Anaphylaxis is a serious generalized or systemic hypersensitivity reaction that is rapid in onset and potentially fatal.
Diagnosis can be made if it is acute in onset of minute to several hour
duration that involves the skin, mucosal tissue or both plus having
signs & symptoms either respiratory or cardiovascular compromise.
It involves immunological response with IgE, IgG or immune complexes.
Non-immunological mechanisms are also involved and termed as nonallergic
anaphylaxis that is relatively uncommon in children.
Protracted, severe anaphylaxis are reactions occurring up to 32 hours despite aggressive management.
Among adolescents who have only received diphtheria, tetanus toxoids, acellular pertussis (DTaP) vaccines in childhood, tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccine provides moderate protection against pertussis during the first year and then wanes rapidly thereafter.
Despite the prevalence of corticosteroid use in infants with bronchiolitis, data on its efficacy is insufficient. In this study, oral dexamethasone was compared with placebo in the treatment of bronchiolitis.