Primary cutaneous Mycobacterium kansasii infection in a child

Mycobacteria other than Mycobacterium tuberculosis are not present in erythema induratum/nodular vasculitis: a case series and literature review of the clinical and histologic findings

Erythema induratum (EI)/nodular vasculitis (NV) is characterized by recurrent crops of tender oedematous nodules on the lower legs. A lobular panniculitis with granulomatous inflammation, vasculitis, focal necrosis and septal fibrosis is present. Mycobacterium tuberculosis DNA has been detected in some lesions by means of polymerase chain reaction (PCR). Ten cases of EI/NV were found. H&E slides were reviewed. PCR assays for M. tuberculosis and mycobacteria other than M. tuberculosis (MOTT) were performed. PCR did not reveal M. tuberculosis (0%) or MOTT (0%) DNA, with positive controls, indicating the reliability of the assays. Among the MOTT, cutaneous infections are most commonly caused by M. marinum. Subcutaneous tuberculoid granulomas may be seen with M. kansasii, M. marinum, M. scrofulaceum and M. avium complex. M. gordonae, M. szulgai and M. malmoense rarely cause cutaneous infections. M. simiae, M. gastri and M. asiaticum are probably not cutaneous pathogens. M. tuberculosis and MOTT DNA was not found in EI/NV. EI/NV has diverse aetiologies with varying pathogeneses leading to similar histologic changes. The cases analysed may not have had an infectious aetiology. However, in EI/NV, performance of PCR for MOTT as well as M. tuberculosis complex may still be beneficial, particularly in cases from immunocompromised hosts.

Cervicofacial lymphadenitis due to atypical mycobacteria: a surgical disease

Despite the increasing prevalence of cervicofacial lymphadenitis due to atypical mycobacteria (AMB) in children, the true nature of AMB infection in clinical practice is poorly understood. The purpose of our study was to define the most common signs and symptoms, and to establish a workable scheme of diagnosis and treatment. Patients fulfilling the criteria of AMB infection (i.e., clinical signs, positive cultures or polymerase chain reaction, histologic features) were included in the study. All children underwent a standard surgical procedure, depending on pretreatment and the course of the disease. Sixteen infants presented with characteristic unilateral lymphadenopathy predominantly involving the submandibular area (13/16). Eight children had been initially treated at various institutions by fine-needle puncture or incision, and 7 of the 16 patients had received antituberculous multidrug treatment for a varying length of time. Complete excision of the affected lymph nodes was the definitive treatment in all patients. Three children had transient marginal mandibular nerve paralysis that resolved within a few months in all cases. Recognition of the characteristic features of AMB adenitis may permit early diagnosis and appropriate surgical treatment.