Paronychia

Paronychia

Introduction

Paronychia is an infection and inflammation of the tissues surrounding the nail plate (peri-ungual tissues), particularly the proximal or lateral nail folds. It is one of the most common nail disorders and occurs when the protective barrier between the nail plate and nail fold is disrupted, allowing microorganisms to enter.

There are two major forms:

• Acute paronychia – sudden onset (hours to days), usually caused by bacterial infection, most commonly Staphylococcus aureus.

• Chronic paronychia – persistent infection lasting more than 6 weeks, commonly associated with fungal infection (Candida albicans) with or without mixed bacterial infection.

Etiology

Acute paronychia

Usually occurs following minor trauma to the nail fold, including:

• Nail biting

• Aggressive manicuring

• Hangnails

• Artificial nails

• Finger sucking in children

• Occupational injury

Common causative organisms:

• Staphylococcus aureus (most common)

• Streptococcus species

• Gram-negative organisms (less common)

Chronic paronychia

Usually results from repeated moisture exposure leading to destruction of the cuticle.

Common risk groups:

• Housewives

• Healthcare workers

• Food handlers

• Bartenders

• Fishermen

• People with diabetes mellitus

Common causative organisms:

• Candida albicans

• Mixed bacterial flora

Pathophysiology

The cuticle normally forms a protective seal between the nail plate and nail fold.

When this barrier is disrupted:

• Moisture enters the nail fold

• The cuticle separates from the nail plate

• Microorganisms colonize the nail groove

• Persistent inflammation develops

Acute disease commonly results in pus formation, whereas chronic disease may lead to inflammatory fibrosis and nail dystrophy.

Clinical presentation

Acute paronychia

Early features:

• Painful nail

• Redness around the nail fold

• Swelling

• Warmth

• Tenderness

Advanced disease:

• Fluctuant abscess

• Pus discharge

• Severe throbbing pain

• Fever (uncommon)

Chronic paronychia

• Swollen nail folds

• Loss of cuticle

• Mild or intermittent redness

• Minimal pain

• Nail ridging

• Thickened dystrophic nail

• Nail discoloration

• Recurrent exacerbations

Diagnostic criteria

Diagnosis is primarily clinical.

Acute paronychia:

• Sudden painful swelling around the nail

• Erythema

• Tenderness

• Possible pus collection

Chronic paronychia:

• Symptoms lasting more than 6 weeks

• Absent or damaged cuticle

• Nail dystrophy

• Mild persistent inflammation

Differential diagnosis

• Herpetic whitlow

• Felon (deep pulp infection)

• Ingrown toenail

• Onychomycosis

• Nail psoriasis

• Contact dermatitis

Investigations

Routine investigations are not usually required.

Consider in recurrent or complicated cases:

• Pus culture and sensitivity

• KOH microscopy for fungal infection

• Fungal culture

• Blood glucose testing to screen for diabetes mellitus

Treatment

Non-pharmacological treatment

Acute paronychia

• Warm saline soaks 3–4 times daily

• Elevate the affected digit

• Avoid squeezing the lesion

• Stop nail biting

• Avoid further trauma

Chronic paronychia

• Keep hands dry

• Avoid prolonged exposure to water

• Wear protective gloves during wet work

• Avoid irritants and detergents

• Apply emollients regularly

• Restore cuticle protection

Pharmacological treatment

Acute paronychia

Early infection without abscess:

• Amoxicillin with clavulanic acid (PO) 625 mg every 8 hours for 14 days

AND

• Mupirocin cream (topical) every 12 hours for 14 days

OR

• Clindamycin (PO) 300 mg every 12 hours for 14 days

Acute paronychia with abscess

Incision and drainage should be performed. Antibiotics alone are usually insufficient when pus is present.

Chronic paronychia (commonly due to fungal infection)

• Clotrimazole cream 1% (topical), apply every 12 hours for 14 days

AND

• Fluconazole (PO) 200 mg once daily for 14 days

OR

• Itraconazole (PO) 200 mg once daily for 14 days

Surgical treatment

Indications include:

• Fluctuant abscess

• Severe throbbing pain

• Failure of medical treatment

• Significant nail fold tension

Procedure:

• Incision and drainage of the abscess

• Irrigation of the cavity

• Appropriate wound dressing

Complications

• Nail dystrophy

• Permanent nail deformity

• Nail plate separation

• Cellulitis

• Felon

• Osteomyelitis (rare)

• Recurrent infection

Prevention

• Avoid nail biting

• Use proper manicure techniques

• Avoid cutting the cuticles

• Keep hands dry

• Wear protective gloves during prolonged wet work

• Control diabetes mellitus

• Treat fungal nail infections early

• Avoid prolonged use of artificial nails

Prognosis

• Acute paronychia generally has an excellent prognosis with early treatment and drainage when required.

• Chronic paronychia may take weeks to months to resolve and recurrence is common if predisposing factors persist.