Table 6– Possible reasons for a false-negative tuberculin skin test (generally D)
Age <6 months
Age >65 yrs 137
Cellular immune defects (e.g. HIV infection, AIDS and lymphoproliferative disorders)</emph>
Acute or recent severe viral infection (e.g. rubella 138, measles 139, 140 and mononucleosis 140) and scarlet fever 140
Immunisation with live vaccines within the past 6 weeks (e.g. measles, poliomyelitis, yellow fever, mumps 141 and rubella 142</emph>)
Severe debilitating diseases (e.g. malignancies 143</emph>)
Systemic high-dose corticosteroid therapy (>15 mg prednisolone equivalent) or treatment with immunosuppressants
Advanced pulmonary tuberculosis 133, 144, central nervous system tuberculosis and disseminated tuberculosis 145
Sarcoidosis 146
Malnutrition 147
Window period for manifest immune response to infection with Mycobacterium tuberculosis
Application errors (incomplete or subcutaneous tuberculin injection, incorrect quantity of tuberculin, inadequate storage of tuberculin)
Reading errors (too early or too late)