The art of communication with children.

the human Mantoux.3 If skin testing is equivocal, or in cases of infection involving potentially vulnerable sites (such as the mastoid), when adjuvant antimycobacterial drug treatment is given, then it may be helpful to have the surgical specimen examined by the polymerase chain reaction.4 This allows differentiation between M tuberculosis and NTM infection, although the specificity and sensitivity of the polymerase chain reaction in this setting is not known. Thus appropriate antimycobacterial treatment can usually be given long before mycobacterial culture results are available at 2-3 months, and the choice of treatment does not rely solely on clinical features. DAVID BURGNER ALYSON KAKAKIOS Departments ofMicrobiology and Immunology/Infectious Diseases, Royal Alexandra Hospitalfor Children, Camperdown, NSW2050, Australia