Decreased risk for atopic disorder associated with highly hyperreactive tuberculin skin test reaction in children and adolescents.

Background: It is speculated that the exposure to Mycobacterium tuberculosis, either by infection or by Bacillus Calmette-Guérin vaccination, may inhibit the onset of atopy by the modification of immune profiles leading to a shift of T(H)1/T(H)2 balance to the T(H)1 side.

Objective: One hundred eighty-six patients hyperreactive at tuberculin skin test (TST) were examined in order to investigate the prevalence of atopic disorder, particularly referring to the association between the size of the TST induration and the prevalence of sensitization and manifest atopic disorder.

Methods: The study consisted of a family history record, patients' medical history assessment and clinical examination, skin prick test (SPT), serum total and allergen-specific IgE (sIgE) measurement and eosinophil count.