Orthopaedic Surgery - Paronychia (Nail Infection)

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Basics

Paronychia is an infection or inflammatory process involving the lateral nail fold, typically along the radial or ulnar margin of a fingernail.

It may occur acutely after disruption of the nail fold or chronically after repeated exposure to moisture and irritants.

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Prevention

Preventive measures include:

Keeping nails clean and appropriately trimmed

Avoiding nail biting

Avoiding aggressive cuticle manipulation

Using gloves during wet work or exposure to irritants

Care should be taken during manicures to avoid injury to the nail fold.

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Epidemiology

Paronychia can occur at any age.

Older studies suggest that it is more common in:

Women

with an approximate female-to-male ratio of:

3:1.

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Risk Factors

Important risk factors include:

Nail biting

Hangnails

Manicures

Frequent water exposure

Diabetes mellitus

Chronic corticosteroid use

Chemotherapy

Other immunosuppressed states

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Etiology

Acute paronychia usually develops after disruption of the protective barrier between the nail plate and surrounding skin.

Common precipitating events include:

Hangnail formation

Biting the nail edge

Picking at the cuticle

Manicure instrumentation

The most common bacterial pathogen is:

Staphylococcus aureus.

Other organisms may be involved depending on the clinical setting.

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Associated Conditions

Several related infections may occur around the nail and fingertip.

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Eponychia

Eponychia involves the:

Proximal nail fold and periungual tissues.

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Felon

A felon is an infection of the:

Pulp space of the fingertip.

Because the pulp contains multiple fibrous septae, an abscess can generate substantial pressure and pain.

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Subungual Abscess

A subungual abscess develops:

Beneath the nail plate.

Its management may require partial or complete nail removal if adequate drainage cannot otherwise be achieved.

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Diagnosis

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Signs and Symptoms

Typical findings include:

Redness

Swelling

Tenderness

Pain along one side of the nail fold

If an abscess is present, there may be:

Fluctuance

Purulent drainage

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Physical Examination

Examine the entire fingertip and nail apparatus.

Assess for:

Lateral nail-fold swelling

Proximal nail-fold involvement

Subungual pus

Tenderness or fluctuance in the fingertip pulp

This helps distinguish uncomplicated paronychia from:

Felon

Eponychia

Subungual abscess

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Laboratory Tests

Laboratory studies are usually unnecessary for uncomplicated localized paronychia.

They may be considered when:

The infection is severe

The infection is spreading

The patient is immunocompromised

Systemic infection is suspected

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Cultures

Routine culture of drained pus is not always necessary in a simple uncomplicated case.

Culture becomes more useful when:

The infection is recurrent

Treatment has failed

There is extensive cellulitis

Unusual organisms are suspected

The patient is significantly immunocompromised

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Imaging

Imaging is not routinely required initially.

Radiographs may be useful when the infection is:

Chronic

Aggressive

Associated with trauma

Unresponsive to appropriate treatment

or when there is concern for:

Foreign body or osteomyelitis.

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Chronic Infection and Osteomyelitis

Longstanding infection may produce radiographic findings such as:

Cortical erosion

Bone resorption

or other changes compatible with:

Osteomyelitis.

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Pathological Findings

Acute paronychia usually demonstrates:

Acute inflammatory changes

with neutrophilic infiltration and purulent material.

Staphylococcus aureus is a common causative organism.

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Differential Diagnosis

Important alternatives include:

Eponychia

Felon

Subungual abscess

Herpetic whitlow

Mucous cyst

Psoriasis

Squamous cell carcinoma

Melanoma

Digital papillary adenocarcinoma

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Herpetic Whitlow

Herpetic whitlow can mimic paronychia but typically presents with:

Grouped vesicles

Burning pain

Viral-type lesions

Incision and drainage should be avoided when herpetic whitlow is suspected.

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Treatment

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Early Acute Paronychia Without Abscess

When there is:

Erythema and tenderness without a drainable collection, treatment may include:

Warm soapy soaks

Local wound care

and, when clinically indicated,

Oral antibiotics.

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Warm Soaks

Warm soaks may be performed several times daily to:

Promote drainage

Reduce swelling

Improve comfort

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Abscess

Once a fluctuant abscess has formed, the key treatment is:

Incision and drainage.

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Anesthesia

A:

Digital nerve block

with local anesthetic may be used before drainage.

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Drainage

The abscess can be drained using:

A small scalpel incision

or

A needle or blunt instrument

depending on the size and location.

A blunt instrument may be used to gently elevate the nail fold and open the infected space.

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Irrigation

After drainage, the wound may be irrigated with:

Saline solution

to remove residual purulent material and debris.

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Septae and Loculations

Any loculated collection should be gently opened so that:

Pus can drain completely.

Forceful deep probing should be avoided.

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Nail Removal

If pus extends beneath the nail, treatment may require:

Removal of the lateral portion of the nail plate

or, for a large subungual abscess,

Partial or complete nail removal.

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Dressings

A nonadherent dressing may be placed beneath or around the nail fold after drainage.

If part of the nail plate is removed, the nail fold may be protected with:

Nonadherent sterile gauze or another spacer.

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Antibiotics After Drainage

In a healthy patient with:

A localized uncomplicated abscess

that has been adequately drained and can be followed closely, routine antibiotics may not always be necessary.

Antibiotics are more appropriate when there is:

Cellulitis

Immunosuppression

Systemic symptoms

Incomplete drainage

High-risk comorbidity

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Medication

When antibiotics are indicated, therapy should cover typical skin flora.

Common oral options include:

Cephalexin

Amoxicillin-clavulanate

Clindamycin

Trimethoprim-sulfamethoxazole

Choice depends on:

Allergy history

Local resistance patterns

Concern for MRSA

Clindamycin or trimethoprim-sulfamethoxazole may be considered when MRSA is a concern.

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Chronic Paronychia

Chronic paronychia is generally defined as inflammation lasting:

More than 6 weeks.

It commonly occurs in individuals with repeated exposure to:

Water

Detergents

Chemical irritants

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Pathophysiology of Chronic Paronychia

Chronic disease is often primarily an:

Irritant or inflammatory dermatitis

rather than a persistent bacterial infection.

Fungal organisms may colonize the affected nail fold, but colonization does not necessarily mean that antifungal therapy is required.

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Chronic Paronychia Treatment

Management focuses on:

Avoiding irritants

Keeping the hands dry

Using protective gloves

Applying topical corticosteroids

Potential causative medications should be reviewed when appropriate.

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Surgical Treatment for Chronic Disease

Severe or refractory chronic paronychia may require procedures such as:

Eponychial marsupialization

or

Temporary reflection of the proximal nail fold

to allow the chronically inflamed tissue to heal.

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Surgery

Most acute paronychias do not require formal operating-room surgery.

They can usually be treated with:

Conservative care

or

Minor drainage under local anesthesia.

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Nail Deformity

Nail removal may be considered when there is:

Marked nail deformity

Persistent subungual infection

Inadequate drainage beneath the nail

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Follow-Up

The patient should generally be reassessed within approximately:

48 hours

after drainage or initiation of treatment.

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Patient Monitoring

At follow-up, assess for:

Reduction in pain

Improvement in redness and swelling

Resolution of drainage

Return of normal finger use

Worsening symptoms should prompt reassessment for:

Persistent abscess

Felon

Deep infection

Osteomyelitis

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Prognosis

The prognosis is generally:

Excellent with appropriate treatment.

Most acute infections resolve without long-term consequences.

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Complications

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Extension Into the Finger Pulp

Progression into the fingertip pulp may produce a:

Felon, which can require more extensive drainage.

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Osteomyelitis

Untreated or prolonged infection may spread to the:

Distal phalanx

and produce osteomyelitis.

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Nail Deformity

Infection or surgical injury involving the nail matrix may result in:

Permanent or temporary nail deformity.

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Progressive Soft-Tissue Infection

Cellulitis may spread proximally if infection is not controlled.

This is more concerning in patients with:

Diabetes

Immunosuppression

or

Peripheral vascular disease.

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Key Principle

Paronychia is a common infection or inflammatory disorder of the nail fold, usually following disruption of the protective nail barrier.

Management depends primarily on whether:

A drainable abscess is present.

Early cases without abscess may respond to:

Warm soaks and local care, whereas abscess formation requires:

Prompt drainage, with antibiotics reserved for selected patients with cellulitis, systemic disease, or other high-risk features.