immunity since colonization of the upperrespiratory tract (e.g., with Neisseria meningitidis, Haemophilus in¯uenzae, or Streptococcus spp.) occurs early in life, resulting in 1/4 individuals being temporarily affected. It is known that irritating stimuli, such as LPS, can convert a tolerizing immune response into an allergic IgE-based response (4). Intriguingly, we recently found that neisserial IgA1 protease that is secreted in conjunction with the cross-reacting a-proteins is a potent inducer of proin¯ammatory cytokines (Lorenzen et al., submitted). Therefore, colonization with N. meningitidis and related pathogens might trigger allergic responses against otherwise harmless proteins. Furthermore, structural similarity with host proteins (Fig. 1) may stimulate the allergic memory over the winter season. The nasopharyngeal carriage of microbial pathogens in children with a history of atopic diseases (5) and the increased development of allergic symptoms in meningococcal stockvaccinated patients (6) support the signi®cance of our observations. However, the clinical relevance of our ®ndings remains to be established. References 1. Smith PM, Ong EK, Knox RB, Singh MB. Immunological relationship among group I and V allergens from grass pollen. Mol Immunol 1994;31:491±498. 2. Schenk S, Breiteneder H, Susani M, et al. T-cell epitopes of Phl p I, major pollen allergen of timothy grass (Phleum pratense): evidence for cross-reacting and non-cross-reacting T-cell epitopes within grass group I allergens. J Allergy Clin Immunol 1995;96: 986±996. 3. Mohapatra SS, Mohapatra S, Yang M, et al. Molecular basis of cross-reactivity among allergen-speci®c human T-cells: T-cell receptor V usage and epitope structure. Immunology 1994;81:15±20. 4. Holt PG, Britten D, Sedgwick JD. Suppression of IgE-responses by antigen inhalation: studies on the role of genetic and environmental factors. Immunology 1986;60:97±102. 5. Sorensen CH, Kilian M. Bacterium-induced cleavage of IgA in nasopharyngeal secretions from atopic children. APMIS 1984;92:85±87. 6. Borysova L, Tomsikova M, Kuzenska P, Burian V. Allergisation of the organism by Neisseria meningitidis. II. Studies concerning the results of vaccine therapy in diseases carried by bacterial allergy. Z Bakt Hyg . We present a 34-year-old woman with a personal background of smoking and simple chronic bronchitis with bronchial hyperreactivity. Diagnosed with pulmonary tuberculosis, she began triple tuberculostatic treatment with isoniazid, rifampicin, and pyrazinamide. After 2 months, she visited the hospital with a severely pruritic urticariform cutaneous eruption; treatment was started with chlorpheniramine, and pyrazinamide was discontinued because the treatment had been completed. One week later, she was admitted to the emergency department because of a worsening of the eruption, with edema in the face and neck, purpuric lesions in the lower extremities, cutaneousmucous icterus, lymphadenopathy, asthenia, and a fever of 388C. The emergency analysis was as follows. Leukocytes numbered 11.5310...
