Actinomycosis: Causes, Symptoms, and Treatment
Medically reviewed by Achuta Uppu, MD, Internal Medicine. Last reviewed: October 23, 2026.
What kind of doctor treats Actinomycosis?
An infectious disease doctor treats actinomycosis, a chronic (long-term) bacterial infection. It most often affects the face and neck and forms abscesses (pockets of pus). Treatment is antibiotics for several months to a year. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What is actinomycosis?
Actinomycosis is a long-term (chronic) bacterial infection. It most often affects the face and neck. It can also occur in the chest, abdomen, or pelvis. The bacteria that usually cause it are called Actinomyces israelii. These germs normally live in the mouth, nose, and gut and do not cause disease. If they get into tissue through a break in the skin or lining, they form abscesses (pockets of pus). A common sign is a hard lump on the jaw, which is why it is called lumpy jaw. The infection is not contagious, so it does not spread to other people.
Symptoms
Symptoms start slowly, and it may be weeks or months before the problem is found. Signs can include:
- A hard, red to reddish-purple lump on the face or upper neck.
- Jaw or face pain.
- Draining sores in the skin, where pus leaks out through a small channel.
- Fever and weight loss.
A chest infection can cause chest pain when you take a deep breath, a cough with phlegm (mucus), shortness of breath, and, uncommonly, night sweats. In the belly or pelvis, the infection can cause stomach pain. Pain may be mild or absent.
Causes and who gets it
The infection starts when Actinomyces bacteria enter tissue after trauma, surgery, or another infection. Common triggers are a tooth abscess or oral surgery. Poor dental hygiene raises the risk of lung infections from these bacteria. In rare cases, the infection affects women who have had an intrauterine device (IUD), a small birth control device placed in the womb. The lung form is most common in people 30 to 60 years old, and it is more common in men. Heavy alcohol use, lung scarring, and COPD (long-term lung disease) also raise the risk of the lung form.
How doctors diagnose it
The doctor asks about your symptoms and examines you. To find the bacteria, the lab can culture (grow) a sample of tissue or fluid. Doctors may also look at drained fluid under a microscope. A CT scan (a detailed x-ray picture) of the affected area may also be done. For a chest infection, tests may include a chest x-ray, a chest CT scan, and a sputum culture (a test of mucus you cough up).
Treatment
Treatment uses antibiotics for several months to a year. This long course is needed to clear the infection. Surgical drainage or removal of the affected area may be needed. If the infection is related to an IUD, the device must be removed. With treatment, full recovery can be expected. In rare cases, the infection can lead to meningitis (an infection of the covering of the brain and spinal cord).
When to see a doctor
Contact your doctor if you have a hard lump on the jaw or neck, fever, draining sores, or unexplained weight loss. Starting treatment right away helps quicken recovery. See a doctor right away if a lump starts draining pus or if you have fever with weight loss. Call 911 if you have trouble breathing, cough up blood, or have a bad headache with a stiff neck, confusion, or a seizure.
How a direct primary care or concierge doctor fits in
A direct primary care doctor charges a flat monthly fee instead of billing insurance, while a concierge doctor usually charges more and often works alongside insurance. A direct primary care doctor can check the lump, start the first tests, and refer you to an infectious disease doctor. The doctor can also keep track of your health during the long antibiotic course.
Common questions
Is actinomycosis contagious?
No. Actinomycosis does not spread to other people. The bacteria that cause it normally live in the mouth and nose. They only cause infection after a break in the skin or lining.
How long does treatment take?
Treatment usually takes antibiotics for several months to a year. Some people also need surgery to drain or remove the affected area. With treatment, full recovery can be expected.
What causes actinomycosis?
It usually starts when Actinomyces bacteria enter tissue after trauma, surgery, or another infection. A tooth abscess or oral surgery are common triggers. Poor dental hygiene also raises the risk of lung infections from these bacteria.
Sources
- MedlinePlus - Actinomycosis
- NIH Genetic and Rare Diseases Information Center - Actinomycotic infection
- MedlinePlus - Pulmonary actinomycosis
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
