Commonality is rare
Actinomycosis is a chronic, non-contagious infection caused predominantly by Actinomyces israelii; a bacteria usually residing on the surface of teeth, gums, tonsils and the membranes of the intestines and vagina. Under normal circumstances, the bacteria do not cause illness.
Actinomycosis often occurs following surgery or trauma. It is most commonly diagnosed in men, although the increased usage of intra-uterine devices has seen a rise in the incidence of the disease in women.
Infection occurs when the surface of tissues inhabited by the bacteria are broken. This introduces the bacteria to deeper tissues which, unlike the surface, are susceptible to infection.
Once infected, the tissue becomes severely inflamed. The infection spreads to neighbouring tissues and organs, unhindered by tissue borders. Eventually, the characteristic abscesses and fistulae are formed.
This is a slow process, and diagnosis may follow the incidence of disease by months or years.
Symptoms and diagnosis
The exact symptoms of actinomycosis vary, depending on the region affected. Symptoms common to actinomycosis in all areas, however, include:
· Inflammation of the affected region;
· Scarring and subsequent damage to the tissue;
· Painful, pus-filled abscesses on the skin’s surface; and
· “Tunnels” (fistula) in the skin from which pus is discharged.
A sample of tissue or pus will show Actinomyces bacteria under examination with a microscope. Characteristic yellow granules, similar in appearance to crystalline sulfur, will also be visible in the discharged pus.
Treatment usually comprises high doses of antibiotics over several months. The abscesses are treated by draining the pus with a needle, and radiographic imaging can be used to monitor their gradual resolution. Surgery is required for the removal of fistulae, and abscesses located in or near to critical areas, such as the spine.
In most cases, patients are able to recover fully from actinomycosis.