title: Cellulitis Secondary to Liquid Nitrogen Cryotherapy: Case Report and Literature Review.
abstract: BACKGROUND
  Liquid nitrogen cryotherapy is a commonly used technique to treat a wide variety of dermatologic conditions including actinic keratoses, non-melanoma skin cancers, verrucae, and seborrheic keratoses. The risks associated with liquid nitrogen cryotherapy are important to know and discuss with patients prior to treatment.
  
  
  OBJECTIVE
  We report a case of cellulitis secondary to liquid nitrogen cryotherapy for actinic keratosis. We sought to review the literature for an estimate of secondary infection rates following cryotherapy treatment.
  
  
  METHODS
  We searched Pubmed using the terms cryotherapy and infection or cellulitis. We then looked at articles classified as clinical trials where cryotherapy was used to treat skin conditions. We then selected clinical trials that listed cellulitis or infection as an adverse event.
  
  
  CONCLUSIONS
  There were no case reports, case series, or review articles detailing the risk of infection from liquid nitrogen cryotherapy. We found 8 articles classified as clinical trials on Pubmed that did list infection as an adverse event. The risk of infection from these studies varied from approximately 2% to 30%. There was a great degree of heterogeneity in treatment sites, length of treatment, and treatment targets. While it is difficult to determine the true incidence of infection from liquid nitrogen cryotherapy, clinicians should endeavor to inform patients of this potential risk.
authors.affiliation: 1 Queen's School of Medicine, Queen's University, Kingston, ON, Canada.
authors.forename: Christina M
authors.initials: CM
authors.lastname: Huang
authors.affiliation: 1 Queen's School of Medicine, Queen's University, Kingston, ON, Canada.
authors.forename: Emily Y
authors.initials: EY
authors.lastname: Lu
authors.affiliation: 2 Division of Dermatology, Department of Medicine, Queen's University, Kingston, ON, Canada.
authors.forename: Mark G
authors.initials: MG
authors.lastname: Kirchhof
mesh_terms: D000368:Aged; D001132:Arm / Q000473:pathology; D002481:Cellulitis / Q000209:etiology / Q000473:pathology; D017679:Cryotherapy / Q000009:adverse effects* / Q000379:methods; D004890:Erythema / Q000209:etiology; D005260:Female; D006801:Humans; D055623:Keratosis, Actinic / Q000628:therapy; D009584:Nitrogen / Q000009:adverse effects* / Q000627:therapeutic use
chemical_list: D009584:Nitrogen
keywords: actinic keratosis; cellulitis; cryospray; infection; liquid nitrogen cryotherapy