Why do I have enlarged cervical lymph nodes?
Q: The lung x-ray shows that the lung is intact & there are no symptoms of tuberculosis (TB) like cough or sputum. But there are enlarged painful cervical lymph nodes & the tuberculin test is positive? What is the likely diagnosis? Is this kind of TB considered infectious?
A:Enlarged cervical lymph nodes can have a number of causes, including viral upper respiratory infection, Infectious mononucleosis, Rubella, Catscratch disease, Streptococcal pharyngitis, Acute bacterial lymphadenitis, Toxoplasmosis, Tuberculosis/atypical mycobacterial infection, Acute leukaemia, Lymphoma, Neuroblastoma, Rhabdomyosarcoma, Kawasaki disease, etc. In our country, TB would be high on the list of causes, though tubercular lymphadenitis is usually not painful. In most patients in primary care settings, these are usually a result of benign infectious causes. Most patients can be diagnosed on the basis of a careful history and physical examination. In general, lymph nodes greater than 1 cm in diameter are considered to be abnormal. Supraclavicular nodes are the most worrisome for malignancy. A three- to four-week period of observation is advisable in patients with localised nodes and a benign clinical picture. Excisional biopsy of the abnormal node will best enable the pathologist to determine a diagnosis, and is better than fine needle aspiration cytology (FNAC). The tuberculin test is positive in the majority of the Indian population and the extent of induration, measured in mm, around the site of injection, has different cut-offs depending the population under study. Usually readings of >10 mm are taken as positive and more than 15 mm as strongly positive. However, a positive tuberculin test (Mantoux test) indicates delayed hypersensitivity and (recent) exposure to the TB bacilli, and is not synonymous with disease. There are false positive as well as false negative reactions, so a complete evaluation has to be done to correlate the tests. Extra-pulmonary forms of TB are non-infectious as a rule, unless there is a discharging sinus or some complication or associated pulmonary disease.