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  • Cynthia M. Johnson, MA
Publication Type:




Actinomycosis is a rare bacterial infection. It causes pus to collect in the body. It may start in the:

  • Jaw
  • Lungs
  • Abdomen
  • Uterus

Rarely, the infection can spread from one place in the body to another.

Abdominal Abscess.

Abdominal Abscesshttp://services.epnet.com/getimage.aspx?imageiid=75067506si1390.jpgsi1390.jpgNULLjpgsi1390.jpgNULL\\hgfiler01a\intellect\images\si1390.jpgNULL47NULL2008-12-10261400Copyright © Nucleus Medical Media, Inc.


Certain bacteria cause actinomycosis. They are normal in the mouth and sometimes in the bowels. They get into the body through breaks in the tissues. Tooth decay causes infections in the mouth and jaw. This is the most common type.

Risk Factors

This infection is more common in men. Actinomycosis may be more common after:

  • Problems with teeth and gums or dental work
  • Saliva, food, or drink getting into the lungs
  • Long-lasting lung disease
  • Bowel surgery
  • Intrauterine device (IUD), especially if it has been in for a long time

There is also a higher risk of infection in people with:

  • Diabetes
  • A weakened immune system
  • Poor nutrition


Symptoms depend on the where the infection starts. They may involve:

  • Swelling in the mouth, neck, or jaw
  • Pus with tiny, yellowish specks
  • Pus that drains through the skin
  • Fever
  • Weight loss
  • Cough
  • Swelling or a hard lump in the belly


The doctor will ask about symptoms and past health. A physical exam will be done. Tests will be done to look for signs of infection. This may include:

  • Testing of fluids, pus, or phlegm
  • A biopsy to look at body tissues


The infection is treated with antibiotics. They are often started through an IV. The antibiotics may then be taken as pills for many months.

Surgery may also be needed to remove dead or infected tissue.


Good dental care may lower the risk of infection in the jaw.





  • Actinomycosis. Merck Manual Professional Version website. Available at: https://www.merckmanuals.com/professional/infectious-diseases/anaerobic-bacteria/actinomycosis.
  • Cervicofacial actinomycosis. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/cervicofacial-actinomycosis.
  • Moturi K, Kaila V. Cervicofacial actinomycosis and its management. Ann Maxillofac Surg. 2018;8(2):361-364.


  • David L. Horn, MD, FACP
Last Updated:

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.