What is the likely diagnosis and treatment for a female patient with redness, joint pain, and clear drainage around the knuckle of her right index finger, which has worsened over time and is accompanied by pain when bending the finger?

Acute Paronychia with Possible Abscess Formation

This patient has acute paronychia with probable abscess formation requiring immediate incision and drainage, along with warm soaks and consideration of oral antistaphylococcal antibiotics. 1, 2

Clinical Diagnosis

The presentation is classic for acute paronychia:

• Redness and swelling around the knuckle (proximal nail fold) that has progressively worsened over days 2
• Joint pain with finger flexion indicating inflammation extending to periarticular tissues 1
• Clear drainage suggesting either early purulent collection or serous fluid from the inflamed nail fold 1, 3

The "clear drainage" is a critical finding—this likely represents early abscess formation or inflammatory exudate, and the progression from simple redness to drainage with worsening pain indicates the infection is advancing beyond the superficial stage. 2, 3

Immediate Management Algorithm

Step 1: Assess for Abscess

• If fluctuance is present or drainage is occurring spontaneously, incision and drainage is mandatory 1, 2, 3
• The presence of visible drainage in this case strongly suggests abscess formation requiring surgical intervention 3
• Do not delay drainage with antibiotics alone when pus is present 1, 4

Step 2: Drainage Technique

• For simple paronychia with abscess, perform a simple incision approach by lifting the nail fold away from the nail plate 3
• If the abscess extends beneath the nail, a single incision along the lateral nail fold or partial nail plate removal may be required 3
• Ensure adequate drainage—inadequate drainage is the most common cause of treatment failure 4

Step 3: Antibiotic Therapy

• Oral antistaphylococcal antibiotics are indicated when there is surrounding cellulitis, systemic symptoms, or immunocompromise 1, 2
• Given the progressive nature with joint pain and worsening redness, antibiotics are warranted here 2
• First-line options include cephalexin or dicloxacillin, targeting Staphylococcus aureus and Streptococcus species 1, 2
• Consider MRSA coverage (trimethoprim-sulfamethoxazole or doxycycline) if risk factors present or if initial therapy fails 1

Step 4: Adjunctive Measures

• Warm water or Burow solution soaks 3-4 times daily to promote continued drainage and reduce inflammation 2, 3
• Splinting and elevation to reduce pain and swelling 1
• Tetanus prophylaxis if immunization status is not current 1

Critical Pitfalls to Avoid

Do not treat with antibiotics alone when drainage is present—this represents established abscess requiring surgical drainage. 1, 3 Antibiotics without drainage will fail and risk progression to deeper structures including flexor tenosynovitis, which is a surgical emergency. 1

Do not confuse this with chronic paronychia, which develops over weeks to months, lacks acute purulent drainage, and is treated primarily with irritant avoidance and topical steroids. 2 The acute onset over days with purulent drainage confirms acute bacterial infection. 2

Ensure adequate follow-up within 24-48 hours to assess response to drainage and antibiotics. 4 Failure to improve suggests inadequate drainage, resistant organisms, or progression to deeper infection requiring more aggressive intervention. 1, 4

When to Suspect Deeper Infection

If the patient develops:

• Fusiform swelling of the entire finger (suggests flexor tenosynovitis) 1
• Pain with passive extension of the finger (Kanavel's sign) 1
• Fever or systemic toxicity 1

These findings mandate immediate surgical consultation for possible flexor sheath irrigation and parenteral antibiotics, as pyogenic flexor tenosynovitis can cause permanent tendon damage within hours. 1