIT could be achieved in 117/128 (91%) of yellow jacket venom (YJV) and in 35/50(70%) of honeybee venom (HBV) allergic patients. At the lime of the interview these 152 patients had been treated with 12-weekly 100 μg venom injections for an average period of 2 years without any untoward reaction to VIT. During this period of 48 YJV allergy sufferers experienced 77 field re-stings without systemic reaction (SR), and 17 HBV allergic subjects were restung at least 213 times in total, with one patient developing a very large local reaction and one a mild systemic reaction. In 26 of the 17S patients the interval of 12 weeks was not reached for various reasons, with a higher failure rate among the HBV allergic patients. Most Hymenoptera venom allergic patients can thus be safely and effectively treated with 12-weekly injections of 100 μg venom.

Notes: Background Hymenoptera stings can induce specific IgE (sIgE) to carbohydrate determinants (CD) on venom glycoproteins that cross-react with CD in pollen. sIgE to such cross-reacting CD (CCD) are believed to have little or no biological activity and thus may cause misdiagnosis of pollen sensitization after a sting.Objective To determine the prevalence of multiple false positive CAP results to pollen because of sting induced anti-CCD sIgE in Hymenoptera venom (HV) allergic patients and to investigate the association of such anti-CCD sIgE with features of ‘atopy’.Methods Skin prick tests (SPT) and CAP tests with grass, tree and weed pollen and with house dust mite (HDM) were carried out prospectively in 259 HV allergic patients and CAP tests with honeybee (HBV) and yellow jacket (YJV) venom were performed. Patients with negative pollen SPT associated with positive CAP tests to all three pollen groups were operationally defined as ‘CCD positive’. We investigated in selected ‘CCD positive’ patients the presence of anti-CCD sIgE by CAP tests with bromelain and studied the identity of CD in HVs and pollen by mutual sIgE inhibition tests with CD from proteinase treated HBV (HBV-CD) and Lolium perenne (Lol-CD) extracts.Results sIgE to all three pollen groups without positive SPT or history was found in 16% of 259 patients. The presence of anti-CCD sIgE was substantiated by positive CAP tests with bromelain in 14/14 and by inhibition of all pollen CAP tests with HBV-CD in 8/9 and with Lol-CD in 2/2 patients. Double venom (DV) positive CAP tests were present in 93% of ‘CCD positive’ patients and were in some associated with DV skin test positivity and allergy. The prevalence of ‘CCD positivity’ was significantly higher among HBV (23%) than among YJV (11%) allergic patients, but was also unexpectedly high among those with DV allergy (47%). ‘CCD positive’ patients were younger, had a higher total IgE and more sIgE to HDM than ‘CCD negative’ patients.Conclusion We have shown that the risk in HV allergic patients for misdiagnosis of multivalent pollen sensitization is 16%, and we have confirmed that sting induced anti-pollen sIgE are directed to similar CD in venoms and pollen. We found evidence that the recognition of CCD might be related to the ‘atopic’ trait. Importantly, a positive bromelain CAP test does not exclude clinical reactivity to both venoms in ‘CCD positive’ HV allergic patients.

Notes: We report a first case of occupational allergy to chicory (Cichorium intybus) in a vegetable wholesaler. Symptoms occurred after oral, cutaneous or inhalatory exposure. The patient also reported reactions after ingestion of botanically related endive (Cichorium endivia) and lettuce (Lactuca sativa.) We identified the responsible allergen by SDS-PAGE and immunoblot to be a 48-kDa protein, confined to the non-illuminated parts of the plants. No cross-reactivity was found with mugwort (Artemisia vulgaris) ryegrass (Lolium perenne) and birch (Betula verrucosa) pollen, which suggests that the vegetable is the primary allergenic material.

Notes: The clinical profile of anaphylactic reactions to bumble bees is described and successful immunotherapy with honey bee venom in seven bumble bee allergic patients is reported. The cause of the high frequency of sensitization to pollen in these patients is discussed.