Actinomycosis is a long-term (chronic) bacterial infection that commonly affects the face and neck.

Lumpy jaw

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.

• 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

• 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 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.

With treatment, you should recover fully.

Meningitis can rarely develop from this infection.

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

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

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