Actinomycosis of the face
While common in cattle (especially young weaned bulls and heifers), actinomycosis is rare in humans. It’s an opportunistic infection, becoming entrenched while the immune system is compromised by disease or malnutrition, and when it becomes established inside the body (most often the chest) is often misdiagnosed as a neoplasm (neoplasm = “new growth” - a tumor).
On the face, it causes a slow-growing, lumpy surface, that ignores tissue layers, and creates sinuses (holes) that spontaneously heal and recur as the disease progresses.
While once thought to be a mycosis, or fungal infection (hence its name), actinomycosis is now known to be caused by anaerobic, gram-positive bacteria. As it’s still a very uncommon condition in humans, actinomycosis has not developed much resistance to antibiotics, and is generally responsive to penicillin and amoxicillin. However, because the bacteria can become so entrenched in areas that do not receive high amounts of blood flow, the antibiotics must be continued for up to a year, if the disease has been present for a long time.
Diseases of the Skin. James H. Sequiera, 1919.