Management of Paronychia

Paronychia is inflammation/infection of the proximal and lateral nail folds. Management differs based on whether it is acute (bacterial) or chronic (fungal/irritant), and whether an abscess has formed.

Paronychia stages: abscess at side of nail (1), infection raised under eponychium (2), subeponychial and subungual abscess (3)

Cross-sections showing progression: abscess at nail side (1), raised under eponychium (2), full subeponychial/subungual abscess (3)

Causative Organisms

Type	Common Pathogens
Acute bacterial	S. aureus (most common), streptococci, CA-MRSA
Oral flora exposure (nail biting, finger sucking)	Anaerobes, gram-negative bacilli
Chronic	Candida albicans, mixed flora
Viral (herpetic whitlow)	Herpes simplex virus type 1 or 2

In children, anaerobes are frequent due to finger sucking and nail biting. A group A beta-hemolytic streptococcal paronychia can develop from thumb sucking with concurrent pharyngitis.
Cases have been reported with antiretroviral therapy for HIV and EGFR inhibitors (e.g., amivantamab, cetuximab).
Studies show ~25% anaerobic, 25% aerobic, and 50% mixed aerobic/anaerobic causation.

Acute Paronychia

Stage 1: Cellulitis (No Abscess)

Warm soaks 3 times daily (warm water or chlorhexidine soaks)
Oral antibiotics: first-generation cephalosporin (e.g., cephalexin) or antistaphylococcal penicillin (e.g., dicloxacillin)
If anaerobes/gram-negatives suspected (oral flora exposure): oral clindamycin or amoxicillin-clavulanate (Augmentin)
Topical antibiotics with or without topical corticosteroids can be used
Incision has no value at this stage

Stage 2: Abscess Formed

Drainage is the definitive treatment and is usually quickly curative.

Key principle: A paronychia is not a true cutaneous abscess but a pus collection in the potential space between the cuticle and the proximal nail - adequate drainage can almost always be achieved by lifting the eponychial fold without formal skin incision.

Drainage procedure:

Perform a digital nerve block for anesthesia
Soften the eponychium with a warm soak
Advance a No. 11 scalpel blade, scissors, or a 21-23 gauge needle parallel to the nail and under the eponychium at the point of maximal swelling
Allow pus to drain - no packing or sutures usually needed
Dress loosely

If abscess involves one corner only: Incise at that corner, angling the knife away from the nail bed (to avoid a later nail ridge).

If abscess has spread under the nail: A second incision on the opposite side + fold the proximal skin back + excise the proximal one-third of the nail. Pack loosely with iodoform gauze for 48 hours.

If subungual abscess extends further: Nail removal may be required (rarely needed as initial treatment).

A simple nick through the most translucent/fluctuant area is often all that is required.

Post-drainage antibiotics: Case studies suggest antibiotics are probably unnecessary in most drained cases. Reserve for significant cellulitis, immunocompromised patients, or comorbid conditions.

Chronic Paronychia

Caused by repeated mechanical/environmental trauma (water, irritants) that breaks down the cuticle barrier
Features: edema and erythema of the proximal nail fold, absence of cuticles, Beau lines, nail plate surface abnormalities
Often colonized by Candida albicans

Treatment:

Protective measures: cotton-lined rubber gloves to avoid contact with water and irritants
Topical steroids (e.g., betamethasone) to reduce inflammation
Topical antifungals (e.g., clotrimazole, miconazole)
Topical antimicrobials
Avoid cuticle manipulation

Herpetic Whitlow (Viral Paronychia) - Key Differential

Caused by HSV-1 or HSV-2; common in healthcare workers and immunocompromised patients
Presents with localized swelling and clear vesicle formation, lymphangitis, lymphadenopathy
Diagnosis: viral culture, Tzanck smear, serum antibody titers
I&D is CONTRAINDICATED (can disseminate or cause bacterial superinfection)
Treatment: Supportive; antivirals (acyclovir/valacyclovir) if within 48 hours of onset; suppressive antiviral therapy for recurrent cases

Summary Table

Situation	Treatment
Early cellulitis, no abscess	Warm soaks + oral antistaphylococcal antibiotics
Definite abscess	Digital block + drainage (elevate eponychium / needle/No.11 blade)
Abscess with subungual extension	Drainage + partial nail removal (proximal 1/3)
Chronic (fungal)	Protective measures + topical steroids + topical antifungals
Herpetic whitlow	Supportive; antivirals early; NO I&D
MRSA concern	TMP-SMX or clindamycin

Sources: Roberts and Hedges' Clinical Procedures in Emergency Medicine, 6e, p. 888-889; Campbell's Operative Orthopaedics 15e, 2026; Pfenninger and Fowler's Procedures for Primary Care, 3e; Goldman-Cecil Medicine, International Ed.

This is a shared conversation. Sign in to Orris to start your own chat.