Paronychia is a topic covered in the 5-Minute Clinical Consult.

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  • Superficial inflammation of the lateral and posterior folds of skin surrounding the fingernail or toenail
    • Acute: characterized by pain, erythema, and swelling; usually a bacterial infection appears after trauma. It can progress to abscess formation.
    • Chronic: characterized by swelling, tenderness, cuticle elevation, and nail dystrophy and separation lasting at least 6 weeks, or recurrent episodes of acute eponychial inflammation and drainage
    • May be considered work-related among bartenders, waitresses, nurses, and others who often wash their hands
  • System(s) affected: skin and nail bed
  • Synonym(s): eponychia, perionychia

Pediatric Considerations
Less common in pediatric age groups. Thumb/finger-sucking is a risk factor (anaerobes and Escherichia coli may be present).


  • Common in the United States
  • Predominant age: all ages
  • Predominant sex: female > male

Etiology and Pathophysiology

  • Acute: Staphylococcus aureus (1) most common and Streptococcus pyogenes (1); less frequently, Pseudomonas pyocyanea and Proteus vulgaris. In digits exposed to oral flora especially in pediatric age group, consider Eikenella corrodens, Fusobacterium, and Peptostreptococcus.
  • Chronic: eczematous reaction with secondary Candida albicans (~95%)
  • A paronychial infection commonly starts in the lateral nail fold.
  • Recurrent inflammation, persistent edema, and fibrosis of nail folds cause nail folds to round up and retract, exposing nail grooves to irritants, allergens, and pathogens.
  • Inflammation compromises ability of proximal nail fold to regenerate cuticle leading to decreased vascular supply. This can cause decrease efficacy of topical medications.
  • Early in the course, cellulitis alone may be present. An abscess can form if the infection does not resolve quickly.

Risk Factors

  • Acute: direct or indirect trauma to cuticle or nail fold, manicure/sculptured nails, nail biting, and thumb sucking and predisposing conditions such as diabetes mellitus (DM)
  • Chronic: frequent immersion of hands in water with excoriation of the lateral nail fold (e.g., chefs, bartenders, housekeepers, swimmers, dishwashers, nurses), DM, immunosuppression (reported association with antiretroviral therapy for HIV and with use of epidermal growth factor inhibitors)

General Prevention

  • Acute: Avoid trauma such as nail biting; prevent thumb sucking.
  • Chronic: Avoid allergens; keep fingers/hands dry; wear rubber gloves with a cotton liner. Prevent excoriation of the skin.
  • Keep nails short. Avoid manicures. Apply moisturizer after washing hands.
  • Good glycemic control in diabetic patients

Commonly Associated Conditions

  • DM
  • Eczema or atopic dermatitis
  • Certain medications: antiretroviral therapy (2) (especially protease inhibitors, indinavir, and lamivudine, in which toes more commonly involved) (2)
  • Immunosuppression (3)

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