Nonsteroidal anti-inflammatory drugs-induced urticaria/angioedema does not seem to precede the onset of CU over the medium term. Further research including a longer follow-up is necessary to verify this observation.

This paper highlights a clinical case of a patient suffering bronchial asthma and rhinoconjunctivitis due to sensitization to Tetranychus urticae (TU), commonly known as the red spider mite, which belongs to the Prostigmata sub-order of the Tetranychidae family, in relation to a work environment (a carnation nursery). Both prick and intradermal skin tests were positive, as well as specific bronchial challenge tests with TU extract. Specific IgE was demonstrated by RAST (Class 3). Unspecific bronchial provocation with methacholine was negative. Sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE) immunoblotting revealed the presence of seven main IgE binding proteins, the more intense bands being those appearing at 21, 17 and 15 kDa. This indicates a case of immediated type hypersensitivity to Tetranychus urticae with a clear correlation to occupational environment.

The immune response to environmental allergens depends on both genetic and environmental factors. Allergen exposure triggers the activation of allergen-specific Th2 cells in allergic patients, as well as increased Th2-type cytokine mRNA expression and eosinophil recruitment. Nevertheless, different patterns of release of cytokines could explain the heterogeneity of atopic response. In our study, 25 patients with pollinosis and 15 healthy donors were selected to characterize their release of Th2 (interleukin [IL]-4 and IL-5) and Th1 (interferon-gamma [IFN-gamma]) cytokines, both during and outside the pollen season. Peripheral blood mononuclear cells from patients and controls were isolated, cultured in the presence of phorbol-12-myristate-13-acetate plus ionomycine, and phytohemagglutinin (PHA), and cytokine release was assessed by titration in the supernatants. Both IL-4 and IL-5 showed higher levels during than outside the pollen season in pollinic patients (P<0.05) after nonspecific stimuli, whereas IFN-gamma levels were significantly lower during than outside the pollen season only after culture with PHA. Significant differences were not observed in the control group. Our results are consistent with the hypothesis that release of cytokines by peripheral blood mononuclear cells from patients with pollinosis depends on environmental exposure to sensitizing pollens, and that influence can be revealed by in vitro nonspecific stimulation. Nevertheless, the heterogeneity in results suggests that the use of mitogens to assess Th1/Th2 dominance may need careful evaluation.

No abstract

No abstract