title: Vaccine allergy and pseudo-allergy.
abstract: Allergic and pseudo-allergic reactions to vaccines frequently involve the skin, and can be generalized systemic symptoms (urticaria/angioedema, serum sickness, flares of eczema) or localized at the sites of vaccination (persistent nodules, abcesses, granulomas). Diagnosis of Arthus-type reactions is based on clinical history and specific IgM/IgG anti-toxoid determination. For other local reactions, diagnostic value of non-immediate responses in skin tests varies with clinical symptoms and substances involved. Immediate responses in skin tests and specific IgE determination have good diagnostic and/or predictive value in anaphylaxis and immediate/accelerated urticaria/angioedema to toxoid-, pneumococcus-, and egg- and gelatin-containing vaccines. Diagnosis of reactions to dextran in BCG is based on specific IgM/IgG determination. Most non-immediate generalized reactions result from non-specific inflammation, except for gelatin-containing vaccines, but the diagnostic value of immuno-allergological tests with the vaccines and gelatin are controversial. Withholding booster injections is advised if specific IgM/IgG levels are high. If the levels are low, sequential injections of vaccines containing a single vaccinating agent are usually tolerated. However, injections of the vaccine should be performed using a " desensitization " procedure in patients reporting anaphylaxis and immediate/accelerated urticaria/angioedema.
authors.affiliation: Pediatric Pulmonology & Allergy Service, Sick Children Hospital, 149, rue de Sèvres, 75015-Paris, France. pneumo.allergo@nck.ap-hop-paris.fr
authors.forename: Claude
authors.initials: C
authors.lastname: Ponvert
authors.forename: Pierre
authors.initials: P
authors.lastname: Scheinmann
mesh_terms: D000707:Anaphylaxis / Q000209:etiology; D000799:Angioedema / Q000209:etiology; D001183:Arthus Reaction; D003911:Dextrans / Q000009:adverse effects; D004342:Drug Hypersensitivity / Q000209:etiology; D005780:Gelatin / Q000009:adverse effects; D006801:Humans; D006967:Hypersensitivity / Q000175:diagnosis / Q000209:etiology* / Q000517:prevention & control; D007159:Immunologic Tests; D010047:Ovalbumin / Q000009:adverse effects; D014581:Urticaria / Q000209:etiology; D014612:Vaccines / Q000009:adverse effects*
chemical_list: D003911:Dextrans; D014612:Vaccines; D005780:Gelatin; D010047:Ovalbumin