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Latent TB and Biologics — SCE Dermatology MCQ

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ModerateDermatopharmacologyLatent TB and BiologicsSCE Dermatology

A 30-year-old woman with psoriasis has recently been diagnosed with latent TB on IGRA screening before starting a biologic. How should latent TB be managed before commencing biologic therapy?

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Correct answer: E — Start latent TB treatment (Isoniazid for 3-6 months or Rifampicin for 3 months); the biologic can be started 1-2 months after commencing TB treatment

Latent TB must be treated before starting biologic therapy to prevent reactivation (particularly relevant for anti-TNF agents which carry the highest reactivation risk). BAD guidelines recommend: starting latent TB treatment (Isoniazid 300 mg daily for 6 months, or Rifampicin for 3 months — guided by local TB service), then commencing the biologic after 1-2 months of TB treatment (allowing adequate initial TB suppression). This timing balances the urgency of treating psoriasis against the risk of TB reactivation. IL-17 and IL-23 inhibitors have lower TB reactivation risk than anti-TNF agents but screening is still mandatory. TB service co-management is essential.

Reference: BAD 2020 Biologic Guidelines; NICE NG33 TB