Medscape is available in 5 Language Editions – Choose your Edition here.


Dermatologic Aspects of Actinomycosis Treatment & Management

  • Author: Talib Najjar, DMD, MDS, PhD; Chief Editor: Dirk M Elston, MD  more...
Updated: Jun 27, 2016

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.[19, 22, 23, 24, 25]

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.[26]

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.[27]

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.[28]


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.

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.

Contributor Information and Disclosures

Talib Najjar, DMD, MDS, PhD Professor of Oral and Maxillofacial Surgery and Pathology, Rutgers School of Dental Medicine

Talib Najjar, DMD, MDS, PhD is a member of the following medical societies: American Society for Clinical Pathology

Disclosure: Nothing to disclose.

Specialty Editor Board

Michael J Wells, MD, FAAD Associate Professor, Department of Dermatology, Texas Tech University Health Sciences Center, Paul L Foster School of Medicine

Michael J Wells, MD, FAAD is a member of the following medical societies: Alpha Omega Alpha, American Academy of Dermatology, American Medical Association, Texas Medical Association

Disclosure: Nothing to disclose.

Drore Eisen, MD, DDS Consulting Staff, Department of Dermatology, Dermatology Research Associates of Cincinnati

Drore Eisen, MD, DDS is a member of the following medical societies: American Academy of Dermatology, American Academy of Oral Medicine, American Dental Association

Disclosure: Nothing to disclose.

Chief Editor

Dirk M Elston, MD Professor and Chairman, Department of Dermatology and Dermatologic Surgery, Medical University of South Carolina College of Medicine

Dirk M Elston, MD is a member of the following medical societies: American Academy of Dermatology

Disclosure: Nothing to disclose.

Additional Contributors

Janet Fairley, MD Professor and Head, Department of Dermatology, University of Iowa, Roy J and Lucille A Carver College of Medicine

Janet Fairley, MD is a member of the following medical societies: American Academy of Dermatology, American Federation for Medical Research, Society for Investigative Dermatology

Disclosure: Nothing to disclose.


Many thanks for continuous help and advice from doctor Edward Jonson, MD, internationally known infectious diseases specialist and Dean, Trinity School of Medicine and Caribbean Studies, Saint Vincent.

  1. Nordqvist C. What is Actinomycosis? What causes Actinomycosis?. Medical News Today. Available at May 8, 2012; Accessed: June 14, 2016.

  2. Martín-Cabrejas BM, Gargantilla-Madera P, Pintor-Holguin E. Cervicofacial Actinomycosis. J Fam Med Dis Prevent. 2016. 2(1):[Full Text].

  3. Könönen E, Wade WG. Actinomyces and related organisms in human infections. Clin Microbiol Rev. 2015 Apr. 28 (2):419-42. [Medline].

  4. Schaal KP, Schofield GM. Classification and identification of clinically significant Actinomycetaceae. Ortiz-Ortiz L, Bojalil LF, Yakoleff V, eds. Biological, Biochemical, and Biomedical Aspects of Actinomycetes. Orlando, Fla: Academic Press; 1984. 505-20.

  5. Eastridge CE, Prather JR, Hughes FA Jr, Young JM, McCaughan JJ Jr. Actinomycosis: a 24 year experience. South Med J. 1972 Jul. 65(7):839-43. [Medline].

  6. Richtsmeier WJ, Johns ME. Actinomycosis of the head and neck. CRC Crit Rev Clin Lab Sci. 1979 Nov. 11(2):175-202. [Medline].

  7. Erikson D. Pathogenic anaerobic organisms of the Actinomyces group. Br Med Res Council Special Report Series. 1940. 240:1.

  8. Waksman SA, Henrici AT. The Nomenclature and Classification of the Actinomycetes. J Bacteriol. 1943 Oct. 46(4):337-41. [Medline].

  9. Georg LK. The agents of human actinomycosis. Balows A, Dehau RM, Dowell VR, eds. Anaerobic Bacteria: Role in Disease. Springfield, Ill: Charles C Thomas; 1974. 237-56.

  10. Brock DW, Georg LK, Brown JM, Hicklin MD. Actinomycosis caused by Arachnia propionica: report of 11 cases. Am J Clin Pathol. 1973 Jan. 59(1):66-77. [Medline].

  11. Behbehani MJ, Heeley JD, Jordan HV. Comparative histopathology of lesions produced by Actinomyces israelii, Actinomyces naeslundii, and Actinomyces viscosus in mice. Am J Pathol. 1983 Mar. 110(3):267-74. [Medline].

  12. Najjar TA, McKeon J, Smith L, Parson R. Septic arthritis of TMJ secondary to experimental osteosynthesis. J Dent Res. 1980. 59A:306.

  13. Weese WC, Smith IM. A study of 57 cases of actinomycosis over a 36-year period. A diagnostic 'failure' with good prognosis after treatment. Arch Intern Med. 1975 Dec. 135(12):1562-8. [Medline].

  14. Bennhoff DF. Actinomycosis: diagnostic and therapeutic considerations and a review of 32 cases. Laryngoscope. 1984 Sep. 94(9):1198-217. [Medline].

  15. Coleman RM, Georg LK, Rozzell AR. Actinomyces naeslundii as an agent of human actinomycosis. Appl Microbiol. 1969 Sep. 18(3):420-6. [Medline].

  16. Eng RH, Corrado ML, Cleri D, Cherubin C, Goldstein EJ. Infections caused by Actinomyces viscosus. Am J Clin Pathol. 1981 Jan. 75(1):113-6. [Medline].

  17. Pine L, Overman JR. Determination of the structure and composition of the "sulphur granules" of Actinomyces bovis. J Gen Microbiol. 1963 Aug. 32:209-23. [Medline].

  18. Brown JR. Human actinomycosis. A study of 181 subjects. Hum Pathol. 1973 Sep. 4(3):319-30. [Medline].

  19. Lewis RP, Sutter VL, Finegold SM. Bone infections involving anaerobic bacteria. Medicine (Baltimore). 1978 Jul. 57(4):279-305. [Medline].

  20. Peloux Y, Raoult D, Chardon H, Escarguel JP. Actinomyces odontolyticus infections: review of six patients. J Infect. 1985 Sep. 11(2):125-9. [Medline].

  21. Metgud SC. Primary cutaneous actinomycosis: a rare soft tissue infection. Indian J Med Microbiol. 2008 Apr-Jun. 26(2):184-6. [Medline].

  22. Schaal KP, Beaman BL. Clinical significance of actinomycetes. Goodfellow M, Mordarski M, Williams S, eds. The Biology of the Actinomycetes. New York: Academic Press; 1983. 389-424.

  23. Hennrikus EF, Pederson L. Disseminated actinomycosis. West J Med. 1987 Aug. 147(2):201-4. [Medline].

  24. Lerner PI. Susceptibility of pathogenic actinomycetes to antimicrobial compounds. Antimicrob Agents Chemother. 1974 Mar. 5(3):302-9. [Medline].

  25. Deshpande RB, Rao AA. Cervicofacial actinomycosis with upper cervical vertebral involvement and fatal meningitis (a case report). J Postgrad Med. 1985 Oct. 31(4):223-5. [Medline].

  26. Holmberg K, Nord CE, Dornbusch K. Antimicrobial in vitro susceptibility of actinomyces israelii and arachnia propionica. Scand J Infect Dis. 1977. 9(1):40-5. [Medline].

  27. Boand A, Novak M. Sensitivity changes of Actinomyces bovis to penicillin and streptomycin. J Bacteriol. 1949 May. 57(5):501-8. [Medline].

  28. Edelmann M, Cullmann W, Nowak KH, Kozuschek W. Treatment of abdominothoracic actinomycosis with imipenem. Eur J Clin Microbiol. 1987 Apr. 6(2):194-5. [Medline].

Photomicrograph of gram-positive organisms in actinomycosis, which may be confused with those causing a mycotic infection (hematoxylin and eosin, original magnification X40).
Photomicrograph of a characteristic sulfur granule of actinomycosis (hematoxylin and eosin, original magnification X10).
Diagram of potential oral anaerobic infection.
Image shows an oral fistula caused by actinomycosis.
Periapical radiograph shows infection in the premolar tooth.
All material on this website is protected by copyright, Copyright © 1994-2016 by WebMD LLC. This website also contains material copyrighted by 3rd parties.