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Mycobacterium Avium-Intracellulare Clinical Presentation

  • Author: Janak Koirala, MD, MPH, FACP, FIDSA; Chief Editor: Michael Stuart Bronze, MD  more...
Updated: Oct 06, 2015


Mycobacterium avium complex (MAC) infection usually presents in 1 of 3 forms:

  • Pulmonary MAC infection in immunocompetent hosts
  • Disseminated MAC (DMAC) infection in individuals with advanced AIDS
  • MAC lymphadenitis in children

Pulmonary MAC infection in immunocompetent hosts generally manifests as cough, sputum production, weight loss, fever, lethargy, and night sweats. The onset of symptoms is insidious. Symptoms may be present for weeks to months. Many patients have only a chronic cough with purulent sputum production. Hemoptysis is rare in MAC infection. Less commonly, MAC has been associated with hot-tub lung, a type of hypersensitivity pneumonitis-like lung disease due to exposure to MAC in hot tubs.

Patients with advanced AIDS (generally with CD4 counts < 50 cells/µL) who have DMAC infection commonly present with fever of unknown origin (FUO). Usual signs and symptoms are as follows:

  • Sweating
  • Weight loss
  • Fatigue
  • Diarrhea
  • Shortness of breath
  • Right upper quadrant abdominal pain

In addition, other reported MAC infection manifestations in patients with AIDS have included mastitis, pyomyositis, cutaneous abscess, brain abscess, and GI mycobacteriosis.

Immune reconstitution syndrome associated with MAC has been reported in patients with underlying MAC infection. These cases develop shortly after the patient initiates HAART.

MAC lymphadenitis is predominantly a disease of children aged 1-4 years, primarily involving unilateral cervical lymph nodes. Submandibular and submaxillary lymph nodes are the usual sites, but preauricular, postauricular, and submental nodes may also be affected. Rarely, infection of the axillary, epitrochlear, or inguinal lymph nodes may develop following direct cutaneous inoculation.

The lymph nodes usually enlarge insidiously but may enlarge more rapidly in younger children. The lymphadenitis generally resolves spontaneously, but the lymph nodes may also caseate and rupture through the skin, forming a sinus tract with chronic discharge.

Less commonly, MAC may produce any of the following:

  • Skin and soft-tissue infections
  • Osteomyelitis
  • Peritonitis (in patients with cirrhosis)
  • Bursitis
  • Septic arthritis
  • Tenosynovitis

Any history of the introduction of a foreign object (eg, needle, splinter) should be sought if cutaneous MAC infection is suspected.


Physical Examination

Physical findings in MAC infection depend on the form of infection and the patient. In immunocompetent patients with pulmonary MAC infection, lung crackles, rhonchi, or both can generally be heard on auscultation. Additionally, depending on the type of lung lesion and severity of infection, patients with pulmonary MAC infection may have tachypnea, dullness on chest percussion, or bronchial breath sounds.

DMAC infection in patients with AIDS can cause generalized wasting, skin pallor, tender hepatosplenomegaly, and lymphadenopathy.

Lymphadenitis in children can cause unilateral enlargement of submandibular, preauricular, parotid, and/or postauricular lymph nodes. Involved nodes are usually multiple and rubbery to firm and may appear to be fixed to deeper structures. They may become matted together as the disease progresses. The overlying skin may appear shiny, thin, and erythematous or violaceous. Sinus tracts may be present in advanced cases.

Patients with synovitis may present with pain and swelling of a joint or features of bursitis or tenosynovitis.

Contributor Information and Disclosures

Janak Koirala, MD, MPH, FACP, FIDSA Professor and Division Chair, Division of Infectious Diseases, Department of Internal Medicine, Southern Illinois University School of Medicine

Janak Koirala, MD, MPH, FACP, FIDSA is a member of the following medical societies: American Association for the Advancement of Science, American College of Physicians-American Society of Internal Medicine, American Society for Microbiology, International AIDS Society, International Society for Infectious Diseases, International Society of Travel Medicine, Infectious Diseases Society of America

Disclosure: Nothing to disclose.

Specialty Editor Board

Francisco Talavera, PharmD, PhD Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Received salary from Medscape for employment. for: Medscape.

Aaron Glatt, MD Chief Administrative Officer, Executive Vice President, Mercy Medical Center, Catholic Health Services of Long Island

Aaron Glatt, MD is a member of the following medical societies: American College of Chest Physicians, American Association for Physician Leadership, American College of Physicians, American College of Physicians-American Society of Internal Medicine, American Medical Association, American Society for Microbiology, American Thoracic Society, American Venereal Disease Association, Infectious Diseases Society of America, International AIDS Society, Society for Healthcare Epidemiology of America

Disclosure: Nothing to disclose.

Chief Editor

Michael Stuart Bronze, MD David Ross Boyd Professor and Chairman, Department of Medicine, Stewart G Wolf Endowed Chair in Internal Medicine, Department of Medicine, University of Oklahoma Health Science Center; Master of the American College of Physicians; Fellow, Infectious Diseases Society of America

Michael Stuart Bronze, MD is a member of the following medical societies: Alpha Omega Alpha, American Medical Association, Oklahoma State Medical Association, Southern Society for Clinical Investigation, Association of Professors of Medicine, American College of Physicians, Infectious Diseases Society of America

Disclosure: Nothing to disclose.

Additional Contributors

Klaus-Dieter Lessnau, MD, FCCP Clinical Associate Professor of Medicine, New York University School of Medicine; Medical Director, Pulmonary Physiology Laboratory; Director of Research in Pulmonary Medicine, Department of Medicine, Section of Pulmonary Medicine, Lenox Hill Hospital

Klaus-Dieter Lessnau, MD, FCCP is a member of the following medical societies: American College of Chest Physicians, American College of Physicians, American Medical Association, American Thoracic Society, Society of Critical Care Medicine

Disclosure: Nothing to disclose.


The authors and editors of Medscape Reference gratefully acknowledge the contributions of previous author William B Harley, MD,to the development and writing of the source article.

  1. Nishiuchi Y, Maekura R, Kitada S, et al. The recovery of Mycobacterium avium-intracellulare complex (MAC) from the residential bathrooms of patients with pulmonary MAC. Clin Infect Dis. 2007 Aug 1. 45(3):347-51. [Medline].

  2. Dhillon SS, Watanakunakorn C. Lady Windermere syndrome: middle lobe bronchiectasis and Mycobacterium avium complex infection due to voluntary cough suppression. Clin Infect Dis. 2000 Mar. 30(3):572-5. [Medline].

  3. Hartman TE, Jensen E, Tazelaar HD, et al. CT findings of granulomatous pneumonitis secondary to Mycobacterium avium-intracellulare inhalation: "hot tub lung". AJR Am J Roentgenol. 2007 Apr. 188(4):1050-3. [Medline].

  4. Sood A, Sreedhar R, Kulkarni P, Nawoor AR. Hypersensitivity pneumonitis-like granulomatous lung disease with nontuberculous mycobacteria from exposure to hot water aerosols. Environ Health Perspect. 2007 Feb. 115(2):262-6. [Medline].

  5. Feller M, Huwiler K, Stephan R, et al. Mycobacterium avium subspecies paratuberculosis and Crohn's disease: a systematic review and meta-analysis. Lancet Infect Dis. 2007 Sep. 7(9):607-13. [Medline].

  6. Koirala J, Adamski A, Koch L, Stueber D, El-Azizi M, Khardori NM, et al. Interferon-gamma receptors in HIV-1 infection. AIDS Res Hum Retroviruses. 2008 Aug. 24(8):1097-102. [Medline].

  7. Koh WJ, Jeong BH, Jeon K, Lee NY, Lee KS, Woo SY, et al. Clinical Significance of the Differentiation between Mycobacterium avium and Mycobacterium intracellulare in M. avium Complex Lung Disease. Chest. 2012 May 24. [Medline].

  8. Thomson RM, Armstrong JG, Looke DF. Gastroesophageal reflux disease, acid suppression, and Mycobacterium avium complex pulmonary disease. Chest. 2007 Apr. 131(4):1166-72. [Medline].

  9. Mycobacterium avium Complex. Centers for Disease Control and Prevention. Available at Accessed: August 15, 2011.

  10. Cassidy PM, Hedberg K, Saulson A, McNelly E, Winthrop KL. Nontuberculous mycobacterial disease prevalence and risk factors: a changing epidemiology. Clin Infect Dis. 2009 Dec 15. 49(12):e124-9. [Medline].

  11. Maugein J, Dailloux M, Carbonnelle B, et al. Sentinel-site surveillance of Mycobacterium avium complex pulmonary disease. Eur Respir J. 2005 Dec. 26(6):1092-6. [Medline].

  12. Freeman J, Morris A, Blackmore T, et al. Incidence of nontuberculous mycobacterial disease in New Zealand, 2004. N Z Med J. 2007 Jun 15. 120(1256):U2580. [Medline].

  13. Han XY, Tarrand JJ, Infante R, et al. Clinical significance and epidemiologic analyses of Mycobacterium avium and Mycobacterium intracellulare among patients without AIDS. J Clin Microbiol. 2005 Sep. 43(9):4407-12. [Medline].

  14. Gordin FM, Sullam PM, Shafran SD, et al. A randomized, placebo-controlled study of rifabutin added to a regimen of clarithromycin and ethambutol for treatment of disseminated infection with Mycobacterium avium complex. Clin Infect Dis. 1999 May. 28(5):1080-5. [Medline].

  15. Hayashi M, Takayanagi N, Kanauchi T, Miyahara Y, Yanagisawa T, Sugita Y. Prognostic Factors of 634 HIV-Negative Patients with Mycobacterium avium Complex Lung Disease. Am J Respir Crit Care Med. 2012 Mar 1. 185(5):575-83. [Medline].

  16. Perrin C. A patient with acquired immunodeficiency syndrome (AIDS) and a cutaneous Mycobacterium avium intracellulare infection mimicking histoid leprosy. Am J Dermatopathol. 2007 Aug. 29(4):422. [Medline].

  17. Kitada S, Kobayashi K, Ichiyama S, et al. Serodiagnosis of Mycobacterium avium-complex pulmonary disease using an enzyme immunoassay kit. Am J Respir Crit Care Med. 2008 Apr 1. 177(7):793-7. [Medline].

  18. [Guideline] Griffith DE, Aksamit T, Brown-Elliott BA, et al. An official ATS/IDSA statement: diagnosis, treatment, and prevention of nontuberculous mycobacterial diseases. Am J Respir Crit Care Med. 2007 Feb 15. 175(4):367-416. [Medline]. [Full Text].

  19. Kasperbauer SH, Daley CL. Diagnosis and treatment of infections due to Mycobacterium avium complex. Semin Respir Crit Care Med. 2008 Oct. 29(5):569-76. [Medline].

  20. Davis KK, Kao PN, Jacobs SS, et al. Aerosolized amikacin for treatment of pulmonary Mycobacterium avium infections: an observational case series. BMC Pulm Med. 2007 Feb 23. 7:2. [Medline].

  21. Selby W, Pavli P, Crotty B, et al. Two-year combination antibiotic therapy with clarithromycin, rifabutin, and clofazimine for Crohn's disease. Gastroenterology. 2007 Jun. 132(7):2313-9. [Medline].

  22. Lam PK, Griffith DE, Aksamit TR, Ruoss SJ, Garay SM, Daley CL. Factors related to response to intermittent treatment of Mycobacterium avium complex lung disease. Am J Respir Crit Care Med. 2006 Jun 1. 173(11):1283-9. [Medline].

  23. Field SK, Cowie RL. Treatment of Mycobacterium avium-intracellulare complex lung disease with a macrolide, ethambutol, and clofazimine. Chest. 2003 Oct. 124(4):1482-6. [Medline].

  24. Jenkins PA, Campbell IA, Banks J, Gelder CM, Prescott RJ, Smith AP. Clarithromycin vs ciprofloxacin as adjuncts to rifampicin and ethambutol in treating opportunist mycobacterial lung diseases and an assessment of Mycobacterium vaccae immunotherapy. Thorax. 2008 Jul. 63(7):627-34. [Medline].

  25. [Guideline] Kaplan JE, Benson C, Holmes KH, Brooks JT, Pau A, Masur H. Guidelines for prevention and treatment of opportunistic infections in HIV-infected adults and adolescents: recommendations from CDC, the National Institutes of Health, and the HIV Medicine Association of the Infectious Diseases Society of America. MMWR Recomm Rep. 2009 Apr. 58:1-207. [Medline].

  26. Chaisson RE, Keiser P, Pierce M, Fessel WJ, Ruskin J, Lahart C, et al. Clarithromycin and ethambutol with or without clofazimine for the treatment of bacteremic Mycobacterium avium complex disease in patients with HIV infection. AIDS. 1997 Mar. 11(3):311-7. [Medline].

  27. de Silva TI, Cope A, Goepel J, et al. The use of adjuvant granulocyte-macrophage colony-stimulating factor in HIV-related disseminated atypical mycobacterial infection. J Infect. 2007 Apr. 54(4):e207-10. [Medline].

  28. Pierce M, Crampton S, Henry D, et al. A randomized trial of clarithromycin as prophylaxis against disseminated Mycobacterium avium complex infection in patients with advanced acquired immunodeficiency syndrome. N Engl J Med. 1996 Aug 8. 335(6):384-91. [Medline].

  29. Lindeboom J. Conservative wait-and-see therapy versus antibiotic treatment for nontuberculous mycobacterial cervicofacial lymphadenitis in children. Clin Infect Dis. Jan 15 2011. 52(2):180-4.

  30. Ichikawa K, van Ingen J, Koh WJ, Wagner D, Salfinger M, Inagaki T, et al. Genetic diversity of clinical Mycobacterium avium subsp. hominissuis and Mycobacterium intracellulare isolates causing pulmonary diseases recovered from different geographical regions. Infect Genet Evol. 2015 Oct 2. [Medline].

CT thorax of a 77-year-old woman who presented with chronic cough and sputum production, without a history of underlying pre-existing lung disease. Sputum culture grew Mycobacterium avium complex. The diagnosis was Lady Windermere syndrome.
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