Scrofula revisited: an update on the diagnosis and management of tuberculosis of superficial lymph nodes.
Lymph node tuberculosis is a disease of great antiquity. It is the commonest form of extra-pulmonary tuberculosis, and is probably the commonest cause of chronic lymphadenitis in children. Even after the advent of effective chemotherapy for tuberculosis, it still poses considerable problems in diagnosis and management. The disease usually presents as a painless lymphadenopathy of the superficial lymph nodes of insidious onset, which may proceed to abscess and sinus formation if neglected. Cervical nodes are most commonly affected, but multiple node involvement is common. Differential diagnosis include other infections, neoplasia, congenital conditions in the head and neck and rarely, drug reactions. Diagnosis, whenever feasible, should be made on the basis of histological evidence after lymph node biopsy. Diagnosis made on clinical grounds has poor specificity and will result in a great degree of over diagnosis. Recently, the role of fine needle aspiration cytology as an initial screening procedure has been recognized. The Tuberculosis Research Centre carried out the first clinical trial which established the efficacy of short course chemotherapy in the treatment of childhood lymph node tuberculosis. In 168 children with biopsy confirmed lymph node tuberculosis treated with an intermittent six month regimen, the cure rate after five years was 95%. The Revised National Tuberculosis Control Programme recommends that patients with lymph node tuberculosis (Category 3) should be treated with rifampicin and isoniazid three times a week for six months, with pyrazinamide for the first two months.