Childhood tuberculosis with rare dual involvement: Skin and central nervous system affected in two distinct cases

INTRODUCTION

Tuberculosis (TB) remains highly prevalent in developing countries. According to the WHO, 10.8 million new TB cases were reported globally in 2023, with 45% from SouthEast Asia.^[1] Pulmonary TB (PTB) is most common form, while extrapulmonary TB (EPTB) accounts for a smaller but significant subset. Among EPTB forms, central nervous system TB (CNS-TB) causes the greatest morbidity and mortality (42.18%),^[2] comprising 5–10% of EPTB cases.^[3] Cutaneous TB (CTB), though rare, represents 1–1.5% of EPTB cases.^[4]

We report two pediatric cases of TB with distinct dissemination mechanisms, each involving skin and nervous system manifestations in an immunocompetent host.

CASE SERIES

Case 1

A 12-year-old girl presented with new-onset intractable vomiting, nausea, headache, and diplopia for 3–4 days. Over 5 months, she developed skin lesions that became nodules that evolved into abscesses and healed with scars, repeatedly misdiagnosed as staphylococcal infection. She had lost 14% of her body weight. Examination showed puckered scars on the left leg and fluctuant swelling (3 × 4 cm) on the left forearm, without lymphadenopathy [Figure 1]. Systemic examination was normal.

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Figure 1:

Patient 1 (a-e): Axial T2-weighed image (a) and Axial T1-weighed contrast enhanced image (b) at the level of midbrain demonstrate multiple T2 hypointense ring enhancing lesions (yellow arrows) with perilesional edema in bilateral cerebral hemispheres. (c) MR spectroscopy of the lesions at Intermediate TE (135 to 144 ms) shows lipid peak at 1.3 ppm (yellow arrow). These MRI features are consistent with CNS tuberculoma. (d and e) Clinical photographs showing single erythematous plaque with central hemorrhagic crust and peripheral scaling over left forearm (d) and puckered scar over the left leg (e) (black arrow in “d and e”). Patient 2 (f-j): (f and g) Sagittal T2-weighed sequence (f) and Axial T1-weighed contrast enhanced image (g) showing lytic destruction of posterior elements of D4 and D5 vertebra with peripherally enhancing collection extending into posterior epidural space with spinal canal narrowing and compression of spinal cord suggestive of Pott’s spine. (h) Axial T2-weighed image at the level of central gyrus showing few T2 hypointense lesions (orange arrows) with mild perilesional edema in right peri-rolandic cortex. (i) Clinical image showing multiple grouped pin-point skin colored to hyperpigmented papules over abdomen, coalescing at few points. (j) skin biopsy showing dermal granulomas composed of epithelioid cells along with few multinucleated giant cells with margin of lymphoid cells at periphery (H&E stain; ×100).

Export to PPT

Given chronic skin lesions with new CNS symptoms, disseminated tubercular, fungal or bacterial infection was considered. Ultrasonography showed a hypoechoic collection, aspirated pus was acid-fast bacilli (AFB) positive. GeneXpert confirmed Mycobacterium tuberculosis (M. Tb) with rifampicin sensitivity. Cerebrospinal fluid (CSF) showed 200 cells (98% lymphocytes), elevated protein, and low glucose. Magnetic resonance imaging (MRI) brain revealed multiple ring-enhancing lesions with perilesional edema at midbrain, lateral ventricle, roof of the fourth ventricle, and cerebellar vermis. MR spectroscopy showed a lipid peak (1.3 ppm) [Figure 1]. HIV screening and chest X-ray were normal.

Disseminated TB involving skin and CNS was diagnosed. She received anti-tuberculosis therapy (ATT) with corticosteroid. Family screening found her sister positive for M. Tb lymphadenitis; she also began ATT. At 15 months, our patient had full neurological and dermatological recovery and weight gain.

DISCUSSION

Timely diagnosis of TB is vital to prevent complications. EPTB may occur through hematogenous, lymphatic, or direct spread. Commonly affected sites include lymph nodes, pleura, and bone. In both cases, skin lesions preceded neurological symptoms by months, ultimately fulfilling criteria for disseminated TB -two or more non-contiguous organ involvements.^[5]

Few case reports describe combined dermatologic and neurological TB^[6-9] [Table 1]. The first case represented tubercular gumma (metastatic abscesses), a rare CTB type characterized by subcutaneous cold abscess in immunocompetent and occasionally immunocompromised hosts [Supplementary Table 1]. The second case showed LS, a tuberculid hypersensitivity reaction with dermal granuloma on histopathology [Figure 1], and negative AFB staining with classically positive TST.

Standard ATT remains the cornerstone of treatment. Corticosteroids benefit CNS-TB by reducing edema. For spinal TB, Tuli et al. proposed the “middle path regimen” reserving surgery for static/worsening neurological status despite adequate chemotherapy.^[10] This was adapted in our second case.

These cases demonstrate different underlying mechanisms – hematogenous dissemination versus immune hypersensitivity. Early recognition of skin lesions aided by radio-pathological evidence ensures timely therapy and prevents irreversible neurological damage.

CONCLUSION

Although CTB is a rare manifestation of tuberculosis, its recognition is essential to prevent serious complications, as demonstrated by the index cases. These cases emphasize the importance of investigating CTB patients for coexisting pulmonary and extrapulmonary tuberculosis. Histopathological confirmation of suspected skin lesions, when feasible, is advised to avoid delay in diagnosis and treatment. The unique presentation of CTB alongside. CNSTB in the index cases highlights the need for thorough clinical assessment and a comprehensive diagnostic approach to identify all potential disease sites. A high index of suspicion is particularly necessary for early diagnosis when tuberculosis affects less common locations, ensuring timely and appropriate management.