Atypical mycobacteriosis in children: a diagnostic and therapeutic challenge.

Atypical mycobacteriosis (AM) is a rare disease, which is caused by an infection with mycobacteria other than tuberculosis (MOTT). In children, the cervical lymph nodes are frequently affected. MOTT are a pathogen or facultative pathogen environmental germs, which can affect otherwise healthy individuals. The diagnostic and therapeutic management is often challenging. Currently, there are only few data published about the systematic investigation and therapy of children with AM. In a retrospective study, 29 children with AM were evaluated. The clinical records of these patients were reviewed and analyzed along with the results of histopathological and microbiological findings. The clinical parameters were correlated to patients' therapy and clinical follow-up. 29 otherwise healthy and immunocompetent children (18 girls, 11 boys, average age of 3.5 years, range 1.5-9.5 years) with AM of the head and neck region have been evaluated. Clinically, all patients were admitted with a swelling of cervical lymph nodes and discoloration of the overlaying skin. In five patients, an abscess formation of the lymph nodes occurred. Ultrasound examinations typically revealed a hypoechoic mass with central necrosis and intralesional septa. Histologically, epithelioid granuloma with caseating necrosis was described in any case. Germ identification by either microbiological culture or PCR was successful in 20 cases, with Mycobacterium avium and Mycobacterium intercellulare being the most frequent germs. In all patients, lymph nodes were surgically removed. In a clinical follow-up of at least 18 months, a recurrence occurred in five cases. Diagnosis of atypical mycobacteriosis is often difficult and challenging, since clinical appearance is unspecific and MOTT can only be identified microbiologically or by PCR in about two-thirds of cases. Therefore, a close cooperation between clinician, pathologist, and microbiologist is required. Therapeutically excision of all affected lymph nodes is recommended. Alternative or concomitant medical treatment with tuberculostatics is indicated in particular cases, i.e., recurrence, persistence or systemically lymph node involvement.