What is the diagnosis and treatment for a patient with a swollen finger after trauma to the skin around the nail, with the nail bed intact?

Diagnosis: Paronychia (Answer B)

This patient has acute paronychia—a painful erythematous inflammation with swelling and tenderness of the lateral nail folds that develops after trauma to the skin around the nail. 1

Why Paronychia and Not the Other Options

• Felon involves infection of the pulp space of the fingertip (the fleshy pad), not the nail fold area, and would present with tense swelling of the entire fingertip pad 2
• Onychomycosis is a chronic fungal infection requiring weeks to months to develop, presenting with nail thickening, discoloration, and friable texture—not acute swelling after recent trauma 3
• Cellulitis would involve broader soft tissue infection extending beyond the nail fold area, typically with spreading erythema and warmth 2

The history of pulling skin around the nail (trauma to the protective nail barrier) followed by swelling within days is classic for acute paronychia 1, 2

Treatment Algorithm

Initial Conservative Management (First-Line)

Start with antiseptic soaks and topical therapy:

• Implement warm water soaks for 10-15 minutes, 2-3 times daily, OR use dilute vinegar soaks (50:50 dilution with water) twice daily as an alternative 3, 4
• Apply topical 2% povidone-iodine twice daily to the affected area 1, 4
• Apply mid-to-high potency topical corticosteroid ointment to nail folds twice daily to reduce inflammation 3, 4
• Reassess after 2 weeks 1, 5

If No Improvement or Moderate-to-Severe Infection

Obtain cultures and consider oral antibiotics:

• Culture any purulent material to guide antibiotic therapy, as up to 25% of cases have secondary bacterial or mycological superinfection with both gram-positive and gram-negative organisms 1, 3
• Start oral antibiotics based on likely pathogens and local resistance patterns 2
• If initial antibiotic (e.g., cephalexin) fails, switch to broader spectrum coverage such as sulfamethoxazole-trimethoprim for MRSA coverage 5

If Abscess Present

Drainage is mandatory:

• Perform incision and drainage if fluctuance or abscess formation is present 2, 6
• Options range from instrumentation with a hypodermic needle to wider incision with a scalpel 2
• Oral antibiotics are usually not needed if adequate drainage is achieved unless the patient is immunocompromised 2

Refractory Cases (Grade 3 or Intolerable Grade 2)

Consider advanced interventions:

• Intralesional triamcinolone acetonide for recurrent or severe cases 3, 4
• Silver nitrate chemical cauterization for excessive granulation tissue 1, 4
• Partial nail avulsion may be necessary for severe cases 1, 5
• Consider doxycycline 100 mg twice daily for recurrent, severe, or treatment-refractory cases with follow-up after 1 month 3

Critical Prevention Measures to Prevent Recurrence

Patient education is paramount:

• Avoid nail-biting, finger-sucking, or cutting nails too short 3, 4
• Trim nails straight across and not too short 4, 5
• Apply daily topical emollients to cuticles and periungual tissues 3, 4
• Avoid repeated friction, trauma, and excessive pressure 4
• Wear protective gloves during activities involving water or chemicals 4, 5
• Keep hands dry and avoid excessive moisture exposure 3, 5

Common Pitfalls

• Don't assume all paronychia is purely bacterial—up to 25% have fungal superinfection, and viral or non-infectious causes exist 1, 7
• Don't prescribe antibiotics without drainage if an abscess is present—drainage is the definitive treatment 2
• Don't overlook occupational factors—patients with wet occupations (housekeepers, dishwashers, bartenders) are at higher risk for chronic paronychia if acute episodes don't fully resolve 3, 2
• Don't miss progression to osteomyelitis—monitor for worsening disease, as nail folds are anatomically close to phalanges 8