Tuberculous Lymphadenitis

Tuberculous lymphadenitis is the commonest extrapulmonary form, usually involving cervical (scrofula) nodes, caused by Mycobacterium tuberculosis (and M. bovis from unpasteurised milk). It affects children, young adults and people with HIV.

• Occurs through lymphatic spread from a pulmonary focus or tonsillar infection.
• Frequently coexists with pulmonary disease and, in HIV, with disseminated disease.

Painless, firm then matted, enlarging nodes in the posterior or anterior cervical chain, sometimes bilateral, progressing to fluctuant cold abscess, overlying skin discolouration and chronic sinus.

• Constitutional symptoms in about 40 percent; more frequent in HIV.
• Differential diagnosis: reactive lymphadenopathy, lymphoma, metastatic carcinoma, HIV persistent generalised lymphadenopathy, Kaposi sarcoma, non tuberculous mycobacteria, brucellosis, cat scratch disease, toxoplasmosis, sarcoidosis, Kikuchi disease, bacterial abscess, syphilis.
• Complications: cold abscess and sinus, scarring, paradoxical enlargement on treatment, spread to other sites, airway compression, dissemination.

Tissue diagnosis is best.

• Fine needle aspiration for cytology (granulomas, necrosis), acid fast stain, Xpert MTB/RIF Ultra and culture; excisional biopsy if non diagnostic.
• Chest radiograph and sputum Xpert to look for pulmonary disease; HIV test, CD4 count, urine lipoarabinomannan.
• Ultrasound of the neck.

Medical treatment is curative; avoid incision.

• Supportive: nutrition, analgesia, counselling on possible transient enlargement, HIV care, contact screening.
• Pharmacological: 2 months of isoniazid, rifampicin, pyrazinamide and ethambutol, then 4 months of isoniazid and rifampicin (daily doses isoniazid 5 mg/kg, rifampicin 10 mg/kg, pyrazinamide 25 mg/kg, ethambutol 15 mg/kg). Extend therapy to 9 months for slow response. Pyridoxine 25 to 50 mg daily. Paradoxical reaction: continue tuberculosis drugs, aspirate fluctuant nodes, and give prednisolone 1 mg/kg daily for 2 to 4 weeks then taper over 4 weeks if severe. HIV: antiretroviral therapy within 2 weeks if CD4 is under 50 and within 8 weeks otherwise; dolutegravir 50 mg twice daily during rifampicin.
• Procedures: repeated needle aspiration of fluctuant nodes through healthy skin; surgical excision for persistent or drug resistant nodes only; avoid incision and drainage (sinus risk).
• Special groups: children, weight band dosing and exclude M. bovis; pregnancy, first line regimen with pyridoxine; HIV, expect paradoxical reactions; drug resistant disease, specialist regimen.
• Red flags: rapidly enlarging hard node, fixed nodes, weight loss with night sweats, airway compression, sinus formation, no regression at 2 months, suspicion of lymphoma.
• Follow-up: monthly review; node size recorded; biopsy if growth persists after 3 months of treatment.