Mycobacterium szulgai: an unusual cause of disseminated mycobacterial infections

Cutaneous Mycobacterium szulgai infection in a patient with Cushing's syndrome: a case report and literature review

BACKGROUND

Opportunistic infection is an under-recognized complication of Cushing's syndrome, with infection due to atypical mycobacterium rarely reported. Mycobacterium szulgai commonly presents as pulmonary infection, with cutaneous infection seldom reported in the literature.

CASE PRESENTATION

48-year-old man with a newly-diagnosed Cushing's syndrome secondary to adrenal adenoma presented with a subcutaneous mass on the dorsum of his right hand, was diagnosed with cutaneous Mycobacterium szulgai infection. The most likely source of the infection was through minor unnoticed trauma and inoculation from a foreign body. The patient's Cushing's syndrome, high serum cortisol levels and secondary immune suppression facilitated mycobacterial replication and infection. The patient was successfully treated with adrenalectomy, surgical debridement of cutaneous lesion, and a combination of rifampicin, levofloxacin, clarithromycin, and ethambutol for 6 months. There were no signs of relapse one year after cessation of anti-mycobacterial treatment. A literature review on cutaneous M. szulgai infection to further characterize the clinical characteristics of this condition, identified 17 cases of cutaneous M. szulgai infection in the English literature. Cutaneous M. szulgai infections with subsequent disease dissemination are commonly reported in immunocompromised hosts (10/17, 58.8%), as well as in immunocompetent patients with a history of breached skin integrity, such as invasive medical procedures or trauma. The right upper extremity is the most commonly involved site. Cutaneous M. szulgai infection is well controlled with a combination of anti-mycobacterial therapy and surgical debridement. Disseminated infections required a longer duration of therapy than localized cutaneous infections. Surgical debridement may shorten the duration of antibiotics.

CONCLUSIONS

Cutaneous M. szulgai infection is a rare complication of adrenal Cushing's syndrome. Further studies are needed to provide evidence-based guidelines on the best combination of anti-mycobacterial and surgical therapy for managing this rare infective complication.

Disseminated Mycobacterium szulgai infection in a patient with anti-interferon-gamma autoantibodies

Incidence of nontuberculous mycobacterial infections has increased during the past decades. Disseminated infections are relatively rare and associated with immunocompromised status. We report a case of disseminated Mycobacterium szulgai infection of cervical lymphadenitis and pulmonary involvement with positive anti-interferon-gamma autoantibodies. The patient was successfully treated with rifampin, ethambutol, and clarithromycin. The case reports and series through search engines of Pubmed and Google with the keyword of disseminated infection of M. szulgai were reviewed. Fifteen patients of disseminated M. szulgai infection were reviewed and included. DisseminatedM. szulgaiinfection involves bone, skin and lymph node more common instead of pulmonary involvement, and most are associated with immunocompromised status with neoplastic hematologic disorders. In patients with disseminated M. szulgai infection, long term anti-mycobacterial agents are necessary. Most patients will respond to rifampin and ethambutol combination regimens.

Mycobacterium avium-intracellulare pulmonary infection complicated by cutaneous leukocytoclastic vasculitis in a woman with anorexia nervosa

A 53-year-old Caucasian woman with a history of anorexia nervosa developed a bilateral lower extremity rash comprised of palpable red to violaceous, sub-centimeter papular lesions that increased in quantity rapidly. She also noted a 2-month history of non-productive cough. Imaging modalities revealed a thin-walled cavitary lesion in the right lung apex and scattered nodular opacities. Acid fast bacilli (AFB) were found in sputum and subsequently identified by culture as Mycobacterium avium-intracellulare (MAI). Punch biopsies of her skin lesions yielded a histological diagnosis of small-to-medium vessel vasculitis. Stains and cultures for organisms were negative. Her skin lesions resolved quickly after the initiation of antimicrobial therapy for MAI. Hypersensitivity vasculitis associated with an atypical mycobacterial infection is unusual. The postulated underlying mechanism is the deposit of immune complexes and not the bacillus itself. While cutaneous leukocytoclastic vasculitis (CLV) due to MAI is certainly a rare entity, it should be entertained in patients with vasculitic skin lesions and a concomitant pulmonary disease.

Mycobacterium szulgai chronic multifocal osteomyelitis in an adolescent with inherited STAT1 deficiency

We report a 17-year-old patient with inherited STAT1 deficiency, who was diagnosed with Mycobacterium szulgai chronic multifocal osteomyelitis and responded well to the therapy with ethambutol, rifampicin and azithromycin. Seven other reported cases of M. szulgai osteomyelitis are reviewed. This is the first description of M. szulgai osteomyelitis in an adolescent with a primary immunodeficiency.