Actinomycosis is an infection primarily caused by the bacterium Actinomyces israelii. Infection most often occurs in the face and neck region and is characterized by the presence of a slowly enlarging, hard, red lump.


Actinomycosis is a relatively rare infection occurring in one out of 300,000 (1/300,000) people per year.

It is characterized by the presence of a lump or mass that often forms, draining sinus tracts to the skin surface. Fifty percent of actinomycosis cases are of the head and neck region (also called "lumpy jaw" and "cervicofacial actinomycosis"), 15% are in the chest, 20% are in the abdomen, and the rest are in the pelvis, heart, and brain. Menare three timesmore likely to develop actinomycosis than women.

Causes and symptoms

Actinomycosis is usually caused by the bacterium Actinomyces israelii. This bacterium is normally present in the mouth but can cause disease if it enters tissues following an injury. Actinomyces israelii is an anaerobic bacterium which means it dislikes oxygen but grows very well in deep tissues where oxygen levels are low. Tooth extraction, tooth disease, root canal treatment, jaw surgery, or poor dental hygiene can allow Actinomyces israelii to cause an infection in the head and neck region.
The main symptom of cervicofacial actinomycosis is the presence of a hard lump on the face or neck. The lump may or may not be red. Fever occurs in some cases.


Cervicofacial actinomycosis can be diagnosed by a family doctor or dentist and the patient may be referred to an oral surgeon or infectious disease specialist. The diagnosis of actinomycosis is based upon several things. The presence of a red lump with draining sinuses on the head or neck is strongly suggestive of cervicofacial actinomycosis. A recent history of tooth extraction or signs of tooth decay or poor dental hygiene aid in the diagnosis. Microscopic examination of the fluid draining from the sinuses shows the characteristic "sulfur Granules" (small yellow colored material in the fluid) produced by Actinomyces israelii. A biopsy may be performed to remove a sample of the infected tissue. This procedure can be performed under local anesthesia in the doctor's office. Occasionally the bacteria can be cultured from the sinus tract fluid or from samples of the infected tissue.

Actinomycosis in the lungs, abdomen, pelvis, or brain can be very hard to diagnose since the symptoms often mimic those of other diseases. Actinomycosis of the lungs or abdomen can resemble tuberculosis or cancer. Diagnostic x-ray results, the presence of draining sinus tracts, and microscopic analysis and culturing of infected tissue assist in the diagnosis.


Actinomycosis is difficult to treat because of its dense tissue location. Surgery is often required to drain the lesion and/or to remove the site of infection. To kill the bacteria, standard therapy has included large doses of penicillin given through a vein daily for two to six weeks followed by six to twelve months of penicillin taken by mouth. Tetracycline, clindamycin, or erythromycin may be used instead of penicillin. The antibiotic therapy must be completed to ensure that the infection does not return. However, a report in 2004 on several cases of actinomycosis said that therapy depends on the individual case and that many patients today will be diagnosed in earlier stages of the disease. Sometimes, shorter courses of antibiotic treatment are effective, with close diagnostic x-ray monitoring. Hyperbaric oxygen (oxygen under high pressure) therapy in combination with the antibiotic therapy has been successful.

Prognosis and prevention

Complete recovery is achieved following treatment. If left untreated, the infection may cause localized bone destruction.

The best prevention is to maintain good dental hygiene.