A Case of Metastatic Cutaneous Tubercular Abscess with Concomitant Central Nervous System Tuberculoma in an Indian Adolescent Girl

CASE DESCRIPTION

An 11-year-old girl, coming from a village near Coimbatore and belonging to a lower socioeconomic status, was brought by her mother with complaints of swelling near the right elbow and right ankle for a duration of 2 months. The child had been apparently normal until 4 months before the presentation, after which she developed swelling on the left side of her neck, which required drainage and treatment with oral medications at a private hospital. Later, the child began to develop swelling of a similar type near the right arm, right ankle, right elbow, and lower back. These swellings were initially painless, but gradually increased in size with restriction of movement in those joints, along with pus discharge. The child also had a history of loss of appetite and weight loss (approximately 10 kg over 2 months). There was no history of fever, respiratory complaints, skin diseases, or trauma. There was no history of contact with TB-infected persons or similar complaints among other family members. Her immunization history was complete, and she was a healthy adolescent studying in the 6th standard, with no history suggestive of chronic illness or immunodeficiency.

General examination revealed a lean girl with normal vitals. The BCG scar was present. Systemic examination was unremarkable, and her initial neurological examination was normal. Dermatological examination revealed multiple well- to ill-defined hyperpigmented scaly plaques on the bilateral upper limbs and lower limbs, suggestive of nutritional dermatosis. There was a diffuse tender swelling in the right ankle with a 1 × 1 cm ulcer with undermined edges and serous discharge on the medial aspect of the ankle (Fig. 1). The swelling was warm, and she had pain during mobility of the joint. Other swellings of 9 × 5 cm over the right elbow, 4 × 4 cm over the gluteal region, and 3 × 3 cm on the upper back did not show any signs of inflammation (Fig. 2).

Laboratory investigations showed anemia, elevated ESR (40 mm/hour), and CRP (93 mg/L). Renal function was normal, and liver function showed hypoalbuminemia. Pus from the ankle sinus was positive for Klebsiella growth and negative for acid-fast bacilli. Mantoux was negative. Sputum cartridge-based nucleic acid amplification test (CBNAAT) was negative for tuberculosis. Chest X-ray was normal, HIV ELISA was negative, and ultrasound of the swellings showed internal fat stranding suggestive of an abscess.

The child was initially treated with culture-susceptible antibiotics, but there was no response. Since there was a strong suspicion of tuberculosis, under sterile precautions, incision and drainage of pus from the elbow abscess was performed by the pediatric surgery team, and pinkish pus was drained. The pus was sent for molecular diagnosis of M. tuberculosis by CBNAAT, which turned out to be positive (Fig. 3). Since rifampicin sensitivity was present, the child was started on antitubercular drugs—HRZE (isoniazid, rifampicin, pyrazinamide, and ethambutol) for 2 months and HRE for 10 months—after thoracic medicine consultation and was discharged with a plan for periodic follow-up.

Two weeks after discharge, the child presented with an episode of focal seizures and altered sensorium, for which neuroimaging was done, uncovering the presence of CNS tuberculoma (Fig. 4). Since the neurological symptoms manifested after starting the therapy, immune reconstitution inflammatory syndrome (IRIS) was suspected, and the child was started on systemic corticosteroids along with antiepileptics. Steroids were tapered and stopped over 6 weeks. Antiepileptics were tapered and stopped over 2 years. Skin lesions healed with no further abscess formation. There were no new neurological complaints. Antituberculosis therapy (ATT) was continued for a period of 12 months, and the child regained the lost weight. The treatment was labeled as successfully completed (Fig. 5).