Mantoux Test / TST Interpretation (TB)
Tuberculin skin test (Mantoux) interpretation for latent TB infection using the NICE NG33 threshold — an induration of 5 mm or larger, regardless of BCG history.
Score interpretation
Below the NICE NG33 threshold of 5 mm.
→ Latent TB infection unlikely. A negative test does not exclude infection in immunosuppression, young children or recent exposure — follow NICE NG33 for retesting or an interferon-gamma release assay (IGRA) in these groups.
Positive at the NICE NG33 threshold of 5 mm, regardless of BCG history.
→ Assess for active TB (symptoms, chest X-ray). If active TB is excluded, offer treatment for latent TB infection: 3 months of isoniazid (with pyridoxine) and rifampicin, or 6 months of isoniazid (with pyridoxine) (NICE NG33).
Interpretation bands for the Mantoux / TST. Apply clinical judgement and local guidance.
References
- NICE NG33. Tuberculosis: prevention, diagnosis, management and service organisation. 2016 (updated 2019).
- WHO. Latent tuberculosis infection: updated and consolidated guidelines for programmatic management. 2018.
Related
Curated clinical cross-links plus same-class fallbacks.
- Tetracosactide · Synthetic ACTH (short Synacthen test)
- Urea (13C) · 13C-urea breath test
- Isoniazid · Anti-Tuberculosis Antibiotic
- Tuberculin purified protein derivative · Mycobacterial antigen for delayed-type hypersensitivity testing
- Aminosalicylic Acid (Para-aminosalicylic acid, PAS) · Antimycobacterial (Anti-tuberculosis Agent)
- Infective Endocarditis · ESC 2023 Infective Endocarditis Guidelines; NICE NG41
- Eczema Herpeticum · BAD; NICE CKS
- Suspected Bacterial Meningitis (Adult) · NICE NG240 (2024); NICE NG143 (paeds)
- Clostridioides difficile Colitis · NICE NG199 (2021); IDSA/SHEA 2021
- Returning Traveller — Fever · NaTHNaC; PHE; ESCMID 2018
- Malaria — Diagnosis & Management · PHE 2016; WHO 2023
Decision support only — verify against a current formulary, NICE, or your local guideline before clinical use.