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Gram-Negative Folliculitis Workup

  • Author: Mordechai M Tarlow, MD; Chief Editor: William D James, MD  more...
 
Updated: Mar 27, 2014
 

Laboratory Studies

The diagnosis of gram-negative folliculitis can often be made based on the history and the physical examination findings alone. However, confirmation with Gram stain and culture is recommended.

In confirming the diagnosis with Gram stain and culture, use special care in culturing. Gram-negative organisms are sensitive to desiccation; samples must be taken quickly and cultured as soon as possible. The pustule that is sampled should also be fresh. A small pustule on an erythematous base is preferable for culturing purposes.

Culture pustules in any patient with acne who is in their late teens or older and has been on antibiotics and develops a pustular form of the disease.

Gram-negative organisms cannot be recovered from every pustule.

Selective medium-containing dyes, such as methylene blue, allow selective growth of gram-negative organisms while inhibiting growth of gram-positive organisms.

The organisms that produce colonies on eosin-methylene blue agar are classified as either lactose-fermenting gram-negative rods or Proteus species by their cultural characteristics and their ability to ferment lactose.

  • Lactose-fermenting, gram-negative rods produce small, dark, discreet, metallic colonies.
  • Proteus species produce rapidly spreading, translucent, and odorous colonies.

In patients with facial folliculitis that presents a diagnostic challenge, a potassium hydroxide mount (10-20% potassium hydroxide is used to stain a sample on a slide and look for possible fungal elements) and a skin biopsy specimen may be of value.

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Histologic Findings

In contrast to typical acne lesions, lesions of gram-negative folliculitis do not contain a comedonal core. A minimal amount of keratinous material is present in an intrafollicular sea of pus. Occasionally, segments of the follicular wall may be dissolved. Organisms are located in nests around clumps of keratinous material, around hairs, and in phagocytes. In contrast to the predominant gram-negative rod recovered on culture, Gram stain of the tissue section may show a mixed flora (ie, gram-positive rods and cocci, gram-negative rods, budding yeasts).

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Contributor Information and Disclosures
Author

Mordechai M Tarlow, MD Clinical Assistant Professor of Dermatology, University of Pennsylvania School of Medicine

Mordechai M Tarlow, MD is a member of the following medical societies: Alpha Omega Alpha, American Academy of Dermatology, American Society for MOHS Surgery, American College of Aesthetic and Cosmetic Physicians; American Society of Aesthetic/Cosmetic Physicians, American Medical Association, Sigma Xi

Disclosure: Nothing to disclose.

Coauthor(s)

Robert A Schwartz, MD, MPH Professor and Head of Dermatology, Professor of Pathology, Pediatrics, Medicine, and Preventive Medicine and Community Health, Rutgers New Jersey Medical School; Visiting Professor, Rutgers University School of Public Affairs and Administration

Robert A Schwartz, MD, MPH is a member of the following medical societies: Alpha Omega Alpha, New York Academy of Medicine, American Academy of Dermatology, American College of Physicians, Sigma Xi

Disclosure: Nothing to disclose.

Michael Wiederkehr, MD Consulting Staff, Livingston Dermatology Associates; Consulting Staff, Comprehensive Dermatology and Laser Center

Michael Wiederkehr, MD is a member of the following medical societies: Alpha Omega Alpha, American Medical Association

Disclosure: Nothing to disclose.

Sofia Piela, MD Head, Department of Dermatology, Rzeszow Regional Health Center, Poland

Disclosure: Nothing to disclose.

Specialty Editor Board

Francisco Talavera, PharmD, PhD Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Received salary from Medscape for employment. for: Medscape.

Rosalie Elenitsas, MD Herman Beerman Professor of Dermatology, University of Pennsylvania School of Medicine; Director, Penn Cutaneous Pathology Services, Department of Dermatology, University of Pennsylvania Health System

Rosalie Elenitsas, MD is a member of the following medical societies: American Academy of Dermatology, American Medical Association, American Society of Dermatopathology, Pennsylvania Academy of Dermatology

Disclosure: Received royalty from Lippincott Williams Wilkins for textbook editor.

Chief Editor

William D James, MD Paul R Gross Professor of Dermatology, Vice-Chairman, Residency Program Director, Department of Dermatology, University of Pennsylvania School of Medicine

William D James, MD is a member of the following medical societies: American Academy of Dermatology, Society for Investigative Dermatology

Disclosure: Nothing to disclose.

Additional Contributors

Andrea Leigh Zaenglein, MD Professor of Dermatology and Pediatrics, Department of Dermatology, Hershey Medical Center, Pennsylvania State University College of Medicine

Andrea Leigh Zaenglein, MD is a member of the following medical societies: American Academy of Dermatology, Society for Pediatric Dermatology

Disclosure: Received consulting fee from Galderma for consulting; Received consulting fee from Valeant for consulting; Received consulting fee from Promius for consulting; Received consulting fee from Anacor for consulting; Received grant/research funds from Stiefel for investigator; Received grant/research funds from Astellas for investigator; Received grant/research funds from Ranbaxy for other; Received consulting fee from Ranbaxy for consulting.

References
  1. Fulton JE Jr, McGinley K, Leyden J, Marples R. Gram-negative folliculitis in acne vulgaris. Arch Dermatol. 1968 Oct. 98(4):349-53. [Medline].

  2. Leyden JJ, Marples RR, Mills OH Jr, Kligman AM. Gram-negative folliculitis--a complication of antibiotic therapy in acne vulgaris. Br J Dermatol. 1973 Jun. 88(6):533-8. [Medline].

  3. Chastain MA. A cycle: recurrent gram-negative folliculitis with Citrobacter diversus (koseri) following eradication of recurrent staphylococcal pyoderma. Arch Dermatol. 2000 Jun. 136(6):803. [Medline].

  4. Mostafa WZ. Citrobacter freundii in gram-negative folliculitis. J Am Acad Dermatol. 1989 Mar. 20(3):504-5. [Medline].

  5. Mulholland A, Yong-Gee S. A possible new cause of spa bath folliculitis: Aeromonas hydrophila. Australas J Dermatol. 2008 Feb. 49(1):39-41. [Medline].

  6. Julia Manresa M, Vicente Villa A, Gene Giralt A, Gonzalez-Ensenat MA. Aeromonas hydrophila folliculitis associated with an inflatable swimming pool: mimicking Pseudomonas aeruginosa infection. Pediatr Dermatol. 2009 Sep-Oct. 26(5):601-3. [Medline].

  7. Mulholland A, Yong-Gee S. A possible new cause of spa bath folliculitis: Aeromonas hydrophila. Australas J Dermatol. 2008 Feb. 49(1):39-41. [Medline].

  8. Bachmeyer C, Landgraf N, Cordier F, Lemaitre P, Blum L. Acinetobacter baumanii folliculitis in a patient with AIDS. Clin Exp Dermatol. 2005 May. 30(3):256-8. [Medline].

  9. Palit A, Inamadar AC. Current concepts in the management of bacterial skin infections in children. Indian J Dermatol Venereol Leprol. 2010 Sep-Oct. 76(5):476-88. [Medline].

  10. Böni R, Nehrhoff B. Treatment of gram-negative folliculitis in patients with acne. Am J Clin Dermatol. 2003. 4(4):273-6. [Medline].

  11. James WD, Leyden JJ. Treatment of gram-negative folliculitis with isotretinoin: positive clinical and microbiologic response. J Am Acad Dermatol. 1985 Feb. 12(2 Pt 1):319-24. [Medline].

  12. Plewig G, Nikolowski J, Wolff HH. Action of isotretinoin in acne rosacea and gram-negative folliculitis. J Am Acad Dermatol. 1982 Apr. 6(4 Pt 2 Suppl):766-85. [Medline].

  13. Blankenship ML. Gram-negative folliculitis. Follow-up observations in 20 patients. Arch Dermatol. 1984 Oct. 120(10):1301-3. [Medline].

  14. Leyden JJ, McGinley KJ, Mills OH. Pseudomonas aeruginosa gram-negative folliculitis. Arch Dermatol. 1979 Oct. 115(10):1203-4. [Medline].

  15. Marples RR, Fulton JE, Leyden J, McGinley KJ. Effect of antibiotics on the nasal flora in acne patients. Arch Dermatol. 1969 Jun. 99(6):647-51. [Medline].

  16. Neubert U, Jansen T, Plewig G. Bacteriologic and immunologic aspects of gram-negative folliculitis: a study of 46 patients. Int J Dermatol. 1999 Apr. 38(4):270-4. [Medline].

  17. Noble WC. Gram-negative bacterial skin infections. Semin Dermatol. 1993 Dec. 12(4):336-41. [Medline].

  18. Simjee S, Sahm DF, Soltani K, Morello JA. Organisms associated with gram-negative folliculitis: in vitro growth in the presence of isotretinoin. Arch Dermatol Res. 1986. 278(4):314-6. [Medline].

  19. Tan HH. Antibacterial therapy for acne: a guide to selection and use of systemic agents. Am J Clin Dermatol. 2003. 4(5):307-14. [Medline].

  20. Tarlow MM, Piela Z, Schwartz RA. Gram-negative folliculitis - a diagnostic challenge. Dermatologia Kliniczna. 2002. 4:7-9.

 
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Pseudomonas folliculitis. Courtesy of Hon Pak, MD.
 
 
 
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