Table 1.

Extrapulmonary non-tuberculous mycobacterial (EP-NTM) disease – risk factors and clinical manifestations.

Risk factor	Causative organism	Clinical manifestations
Inoculation
Fish tank +/- swimming pool granuloma	M. marinum	A slow growing, inflamed, erythematous nodule or plaque. Often painful and ulcerates over time. Associated with cellulitis
Buruli ulcer	M. ulcerans	Initially painless nodule that develops into large ulcers with a discoloured white/yellow base. Most commonly affects upper or lower limbs.
Lymphadenitis	M. avium complexa	Lymph node enlargement, most often cervical (usually affects children)
Skin and soft tissue infections
Keratitis, choroiditis, endophthalmitis	M. fortuitum M. chelonae M. abscessus	Erythematous and nodular lesions to the skin, epiphora, purulent discharge and proptosis
Cosmetic surgery		Wound dehiscence; erythema and induration; nodule and abscess formation
Post-traumatic wound infections
Musculoskeletal infections
Tenosynovitis	M. avium complex*	Gradual and insidious onset of enlargement of the tendon and synovium with persistent slow progression. Rarely complicated by involvement of underlying muscles, bone structures and/or joint spaces
Osteomyelitis	M. abscessus M. fortuitum M. chelonae	Usually observed following trauma or joint replacement. Most commonly associated with disseminated NTM infection(s) and secondary to immunosuppression. Vertebral involvement – bone pain, neuropathic pain and neurological symptoms
Iatrogenic and post-procedural infections
Joint replacement	M. abscessus, M. fortuitum M. chelonae	Gradual onset of joint infection with swelling, erythema and fevers
Prosthetic heart valve	M. chimaera M. fortuitum M. chelonae M. abscessus	Infective endocarditis – fever, weight loss, malaise, anaemia, pancytopenia, valve insufficiency on echocardiogram
Cardiac surgery	M. chimaera	Overlying sternal wound infection with wound dehiscence; erythema and induration; nodule and abscess formation
Peritoneal dialysis-associated infection	M. fortuitum M. chelonae M. abscessus	Peritonitis – abdominal pain, nausea, vomiting, pseudo bowel obstruction. Rarely complicated by loculated ascites and formation of abdominal adhesions
Disseminated disease
HIV infection	M. avium complexa	Disseminated disease will usually present as persistent nonspecific symptoms including fever, night sweats, malaise and weight loss. Associated with respiratory (dry cough, dyspnoea) and/or abdominal (pain, diarrhoea, malabsorption) symptoms. Patients often have an associated pancytopenia and abnormal liver function tests indicating dissemination to bone marrow, liver and other organ systems
Post solid organ transplantation

^aM. avium complex refers to a group of multiple NTM species which includes M. avium, M. intracellulare and M. chimaera