paronychia

PARONYCHIA - Medical Keyword Reference

Paronychia is inflammation or infection of the skin around the fingernail or toenail, affecting one or more of the three nail folds (proximal and lateral).¹²³

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Short and Long Definitions

Short definition Paronychia is infection or inflammation of the nail fold, presenting as painful, red, swollen tissue around the base or sides of the nail.²⁴³

Long definition Paronychia is a soft tissue infection affecting the proximal and lateral nail folds (perionychium) of the fingers or toes, occurring when the protective barrier between the nail and surrounding skin (cuticle/eponychium) is disrupted through trauma, allowing bacterial, fungal, or viral organisms to colonize the area; classified as acute (<6 weeks, painful purulent bacterial infection typically from Staphylococcus aureus or Streptococcus) or chronic (>6 weeks, multifactorial inflammation from irritants, moisture exposure, or Candida species); presents with erythema, edema, tenderness, and often purulent drainage; complications include abscess formation, nail deformity, osteomyelitis, and rarely systemic spread; treatment ranges from conservative warm soaks and topical antibiotics to incision and drainage for acute cases, with chronic cases requiring avoidance of irritants and antifungal therapy.³⁵⁶¹²

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Etymology

• Par-/Para-: Greek para- (παρά) = “beside, near, alongside.”
• Onych-: Greek ónyx, ónychos (ὄνυξ, ὄνυχος) = “nail, claw.”
• -ia: Greek suffix = “condition, disease.”
• Literal: “Condition beside the nail” or “inflammation around the nail.”

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Classification

Type	Duration/Characteristics	Primary Etiology
Acute paronychia	<6 weeks; sudden onset, painful, purulent.13	Bacterial (Staphylococcus aureus, Streptococcus pyogenes, Pseudomonas).
Chronic paronychia	>6 weeks; gradual onset, recurrent inflammation.13	Irritant/allergic dermatitis, moisture exposure; secondary Candida albicans colonization.
Herpetic whitlow	Viral subtype; vesicular lesions.3	Herpes simplex virus (HSV-1/2).
Drug-induced paronychia	Multiple nails affected.37	Chemotherapy (EGFR inhibitors, retinoids), immunosuppressants.

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Coding Context

ICD-10-CM:

Code	Description
L03.011	Cellulitis of right finger.
L03.012	Cellulitis of left finger.
L03.031	Cellulitis of right toe.
L03.032	Cellulitis of left toe.
L60.0	Ingrowing nail (can cause paronychia).
L03.90	Cellulitis, unspecified.
B37.2	Candidiasis of skin and nail (chronic fungal paronychia).

CPT Codes (Procedures):

Code	Description
10060	Incision and drainage of abscess; simple or single.
10061	Incision and drainage of abscess; complicated or multiple.
11740	Evacuation of subungual hematoma.
11750	Excision of nail and nail matrix, partial or complete (for chronic/refractory cases).

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Etiology and Risk Factors

Causative organisms:⁵²³

• Acute bacterial: Staphylococcus aureus (most common), Streptococcus pyogenes, Pseudomonas aeruginosa, mixed oral flora (nail-biting).
• Chronic fungal: Candida albicans (most common), dermatophytes.
• Viral: Herpes simplex virus (herpetic whitlow).

Predisposing factors:⁶¹²³

• Trauma: Nail-biting, finger-sucking (children), aggressive manicuring, artificial nails, hangnails.
• Occupational: Frequent water exposure (dishwashers, bartenders, housekeepers, food handlers, healthcare workers).
• Medical conditions: Diabetes, immunosuppression (HIV, malignancy), peripheral vascular disease.
• Medications: Chemotherapy agents (EGFR inhibitors like erlotinib, cetuximab), retinoids, antiretrovirals.
• Structural: Ingrown toenails, onycholysis, psoriasis.

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Clinical Features

Acute paronychia symptoms:⁴⁸³⁶

• Sudden onset (hours to days).
• Severe pain, throbbing.
• Erythema (redness) of nail fold.
• Edema (swelling).
• Warmth, tenderness to palpation.
• Purulent drainage or abscess formation.
• Usually single digit affected.
• May have fluctuant mass under cuticle.

Chronic paronychia symptoms:⁸¹³

• Gradual onset (weeks to months).
• Mild to moderate tenderness.
• Persistent erythema and swelling.
• Absent or retracted cuticle (loss of eponychium).
• Nail changes: thickening, ridging, discoloration (green from Pseudomonas, yellow-brown).
• Nail separation from nail bed (onycholysis).
• Acute exacerbations with pus.
• Multiple nails may be involved.

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Related Terms

• Eponychium: Cuticle; protective skin barrier at nail base.³
• Perionychium: Tissue surrounding the nail (3 nail folds).⁶
• Onycholysis: Nail separation from nail bed.
• Onychia: Infection of the nail plate itself.
• Felon: Deep infection of fingertip pulp space.
• Herpetic whitlow: HSV infection of finger (vesicular, not purulent).
• Subungual abscess: Pus collection under nail plate.
• Beau’s lines: Transverse nail ridges from acute illness/trauma.

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Diagnostic Workup

Clinical diagnosis:³⁶

• Primarily based on history and physical examination.
• History of trauma, nail manipulation, water exposure, occupation.

Laboratory/imaging (if needed):

• Gram stain and culture: Identify organism, guide antibiotic therapy (especially chronic/refractory cases).
• KOH preparation: Detect fungal elements (Candida, dermatophytes).
• Viral culture/PCR: If herpetic whitlow suspected.
• X-ray: Rule out osteomyelitis, foreign body (chronic cases, diabetics).

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Management and Treatment

Acute paronychia (bacterial):¹²⁴³

Stage	Treatment
Early (cellulitis only)	Warm water soaks or Burow solution (aluminum acetate) 10-15 min 3-4x/day; topical antibiotics (mupirocin, bacitracin).
Abscess present	Incision and drainage (I &D, CPT 10060): Lift nail fold or remove portion of nail to drain pus; pack with gauze.
Oral antibiotics	Dicloxacillin, cephalexin, clindamycin (MRSA coverage), or amoxicillin-clavulanate (covers S. aureus, Streptococcus, anaerobes).
Severe/systemic	IV antibiotics, hospitalization (diabetics, immunocompromised).

Chronic paronychia (irritant/fungal):⁵¹³

• Avoid irritants: Minimize water exposure, wear protective gloves (with cotton liners).
• Keep dry: Thoroughly dry hands after washing.
• Topical corticosteroids: Moderate-potency (triamcinolone 0.1%) for inflammation.
• Topical antifungals: Clotrimazole, ketoconazole, ciclopirox (if Candida suspected).
• Systemic antifungals: Fluconazole, itraconazole (refractory cases).
• Tacrolimus ointment: Alternative anti-inflammatory agent.
• Surgical excision: Marsupialize nail fold, partial nail removal (refractory cases, CPT 11750).

Herpetic whitlow:

• Conservative: Self-limited; oral acyclovir/valacyclovir if severe or immunocompromised.
• Avoid I &D: Can worsen viral spread.

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Complications

• Abscess formation: Requires surgical drainage.²³
• Nail dystrophy: Permanent nail deformity, thickening, ridging.
• Onycholysis: Nail separation.
• Osteomyelitis: Bone infection (rare, especially in diabetics/immunocompromised).
• Felon: Extension into fingertip pulp.
• Systemic infection: Sepsis, lymphangitis (rare).
• Recurrence: Common in chronic paronychia without irritant avoidance.

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Prevention

• Avoid nail-biting, finger-sucking, picking at cuticles.
• Gentle nail care; avoid aggressive manicuring or pushing back cuticles.
• Keep hands dry; use protective gloves for wet work.
• Moisturize hands and cuticles.
• Trim nails properly (straight across, not too short).
• Treat underlying conditions (diabetes control, fungal nail infections).

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Prognosis

• Acute paronychia: Excellent with appropriate treatment; usually resolves within 7-10 days.⁷
• Chronic paronychia: May persist for months to years without irritant avoidance; recurrence common.
• Untreated: Risk of abscess, nail loss, osteomyelitis.

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One-Sentence Summary

Paronychia (L03.011/L03.012, Greek para-onych-ia “beside the nail”), acute bacterial (S. aureus purulent <6 weeks) or chronic irritant/fungal (Candida >6 weeks) nail fold inflammation from trauma/moisture, presents with painful erythematous swelling, treated via warm soaks/I &D (10060) for acute cases or irritant avoidance/topical antifungals for chronic, with excellent acute prognosis but recurrent chronic course.¹²⁶³

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Document created: February 13, 2026 Medical coding professional reference ⁹¹⁰

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Footnotes

1. https://www.aafp.org/pubs/afp/issues/2017/0701/p44.html ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹

2. https://my.clevelandclinic.org/health/diseases/15327-nail-infection-paronychia ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸

3. https://www.ncbi.nlm.nih.gov/books/NBK544307/ ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹² ↩¹³ ↩¹⁴ ↩¹⁵ ↩¹⁶ ↩¹⁷

4. https://medlineplus.gov/ency/article/001444.htm ↩ ↩² ↩³

5. https://dermnetnz.org/topics/paronychia ↩ ↩² ↩³

6. https://www.dermatologyadvisor.com/ddi/paronychia/ ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶

7. https://www.cancer.gov/publications/dictionaries/cancer-terms/def/acute-paronychia ↩ ↩²

8. https://familydoctor.org/condition/paronychia/ ↩ ↩²

9. https://kidshealth.org/HumanaOhio/en/parents/paronychia.html ↩

10. https://quality.healthfinder.fl.gov/health-encyclopedia/HIE/1/001444 ↩