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Notes: Abstract For quantitative use of skin prick tests (SPTs), the circumference of the wheal and/or the flare is outlined by a pen, and transferred to a paper by adhesive tape. The biological response is considered proportional to this area. We have previously developed software, the SPT-scanner, for determination of SPT areas (5–500 mm2) by a hand-held scanner and a personal computer. This study is aimed at comparing the SPT-scanner with another semiautomated system, where the outline of the wheal is followed by a digitizer pen. Comparing 2080 SPT areas from a pharmacological study of cetirizine, the two systems correlated well (r=0.980,p〈0.001), the digitizer generally giving larger areas than the SPT-scanner. Probably, the line is considered as a part of the wheal/flare in the digitizing system, whereas the scanner only detects areas within the circumference. In conclusion, the SPT scanner is objective and reproducible for rapid SPT area determination.

Notes: Abstract For production of an antibody against histamine, this was coupled to human serum albumin (HSA) and used for immunization of rabbits. To test the antiserum, an immunoradiometric assay was developed comprising solid-phase bound histamine, antisera and radiolabelled protein A. Titration and inhibition experiments revealed that histamine adsorbed onto a solid-phase could bind the antiserum. However, neither free histamine nor histamine coupled to unrelated carriers could inhibit the binding of antiserum to the solid-phase histamine. Cross-reactivity was demonstrated between HSA and solid-phase bound histamine, as the immunoradiometric assay was inhibited by HSA. This unexpected cross-reactivity was established, as a commercially available antiserum with specificity to HSA without histamine also bound to the solid-phase bound histamine. It is suggested that preparations of antibodies against histamine are tested for this possible cross-reactivity.

Notes: The present study aimed at evaluating the effects of daily repeated exposures to low cobalt or chromate concentrations on the hands of patients with hand eczema and cobalt or chromate allergy. For 2 weeks, the patients immersed a finger for 10 min daily into the appropriate metal salt solution in water. During the 1st week, this was a 10 or 50 mg/l cobalt concentration or a 10 mg/l chromate concentration, and, during the 2nd week, a 100 or 200 mg/l cobalt concentration or a 100 mg/l chromate concentration. This regimen elicited a flare of hand eczema only in the chromate-exposed chromate-sensitive patients. During the exposure period, accumulation of cobalt or chromate in the nail was demonstrated. Standardization of chemical methods of quantification of skin exposure to allergens, combined with experimental exposure studies in patients with specific contact allergy, will increase the possibility of providing evidence-based medicine in the area of allergic contact dermatitis in the future.

Notes: Background Recent reports have indicated cetirizine, a potent H1-receptor antagonist, to possess a number of anti-inflammatory effects, e.g. inhibition of mast cell degranulation and inhibition of leucocyte migration and activation.Objective The aim of this study was to compare the effects of cetirizine on skin responses and mediator release in intact skin in immediate and developing late-phase allergic reactions by microdialysis technique.Methods Cetirizine 10 mg once daily or matching placebo were administered to 10 atopic subjects for 6 days followed by a 2-week washout in a randomized, double-blind, placebo-controlled, cross-over trial. Immediate skin test responses to allergen, codeine, and histamine and late-phase reactions to allergen were assessed. The time course of extracellular levels of inflammatory mediators in intact skin were monitored by microdialysis techniques using 2 kDa and 3 MDa cut-off fibers, respectively.Results Cetirizine significantly reduced immediate weal and flare reactions to allergen, codeine, and histamine. Injection of allergen, but not buffer controls, induced a significant release of histamine, tryptase, prostaglandin D2, total protein, and eosinophilic cationic protein. No significant increase of leukotriene B4 and myeloperoxidase was observed. Cetirizine inhibited early total protein extravasation by 40%, but this did not reach a significant level. None of the inflammatory mediators were significantly inhibited by cetirizine. Cetirizine significantly reduced the late-phase skin induration to allergen by approximately 30%.Conclusion Cetirizine potently reduced skin responses in immediate allergic reactions without inhibition of early mediators. These data indicate cetirizine to be a potent H1-receptor antagonist with no effect on mast cell activation. It did not inhibit any of the late-phase mediators, but it reduced the late skin reaction. These data suggest that mediators other than those actually measured may play a significant role in the clinical late-phase reaction.

Notes: Allergen-specific immunotherapy is a well-documented treatment for allergic rhinitis, asthma, and allergy to Hymenoptera venoms. The drawbacks of injection immunotherapy are related to the risk of inducing systemic side-effects (especially during the induction phase), the time used to reach the maintenance dose, and the percentage of patients completing the induction phase).〈section xml:id="abs1-2"〉〈title type="main"〉ObjectiveTo investigate the practicability and safety of three different patient-friendly induction regimens of clustered immunotherapy (several injections administered during each visit).〈section xml:id="abs1-3"〉〈title type="main"〉MethodsSince 1990, three different clustered induction regimens (regimen 1 = exclusively aqueous extracts; regimen 2 = a combination of aqueous and alum depot extracts; and regimen 3 = induction using exclusively alum depot extracts) have been investigated in 657 patients (10 369 injections).〈section xml:id="abs1-4"〉〈title type="main"〉ResultsA total of 454 systemic (immediate and late) reactions were observed in 257 patients corresponding to 4.4% of the injections and 39.1% of the patients. Most of the systemic reactions were of little or no clinical importance (93% grade 1 and grade 2) and 〈 1% anaphylactic reactions. The 8-week induction regimen using exclusively alum depot extracts showed a statistical significant lower frequency and severity of systemic side-effects. Immunotherapy with cat and mite allergen extracts showed the highest frequency of severe side-effects, which may be related to these extracts being used predominantly in asthmatic patients. The lowest frequency of systemic side-effects was observed in patients allergic to Hymenoptera venoms and these patients furthermore showed the highest number of patients (97%) completing the induction phase.〈section xml:id="abs1-5"〉〈title type="main"〉ConclusionAn 8-week clustered induction regimen using alum depot extract seems an acceptable compromise in relation to a reduction in the time used to reach maintenance dose and the risk of inducing clinically relevant systemic side-effects, and consequently imply a reduction in the costs of the treatment.

Notes: Background Allergen-specific immunotherapy (SIT) is associated with increased levels of allergen-specific IgG in serum. However, it is not clear to what extent qualitative changes in the allergen binding capacity of IgG may be induced as well.Objective The purpose of this study was to investigate the influences of SIT on antibody affinity.Methods The binding affinity of purified serum IgG1, IgG4 and IgE to the major allergen in birch (Betula verrucosa) pollen, Bet v 1, was analysed by surface plasmon resonance. The antibodies were obtained from 10 birch pollen-allergic patients receiving SIT and from 10 patients with no SIT.Results The patients having received SIT have a significant higher titre of anti-Bet v 1 antibodies in their blood, but the affinity to Bet v 1 of allergen-specific IgE, IgG1 and IgG4 does not differ between the two groups. For IgG1 and IgG4, correlations between less allergic symptoms and affinity of the antibodies were observed both in the SIT group and to a smaller extent in the non-SIT group.Conclusion SIT has no effect on antibody affinity of allergen-specific IgE, IgG1 or IgG4. Allergic patients with high-affinity IgG1 and IgG4 antibodies report less symptoms than patients with low-affinity antibodies.

Notes: Background The history of the severity of seasonal allergic symptoms is often obtained post-seasonally as a retrospective assessment. Correct rating is essential when determining the efficacy of pharmaceutical treatment, indications for allergen-specific immunotherapy (SIT), or inclusion into controlled clinical studies.Objectives To investigate the agreement between in- and post-seasonal ratings of seasonal symptoms, and to investigate whether the effect of SIT could be detected retrospectively.Material and methods Thirty-five birch pollen-allergic patients were allocated to SIT or placebo in a double-blind study. Assessment of severity of symptoms from the nose, eyes and lungs were performed daily during the season 2000, and post-seasonally 6 months after the season in 1999 and 2000. A four-point verbal descriptor scale (VDS-4) was used at all occasions. A mean in-seasonal symptom rating was calculated for four periods: the day, the week and the 2 weeks with the highest symptoms score, and the arithmetic season (the period covering the mid-90% of the accumulated pollen count). In- and post-seasonal ratings were compared with Cohen's weighted kappa (κw).Results Agreement between in-seasonal and retrospective ratings was fair to moderate (κw: 0.30–0.60). Post-seasonal ratings were most related to symptoms experienced in the week with the highest symptom scores, and least related to the arithmetic season. The post-seasonal ratings were significantly skewed towards higher symptom scores than the mean of in-seasonal ratings in periods ≥ 2 weeks. Despite being comparable before intervention, only in the SIT-treated group was a significant decrease in post-season ratings of severity of rhinoconjunctivitis apparent (P 〈 0.05). Asthma scores were not reduced but fewer patients in the SIT group reported lung symptoms (P 〈 0.001).Conclusion Post-seasonal assessment of seasonal allergic symptoms generally describes a shorter period than the arithmetic season. Post-season assessment tends to over-rate average symptom severity, but appears sufficiently sensitive to detect treatment efficacy.

Notes: Background Asthma has been reported to be rare among Inuits, but so far total and specific IgE levels have never been determined in arctic populations.Objective To determine the prevalence of atopy in children living in an arctic environment, and to examine whether atopy and total IgE levels were associated with parental place of birth, as a measure of ethnicity, and travel history.Material and Methods All schoolchildren in Sisimiut, a community on the West coast of Greenland, were screened for atopy. Blood samples were analysed for total IgE and for specific IgE against inhalant and food allergens. Information on place of birth of children and their parents was obtained from national registries. Information on travel history was obtained from self-administered questionnaires.Results A total of 1031 schoolchildren aged 5 to 18 years had a blood sample drawn (85% of available children for the study). Of these, 151 (14.6%) children were sensitized to at least one inhalant allergen and 42 (4.1%) to at least one food allergen. Sensitization to grass was most common, whereas sensitization to mugwort, birch, animal-dander and house-dust mite was infrequent. Children whose parents were both born abroad had a higher risk of sensitization to inhalant allergens compared with children born of Greenlandic parents (OR = 8.6, 95% CI 2.8–27.1). Furthermore, children who had been abroad had a higher risk of sensitization towards pollen (OR = 1.6, 95% CI 1.0–2.5) and animal-dander (OR = 2.1, 95% CI 1.0–4.6) after adjustment for confounders. Both atopic and non-atopic children demonstrated high levels of total IgE (medians of 251 and 58 kU/L).Conclusions Compared with European findings Greenlandic children have high levels of total IgE but a low prevalence of allergic sensitization towards inhalant allergens. This may be due to a low genetic susceptibility to atopy and less allergen exposure, as well as to living conditions in an arctic environment.