A 48-year old man presented with multifocal nodules of variable size arranged in a sporotrichoid-like manner on the right arm, the dorsum of the digit IV, the left arm, the right side of his back, the knees and a partly circumscribed erythematous plaque on his back (Figure 1A-D). The lesions persisted for already 2 months without any other symptoms.
At two occasions skin biopsies from several lesions (dorsum of right digit IV, dorsum of the right hand, the right elbow, and the patients back) were initiated and subjected in parallel to histopathological and microbiological examinations. They revealed caseating epitheloid cell granuloma in the dermis with a marginal zone of lymphocytes and a subepidermal lymphohistiocytic infiltrate with perivascular accentuation (Figure 1E, F). By PAS-, Fite-, Ziehl-Neelsen and Auramin staining no acid fast bacilli were detected. Borrelia-specific IgM and IgG and tuberkulin skin test were negative. Microbiological cultures showed twice growth of M. haemophilum from independent lesions on the right hand taken about 8 weeks apart. Interestingly, M. kansasii was recovered from another lesion on the right elbow indicating a mixed infection.
Mycobacteria-specific liquid and solid cultures were performed by using the automated BACTEC MGIT 960 system (Becton Dickinson) at 36 C and Lowenstein-Jensen Agar (LJA) at 24 C, 30 C, and 36 C. Growth of acid fast bacilli was detected from LJA at 30 C supplemented with hemin discs. First, culture isolates were identified as NTM due to the absence of an amplicon by a M. tuberculosis-specific gyrB PCR and were then further verified by the GenoType Mycobacterium DNA strip technology (Hain Lifescience, Nehren, Germany), namely the GenoType Mycobacterium CM and AS assay (CM, common mycobacteria; AS, additional species). The GenoType Mycobacterium CM assay enables the simultaneous identification of several species, including those of the M. tuberculosis complex, the M. avium complex, M. abscessus, M. kansasii and M. chelonae etc. The Mycobacterium AS test provides the identification of rarely found species, such as M. simiae, M. haemophilum, and M. mucogenicum. In case of M. haemophilum, Mycobacterium CM assay revealed a banding pattern specific for the M. haemophilum-M. nebraskense-M. malmoense-M. palustre group. Further species differentiation was done with the AS assay that showed positivity for M. haemophilum and M. nebraskense but not for M. malmoense or M. palustre. The growth requirement for hemin indicated the presence of M. haemophilum. Nevertheless, species identification of M. haemophilum was confirmed at the National Reference Center for Mycobacteria in Borstel (Germany). M. kansasii was recovered with the Bactec MGIT 960 and identified with the GenoType Mycobacterium CM assay.
Thus, culture positive lesions were all from the right body site, while no co-infection of a single lesion was found. Interestingly, the patient was working as a scaffolder having potential exposure to diverse environmental habitats while touring around Europe. Further, he is aquarist but reports to usually wear gloves during cleaning his aquarium.
Interestingly, in the patient's history a selective IgA-deficiency was documented since childhood. His mother also suffered from IgA-deficiency. Since infancy human immunoglobulin (Beriglobin ) was administered, but due to his frequent travel activities the substitution was realized irregularly. Serum IgA level was 1.8 (07-4.0) mg/ml under substitution with Beriglobin . Biochemical laboratory parameters were within normal ranges except for serum protein electrophoresis with albumin of 57.2% (59-70.6) and beta globulin of 14.9% (7.3-12.2). ASL, AST, ACE, ANA, and ENA tests were unremarkable. Besides multiple cutaneous lesions there was no evidence for lymphadenopathy or systemic infection with M. haemophilum/M. kansasii by using abdominal ultrasound, thorax X-ray, and thoraco-abdominal computer tomography imaging. Mycobacterial sputum cultures were negative as well. Empirical triple treatment with clarithromycine 2 x 500 mg/d, rifabutine 1 x 300 mg/d and ethambutol 1 x 20 mg/kg body weight/d was initiated. This regime was given for 6 months, while a complete clinical remission of skin lesions was seen within 4 months. Finally, two years after his initial presentation the patient is still healthy.