Dermatologic Aspects of Actinomycosis Treatment & Management

Updated: May 07, 2018
  • Author: Talib Najjar, DMD, MDS, PhD; Chief Editor: Dirk M Elston, MD  more...
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Medical Care

The presence of associated bacteria in actinomycosis appears to be fundamental to the development of clinical infection (see Lab Studies). Therefore, antibiotic coverage should be aimed at all associated organisms in patients with actinomycosis. An aerobic environment is an unfavorable condition for the growth of Actinomyces species and thus halts the infection. [21, 23, 24, 25, 26, 27]

With the combination of administering penicillin therapy and creating an aerobic environment with surgery, cure has become the rule rather than the exception.

The treatment of choice for actinomycosis includes large doses of antibiotics and prolonged therapy coupled with drainage of the abscesses or radical excision of the sinus tracts. High penicillin concentrations are necessary to penetrate areas of fibrosis and suppuration and possibly the granules themselves. Occasionally, extensive actinomycosis may respond to intravenous penicillin alone, rendering surgery unnecessary.

If the actinomycosis is recognized early, cervicofacial infection has an excellent prognosis with the use of antibiotics alone. In the treatment of actinomycosis, tetracyclines are as effective as penicillin. Intravenous penicillin G (10-20 million U/d for 2-6 wk) followed by oral penicillin (2-4 g/d for an additional 3-12 mo) is the typical therapy for the most deep-seated infections. [28]

Actinomyces organisms are also susceptible to chloramphenicol, erythromycin, tetracyclines, and clindamycin but not to metronidazole or aminoglycosides.

When tuberculosis is suspected, the effects of rifampin therapy can mask the signs of undiagnosed pulmonary actinomycosis.

Because the bacterial species in actinomycosis do not vary in terms of their susceptibility to first-line drugs (eg, penicillin, tetracyclines, erythromycin, first-generation parenteral cephalosporins, clindamycin), infection with strains other than A israelii should also respond to adequate courses of treatment with penicillin G or any of its alternatives. Serum concentrations of sulfonamides (4-8 mg/dL) inhibit some strains of A israelii; therefore, proven cases of actinomycosis (that are not mistaken instances of nocardiosis) may occasionally respond to sulfonamides. Oral cephalosporins and semisynthetic penicillins (eg, oxacillin, dicloxacillin) are less active in vitro and are best avoided. [29]

The acquired resistance of Actinomyces species to antimicrobials, particularly to penicillin G, has not been confirmed in vivo. When the response to penicillin is poor, consider an undrained abscess or an associated infection with a resistant bacterium. European investigators favor the use of ampicillin for initial therapy because associated bacteria are less susceptible to penicillin G in vitro, and they use metronidazole or clindamycin as a secondary agent when Bacteroides fragilis or Bacteroides thetaiotaomicron is present. Imipenem produces an impressive response in extensive, complicated, and relapsing abdominothoracic infections that fail to respond to several surgical procedures and trials of penicillin G. [30, 31]


Surgical Care

Surgical management in actinomycosis has consisted of various treatment modalities, including excision of sinus tracts, drainage of the abscess cavities, removal of the bulky infected masses, and irrigation and curettage of the osteomyelitic bony lesions. [32]

The abscesses of actinomycosis should be drained, or sinus tracts should be radically excised. With the combined use of penicillin and surgery, cure has become the rule rather than the exception.



An oral and maxillofacial surgeon should be consulted because the jaws are involved. Other specialists in pulmonology and gastroenterology may be consulted if actinomycosis involves the lungs or GI tract.