In skeletal tuberculosis, the 'paradoxical reaction' refers to:

• A Worsening of neurological deficit despite adequate anti-TB treatment due to drug resistance
• B Temporary worsening of clinical or radiological signs after initiation of effective anti-TB therapy due to immune reconstitution ✓
• C Development of a new abscess at a distant site unrelated to the primary spinal lesion
• D Cross-reactivity of ATT drugs causing hepatotoxicity

Explanation

The paradoxical reaction in skeletal TB (and TB generally) refers to a temporary worsening of existing lesions or appearance of new lesions (e.g., enlarging abscess, new skin manifestations, worsening neurological signs) despite bacteriologically effective treatment. It is attributed to immune reconstitution inflammatory syndrome (IRIS) — as the pathogen burden drops, the recovering immune system mounts an exaggerated inflammatory response to residual dead bacilli and antigens. This typically occurs within 3 months of starting ATT and is not a sign of drug failure or resistance.

Reference: Maheshwari Essential Orthopaedics, 6th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.