Pattern and predictors of paradoxical response in patients with peripheral lymph node tuberculosis

Many of the patients with lymph node tuberculosis show 'Paradoxical Response" in the form of appearance of new lymph node (LN) or increase in the size of existing LN, development of new disease in other organ and worsening of the disease while on treatment. Reason behind such response in only selective patients is not clearly understood. We evaluated the pattern and predictors for paradoxical response(s) (PR) in patients with peripheral lymph node tuberculosis (TB).

Study included patients aged > 6 years with peripheral lymphadenopathy of tubercular etiology attending a tertiary care hospital from Jan 2010 to Dec 2010. PR in our study was defined as worsening of pre-existing disease or development of new lesions in a patient who has been on anti-TB therapy for at least 2 weeks.

One hundred ten patients with peripheral lymph node TB were included. Their mean age was 27.5 ± 5 years and 68 (62%) were females. PR occurred in 28 (25%) patients, at a mean onset time of 6 weeks (range 2-12 weeks) after starting anti-TB medication. Four of these 28 patients experienced PR on two occasions. Of these, 22 (79%) patients presented with enlarged lymph nodes only, 8 (29%) with new nodes at same or different site and 2 (7%) with discharging sinus. PR was observed more in younger age group (p> 0.05), female gender (p> 0.05), unilateral lymphadenopathy (p> 0.05) and those with positive AFB on initial examination (p< 0.01).

Paradoxical response in peripheral lymph node TB is associated with younger age, female gender, unilateral lymphadenopathy and those with positive AFB on initial examination.