Dermatologic Aspects of Actinomycosis Clinical Presentation

Updated: May 07, 2018
  • Author: Talib Najjar, DMD, MDS, PhD; Chief Editor: Dirk M Elston, MD  more...
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Constitutional symptoms of actinomycosis may include nonspecific complaints such as weight loss, coughing, chest pain, and fever. When actinomycosis involves the jawbones, it is usually associated with localized pain, swelling, and draining fistulas. Actinomycosis may mimic other bacterial osteomyelitis.


Physical Examination

Consider actinomycosis infection in the differential diagnosis of any acute, subacute, or chronic cutaneous or soft tissue swelling of the face, head, or neck.


The cervicofacial form of actinomycetes infection is the most common presentation of actinomycosis, occurring in 55% of patients.

GI ingestion of the organism leads to the abdominopelvic form, which affects approximately 20% of patients.

Tracheobronchial aspiration of the organism from the oral cavity leads to the pulmonothoracic presentation, [19] which occurs in 15% of patients. Thoracic infection may involve the lungs, pleurae, mediastinum, or chest wall. The classic, chronic, chest wall sinus that discharges granules is uncommon today because antibiotics tend to limit infection to the lung. [14]

Other manifestations of actinomycosis include a pelvic form of actinomycosis that is associated with the use of intrauterine contraceptive devices. [18]


Acute or chronic signs of systemic infection may be absent. The patient's temperature may be in the reference range.

Hemoptysis is unusual in actinomycosis, but it can occur with a lung abscess.

Actinomycosis may present as a simple phlegmon; a draining sinus; or an abscess in the cheek, in the angle of the jaw, or in the submandibular region (see the image below).

Diagram of potential oral anaerobic infection. Diagram of potential oral anaerobic infection.

The most common feature of actinomycosis infection is the presence of acute pyogenic infection in the submandibular or paramandibular area; in the angle of the mandible, maxilla, and palate; in the parotid region; or in the neck.

Primary infection in the skin of the face may spread to adjacent structures such as the scalp, orbit, ears, and other areas.

Oral infection may spread to the tongue, hypopharynx, larynx, trachea, salivary glands, and paranasal sinuses. [20]

Unlike other bacterial infections, actinomycosis spreads without regard for facial tissue planes and without adenopathy. Actinomycosis may mimic chronic but persistent osteomyelitis.

Actinomycosis infection in the jaw begins as a chronic tissue induration with trismus; ultimately, a draining cutaneous or oral fistula develops (see the image below). The fistula progresses to an acute suppurative infection with abscess formation beneath the skin and trismus, and the edema of the surrounding tissues is out of proportion to the degree of inflammation. [11]

Image shows an oral fistula caused by actinomycosi Image shows an oral fistula caused by actinomycosis.

Infection inside the oral cavity can present as an acute abscess, a subacute inflammatory nodule, an infiltrating mass, or a pseudotumor. It may not respond to initial antibiotic and conservative surgical manipulation.

Persistent infection in the periapical area of the tooth, especially in the premolar and molar region, may harbor actinomycetes, which can lead to the development of an oral or skin sinus fistula (see the image below).

Periapical radiograph shows infection in the premo Periapical radiograph shows infection in the premolar tooth.

Primary long bone infection is rare. Osseous involvement in actinomycosis is derived from adjacent soft tissue infection, provoking a painful periostitis that results in new bone formation at the site of infection, which can be seen at radiography (see Imaging Studies). The mandible is 4 times more commonly involved than the maxilla. [21]



Long-standing bony involvement caused by actinomycosis may lead to osteomyelitis and bone necrosis.