Causes

Actinomycosis is usually caused by an anaerobic bacteria called Actinomyces israelii, which is a common and normally not disease-causing (nonpathogenic) organism found in the nose and throat.

Because of the bacteria's normal location in the nose and throat, actinomycosis most commonly appears in the face and neck. However, the infection can sometimes occur in the chest (pulmonary actinomycosis), abdomen, pelvis, or other areas of the body. The infection is not contagious.

Symptoms occur when the bacteria enters the facial tissues after trauma, surgery, or infection. Common triggers include dental abscess or oral surgery. The infection has also been seen in certain women who have had an intrauterine device (IUD) to prevent pregnancy.

Once in the tissue, it forms an abscess, producing a hard, red to reddish-purple lump, often on the jaw, from which comes the condition's common name, "lumpy jaw."

Eventually, the abscess breaks through the skin surface to produce a draining sinus tract.

Symptoms

• Draining sores in the skin, especially on the chest wall from lung infection with Actinomyces
• Fever
• Minimal or no pain
• Swelling or a hard, red to reddish-purple lump on the face or upper neck
• Weight loss

See also: Neck lumps

Exams and Tests

• Culture of the tissue or fluid shows Actinomyces species.
• Examination of drained fluid under a microscope shows "sulfur granules" in the fluid. They are yellowish granules made of clumped organisms.
• Examination under a microscope shows the Actinomyces species of bacteria.

Treatment

Treatment of actinomycosis usually requires antibiotics for several months to a year. Surgical drainage or removal of the lesion may be needed. If the condition is related to an IUD, the device must be removed.

Outlook (Prognosis)

With treatment, you should recover fully.

Possible Complications

Meningitis can rarely develop from this infection.

When to Contact a Medical Professional

Call your health care provider if you develop any of the symptoms of this disorder. Beginning treatment promptly helps quicken the recovery.

Prevention

Good oral hygiene and regular dentist visits may help prevent some forms of actinomycosis.

Alternative Names

Lumpy jaw

References

Brook I. Actinomycosis. In: Goldman L, Ausiello D, eds.Cecil Medicine. 24th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 337.

Updated: 4/6/2012

Reviewed by: Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington, School of Medicine. Jatin M. Vyas, MD, PhD, Assistant Professor in Medicine, Harvard Medical School; Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.