Chronic recurrent erythema nodosum due to lepromatous lymphadenitis

Leprosy is mostly confined to the skin and peripheral nervous system, although other organs including lymph nodes may sometimes be involved. A 30-year-old male presented to the OPD with fever and reddish raised lesions over the leg for 3–4 months and left inguinal region swelling for 18 months. He had developed a cough and weight loss, and after attending various hospitals had been diagnosed with tuberculosis. On examination, there were erythematous nodules and post-inflammatory hyperpigmentation mainly over the extremities and a few over the back. Sensory and motor examination were normal. On nerve examination, the left common peroneal nerve was slightly thickened. A biopsy showed non-specific inflammation. A slit-skin smear was negative for acid-fast bacilli. Fine needle aspiration cytology (FNAC) from submental, right and left inguinal swellings proved it to be a case of lepromatous lymphadenitis. The patient was started on thalidomide, methotrexate and multidrug therapy (MDT) to which he responded.

The case illustrates that lymphadenopathy in a young patient with no initial cutaneous symptoms, deformities, or sensory or motor dysfunction, does not obviously suggest leprosy, but the differential diagnosis should be kept in mind, especially in endemic areas, even in cases where the initial presentation is primarily lymphadenopathy.