What are the recommended treatments, including specific drug choices, dosages, and duration, for acute bacterial paronychia and chronic paronychia?

Paronychia Treatment: Dosing and Duration

Acute Bacterial Paronychia

For acute bacterial paronychia, drainage alone cures 98% of cases in healthy adults without systemic antibiotics; reserve oral antibiotics only for severe infection (fever, lymphangitis, cellulitis beyond nail fold), immunocompromised patients, or inadequate drainage. 1

Initial Management (Grade 1 - Mild)

• Apply warm water soaks for 15 minutes, 3-4 times daily as first-line therapy 1, 2
• Alternatively, use white vinegar soaks (1:1 dilution with water) for 15 minutes daily 1, 2
• Apply topical povidone-iodine 2% twice daily to the affected area 3, 2
• Combine with mid-to-high potency topical corticosteroid ointment to nail folds twice daily to reduce inflammation 1, 3, 2
• Add topical antibiotics combined with corticosteroids 1, 3
• Reassess after 2 weeks; if no improvement, escalate to Grade 2 treatment 3, 2

Moderate Infection (Grade 2) - When Oral Antibiotics Are Indicated

Obtain bacterial/viral/fungal cultures before initiating antibiotics if infection is suspected 1, 3, 2

First-Line Oral Antibiotic Choices:

• Cephalexin 500 mg four times daily for 7-10 days (covers MSSA and streptococci) 1
• Amoxicillin-clavulanate 875/125 mg twice daily for 7-10 days (broader coverage including anaerobes) 1, 2
• Alternative: Dicloxacillin 500 mg four times daily for 7-10 days 1

For Penicillin-Allergic Patients:

• Clindamycin 300-450 mg three times daily for 7-10 days (covers staphylococci, streptococci, and anaerobes) 1
• Alternative: Doxycycline 100 mg twice daily 1

For Suspected or Confirmed MRSA:

• Trimethoprim-sulfamethoxazole (TMP-SMZ) 1-2 double-strength tablets twice daily (bactericidal against MRSA) 1, 2
• Alternative: Clindamycin 300-450 mg three times daily, with caution for inducible resistance in erythromycin-resistant strains 1

Severe Infection (Grade 3) - Surgical Intervention Required

• Abscess formation mandates drainage via instrumentation with hypodermic needle or wide incision with scalpel 1, 2
• Partial nail avulsion may be necessary for refractory cases with pyogenic granuloma 2
• Combine drainage with appropriate oral antibiotics as above 1, 2

Critical Pitfall to Avoid:

Do not routinely prescribe systemic antibiotics without adequate drainage - surgical drainage alone achieves 98% cure rates in healthy adults, with only 2% recurrence when drainage is complete 1. The single failure in prospective data was attributed to inadequate surgical excision, not lack of antibiotics 1.

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Chronic Paronychia

Chronic paronychia (≥6 weeks duration) is primarily an inflammatory/irritant dermatitis, NOT an infectious process; avoid routine systemic antibiotics unless secondary bacterial infection is confirmed. 1, 4

First-Line Treatment:

• Apply mid-to-high potency topical corticosteroid ointment to nail folds twice daily 1, 2
• Alternative: Topical calcineurin inhibitors 4
• Keep hands and feet dry, avoid prolonged soaking in soapy water, and wear protective gloves during wet work 1
• Apply topical emollients daily to cuticles and periungual tissues 2
• Treatment duration: weeks to months are typically required 4

For Secondary Candida Superinfection (Present in 25% of Cases):

First-line: Topical imidazole lotions (clotrimazole or miconazole) applied to affected area 1, 2

For Nail Plate Invasion or Severe Candida Cases:

• Oral itraconazole 200 mg daily for minimum 4 weeks for fingernails, 12 weeks for toenails 1
• Alternative: Itraconazole pulse therapy 1
• Avoid terbinafine - it has limited and unpredictable activity against Candida species 1

For Refractory Chronic Paronychia:

• Topical timolol 0.5% gel twice daily under occlusion for 1 month has shown complete clearance in periungual pyogenic granulomas 2
• Alternative: Silver nitrate chemical cauterization or cryotherapy 2

Prevention Education (Essential for Chronic Cases):

• Trim nails straight across, not too short 1, 2
• Avoid nail biting and cutting cuticles 1, 2
• Wear comfortable, well-fitting shoes and cotton socks 2
• Apply emollients daily to cuticles 1, 2

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Key Clinical Pearls:

• Up to 25% of paronychia cases develop secondary Candida or bacterial superinfection involving both gram-positive and gram-negative organisms 1, 3, 2
• Avoid topical steroids if purulent drainage is present until infection is adequately treated 3
• Drug-induced paronychia (from chemotherapy/targeted therapy) results from altered keratinocyte differentiation, not primary infection - treat with topical povidone-iodine and corticosteroids, avoiding routine systemic antibiotics 1, 3
• Reassess all cases after 2 weeks; if no improvement, escalate therapy or consider dermatology/podiatry referral 3, 2