Erythema nodosum associated with reactivation tuberculous lymphadenitis (scrofula).

A 73-year-old African American female presented to our clinic with painful lower extremity lesions of 2 weeks duration. She was in her usual state of health until 3 months prior to presentation when she reported symptoms of fatigue and weakness. She also noticed an enlarging mass on the left side of her neck. She denied fevers, chills, night sweats or cough. Her symptoms were unresponsive to a course of oral dicloxacillin. The neck mass enlarged over 8 weeks and she was referred to our institution for evaluation. CT scan of the neck showed an enlarged lymph node. Ten days prior to her presentation in dermatology, a fine needle aspirate of the enlarging lymph node revealed necrotizing granulomas. Tissue was sent for routine mycobacterial and fungal cultures. Routine blood work, chest radiograph, and a tuberculin skin test were also performed. At the time of her dermatology visit she described the development of multiple new painful, non-pruritic lesions, bilaterally on the lower extremities. She also reported a red crusted area that appeared at the site of her tuberculin test that was placed subsequent to the development of her lower extremity lesions. Her past medical history was significant for Parkinson's disease, hypothyroidism and hypertension. Her current medications included l-thyroxine, estrogen and diltiazem. Her travel history was only remarkable for a trip to Jamaica the previous spring. She was born and raised in Haiti. She reported a history of a positive tuberculin skin test 20 years ago, but received no therapy. Physical examination revealed a 2 x 3 centimeter firm, nontender left lateral neck mass (Fig. 1). Her right forearm revealed an erythematous, ulcerated, indurated plaque 1.5 cm in diameter (Fig. 2.). Her lower extremities revealed tender 0.5 to 1 cm erythematous nodules below the knees bilaterally (Fig. 3). A punch biopsy of a lower extremity nodule revealed a mild pervisacular dermal infiltrate. Within the subcutaneous tissue there was septal widening. There was also a lymphohistiocytic infiltrate with a slight admixture of neutrophils within the septa of the fat lobules. There was no evidence of necrotizing vasculitis or collagen necrosis. An acid-fast stain was not performed. The histologic findings were consistent with a diagnosis of erythema nodosum. Her laboratory evaluation including CBC, electrolytes, thyroid studies, angiotensin converting enzyme level and chest radiograph were normal. Approximately 1 week after her dermatological evaluation, the fine-needle aspirate culture grew Mycobacterium tuberculosis. A diagnosis of tuberculous lymphadenitis associated with erythema nodosum was confirmed. The patient was started on quadruple therapy of isoniazid, rifampin, ethambutol and pyrazinamide. Her lower limb skins lesions rapidly resolved over the subsequent month and her neck mass also diminished in size. She completed 6 months of antituberculous therapy with complete resolution of her lymphadenopathy.