[Non-tuberculous mycobacterial cervical adenitis in children: 2 cases]

Cervical lymphadenitis is the most common manifestation of infection with nontuberculous mycobacteria (NTM) in immunocompetent children. Nevertheless, it is poorly known by dermatologists. Its incidence, which is currently increasing since the cessation of BCG vaccination in 2007, raises several issues regarding its pathophysiology, diagnosis and management.

We report two cases of NTM adenitis: one in a 2-year-old girl vaccinated with BCG and one in an unvaccinated 22-month-old boy, in whom a misleading presentation led to delayed diagnosis. The condition progressed to fistula formation and the diagnosis was finally made on systematic cultures of lymph node samples. The time to diagnosis was 2 and 4months, respectively. The girl was treated with erythromycin for 3 weeks and with clarithromycin for 3 weeks; the boy received clarithromycin for 7 weeks and underwent complete surgical excision.

NTM adenitis preferentially affects girls under 4 years and occurs more frequently in winter and spring. First, the other differential diagnoses, including tuberculosis, must be ruled out by chest radiography. The diagnosis is oriented by the clinical picture, a positive TST and resistance to conventional antibiotics. However, it is only certified by systematic culture or PCR of lymph node biopsies, with screening for atypical mycobacteria being specified. The decrease in child protection by BCG vaccination coincides with the current increase in NTM infections, of which the most frequent is Mycobacterium avium complex (MAC) for cervical adenitis. The reference treatment is surgery. However, alternative treatments (incomplete excision, antibiotics, watchful waiting, etc.) should be considered where surgery fails or there is excessive risk of injury to a branch of the facial nerve.

Atypical mycobacterial adenitis in immunocompetent children has become an increasingly common infection since the abandonment of BCG vaccination. Improved knowledge of this disease would result in complete surgical excision at an early stage with a lower rate of aesthetic sequelae.