Bacille calmette-Guérin (BCG) associated lymphadenitis

Abstract

Background: Excluding local reaction, regional lymphadenitis is the most common adverse events after BCG vaccination. It is the development of ipsilateral regional lymph node enlargement following BCG vaccination. Some progress to suppuration. If left untreated, suppurative lymphadenitis frequently ruptures with sinus formation, ending in prolonged course of illness and scaring. Objective: To describe the clinical features and outcome of children with suppurative lymphadenitis after BCG vaccination. To identify factors associated with the duration of healing and scarring formation. Method: Patients diagnosed suppurative BCG lymphadenitis in a tertiary paediatric centre from January 2004 to April 2011 were identified. Data on demographics, clinical features, treatment received and outcomes were retrieved from medical records. Results: There were 15 cases of BCG suppurative lymphadenitis during the period. 11(73.3%) were males. All had their BCG vaccinated at birth. The mean age of presentation was 5.8±6.6 months (median 3 months). All presented with a solitary swelling over ipsilateral axilla(80%) or supraclavicular region without systemic symptom. The mean size of lymph nodes were 2.1cm±0.8cm times 1.8cm±0.8cm. All except 1 had a normal chest X-ray. The mean total white cell counts and mean lymphocyte counts were 13.0x109/L and 7.3x109/L respectively. 7/13(53.8%) patients were smear positive for acid-fast bacilli and 2/13(15.4%) were culture positive for Mycobacterium bovis. 12(80%) patients had single needle aspiration performed while the other 3 patients did not receive intervention. No patient required surgical excision. 5(33.3%) patients had spontaneous rupture and discharge. 2(13.3%) patients had sinus formation with persistent discharge for long duration. All patients completely healed subsequently. The mean duration of complete healing was 4.5 ± 1.7 months. 8/13(61.5%) patients had subsequent scarring. The duration of healing was not associated with sex, age, time since BCG vaccination, white cell and lymphocyte count, site of lymph node, size of lymph node, presence of spontaneous rupture, sinus formation or needle aspiration. The size of lymph node at presentation was significantly larger in patients with scarring (2.4±0.8cm vs. 1.3±0.4cm, p=0.026). On the other hand, sex, age, site of lymph node, white cell and lymphocyte count, presence of sinus formation, spontaneous rupture, needle aspiration and duration of healing showed no correlation with scarring. Conclusion: Suppurative lymphadenitis is not an uncommon complication of BCG vaccination. The diagnosis is clinical and should be suspected in children present with ipsilateral axilla, occasionally supraclavicular lymph node enlargement with history of BCG vaccination. A chest X-ray is recommended for all patients while tuberculin skin test has no diagnostic use. The low positive microbiological yield in aspirate highlights that negative smear or culture does not rule out the diagnosis. Needle aspiration is safe and is the main stay of treatment. Surgical excision is reserved for those who failed repeated needle aspirations. The size of lymph node was significantly associated with subsequent scarring formation.