title: Acne inversa complicated by Actinomyces neuii.
abstract: BACKGROUND
  Acne inversa (AI) is a chronic and recurrent inflammatory skin disease. It occurs in intertriginous areas of the skin and causes pain, drainage, malodor and scar formation. While supposedly caused by an autoimmune reaction, bacterial superinfection is a secondary event in the disease process.
  
  
  METHODS
  A unique case of a 43-year-old male patient suffering from a recurring AI lesion in the left axilla was retrospectively analysed.
  
  
  RESULTS
  A swab revealed Actinomyces neuii as the only agent growing in the lesion. The patient was then treated with Amoxicillin/Clavulanic Acid 3 × 1 g until he was cleared for surgical excision. The intraoperative swab was negative for A. neuii. Antibiotics were prescribed for another 4 weeks and the patient has remained relapse free for more than 12 months now.
  
  
  CONCLUSIONS
  Primary cutaneous Actinomycosis is a rare entity and the combination of AI and Actinomycosis has never been reported before. Failure to detect superinfections of AI lesions with slow-growing pathogens like Actinomyces spp. might contribute to high recurrence rates after immunosuppressive therapy of AI. The present case underlines the potentially multifactorial pathogenesis of the disease and the importance of considering and treating potential infections before initiating immunosuppressive regimens for AI patients.
authors.affiliation: Division of Plastic and Reconstructive Surgery, Department of Surgery, Medical University of Vienna, Vienna, Austria.
authors.forename: Jakob
authors.initials: J
authors.lastname: Nedomansky
authors.affiliation: Division of Immunology, Department of Dermatology, Allergy and Infectious Diseases, Medical University of Vienna, Vienna, Austria.
authors.forename: Doris
authors.initials: D
authors.lastname: Weiss
authors.affiliation: Division of Clinical Microbiology, Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria.
authors.forename: Birgit
authors.initials: B
authors.lastname: Willinger
authors.affiliation: Division of Plastic and Reconstructive Surgery, Department of Surgery, Medical University of Vienna, Vienna, Austria.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Nickl
authors.affiliation: Division of Infectious Diseases, Department of Medicine 1, Medical University of Vienna, Vienna, Austria. christoph.steininger@meduniwien.ac.at.
authors.forename: Christoph
authors.initials: C
authors.lastname: Steininger
mesh_terms: D000190:Actinomyces / Q000145:classification / Q000302:isolation & purification*; D000196:Actinomycosis / Q000175:diagnosis* / Q000473:pathology*; D000328:Adult; D017497:Hidradenitis Suppurativa / Q000150:complications / Q000175:diagnosis* / Q000473:pathology*; D006801:Humans; D008297:Male; D012189:Retrospective Studies
keywords: Acne inversa; Actinomyces neuii; Actinomycosis; Hidradenitis suppurativa; Soft tissue infection