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Psoriasis — SCE Dermatology MCQ

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HardDermatopharmacologyPsoriasisSCE Dermatology

A 33-year-old woman has chronic plaque psoriasis and has been started on Adalimumab. She develops a positive tuberculin skin test (Mantoux test) 15 mm induration during routine monitoring 6 months into treatment. Pre-treatment IGRA was negative. Chest X-ray is normal. What is the most likely explanation and appropriate action?

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Correct answer: D — Latent TB infection requiring TB prophylaxis before continuing biologic

Development of a positive Mantoux/IGRA during biologic therapy indicates possible latent TB infection acquired during treatment. BAD guidelines recommend regular TB screening during biologic therapy (typically annual IGRA or as clinically indicated). If latent TB is diagnosed during treatment, the biologic should be withheld and standard latent TB prophylaxis (Isoniazid and Rifampicin for 3 months, or Isoniazid alone for 6 months) commenced. The biologic may be restarted after at least 2 months of TB prophylaxis following specialist advice. Active TB must be excluded with sputum culture and imaging.

Reference: BAD 2020 Biologic Psoriasis Guidelines; NICE TB Guidelines