Which clinical history findings are characteristic of Mycobacterium avium-intracellulare (MAI) infection?

Updated: May 27, 2021
  • Author: Jaggi Rao, MD, FRCPC; Chief Editor: Dirk M Elston, MD  more...
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It is important to consider cutaneous infection with Mycobacterium avium-intracellulare (MAI, or MAC) in patients with antibiotic-resistant cellulitis, nonhealing nodules, and ulcers, as well as in patients who are immunosuppressed with evidence of disseminated MAI (DMAI) infection.

Data on skin and soft-tissue infection caused by nontuberculous mycobacteria in Taiwan (1997-2008) suggest that MAI is an important pathogen. [8]

Any history of the introduction of a foreign object (eg, needle, splinter) should be sought if MAI infection is suspected. Fever and other constitutional symptoms are generally absent. Skin abscess and sinus tracks may be present. Sporotrichoid spread of cutaneous MAI complex infection can occur. [9]

Patients with MAI cervical adenitis may present with an indolent course of a unilaterally expanding mass in the neck, such as enlarged submandibular or submaxillary nodes.

Cutaneous disease

Cutaneous MAI infection should be suspected when an individual who is immunocompromised presents with obscure skin lesions. Additional symptoms may suggest disseminated disease, including fatigue, fever, diarrhea, weight loss, back or bone pain, shortness of breath, and/or cough. Other clinical manifestations include involvement of organs such as the lungs, lymphatic system, and musculoskeletal system. [1]

Nutritional status impacts susceptibility to MAI infection; a patient with anorexia nervosa who also developed MAI and leukocytoclastic vasculitis is notable but not altogether surprising. [10]

Cutaneous MAI infection has also been reported to mimic histoid leprosy in patients with HIV infection or acquired immunodeficiency syndrome (AIDS). [11, 12] Subcutaneous and muscular abscesses due to MAI can occur as a manifestation of immune restoration in patients with AIDS. [13] Other reports include a case mimicking sarcoid [14] and a case reporting a cutaneous pseudotumor related to MAI. [15]

Primary cutaneous MAI infection is most often the result of traumatic inoculation, although a specific history of trauma is generally absent. Patients may describe the development of a single nodule or multiple nodules progressing over time into ulcerative lesions with or without serosanguineous exudates. Painful subcutaneous nodules and ulcers that occur on the extremities and the trunk may be noted. Lesions may be present in multiple stages of development, and nodules have been described as both flesh colored and purple-red.

MAI has also been noted to be associated with several diverse pathologies. Teraki et al noted that MAI can be associated with Sweet syndrome. [16] Henoch-Schönlein purpura associated with pulmonary MAI complex infection has also been noted. [17]

MAI can also be associated with osteomyelitis. Primary nontraumatic MAI complex osteomyelitis of the distal phalanx has occurred. [18] Multifocal osteomyelitis caused by nontuberculous mycobacteria in patients with a genetic defect of the interferon-gamma receptor has also been noted.

Murdoch and McDonald reported MAI cellulitis occurring with septic arthritis after joint injection. [19]

After initiating treatment for MAI complex involving osteomyelitis, DRESS syndrome has been reported to occur. [20]

MAI olecranon bursitis resolving without surgical or antimicrobial intervention has been noted to occur. [21]

A 2018 review of 30 cases found that patients had associated medical histories of organ transplantation, hemodialysis, underlying malignancies, and pulmonary tuberculosis. [1]

A 2021 case found that MAI was associated with concurrent small bowel obstruction, which indicates the possibility of MAI infection in cases of postoperative abdominal pain after surgery for small bowel obstruction. [22] Another report from 2020 found extranodal MAI infection, likely from hot tubs, in two immunocompetent children, with primary involvement in pulmonary and urinary systems. [23]

A 2020 review found that MAI is an emerging pathogen in dog breeders with hereditary immunodeficiencies, particularly those who breed dogs with a predisposition for MAI infection (eg, Miniature Schnauzers, Basset Hounds). The review purports the zoonotic potential of canine MAI infections to be transmitted to immunocompromised human patients. [24]

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