Diagnosis and Management of Ingrown Nail (Onychocryptosis) [เล็บขบ]

1️⃣ Diagnosis: Ingrown Nail (Onychocryptosis)

Definition

An ingrown nail occurs when the edge of the nail plate penetrates the periungual skin, causing inflammation ± infection.

Common Sites

• ✅ Great toe (most common)
• Less common: fingers (often from trauma, nail biting)

Risk Factors (Exam favorite ❗)

• Improper nail trimming (rounded edges ❌)
• Tight shoes / high heels
• Repeated trauma
• Hyperhidrosis
• Obesity
• Diabetes mellitus
• Nail biting (fingers)
• Poor foot hygiene

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2️⃣ Clinical Features

Symptoms

• Pain at nail margin
• Redness, swelling
• Tenderness
• Discharge (pus) → suggests infection
• Difficulty walking (toe)

Physical Examination

• Erythema at lateral nail fold
• Edema
• Granulation tissue (proud flesh)
• ± purulent discharge
• Nail edge visibly embedded

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3️⃣ Severity Classification (IMPORTANT FOR MANAGEMENT)

Stage I – Mild (Inflammatory)

• Pain
• Mild erythema
• No pus

Stage II – Moderate (Infected)

• Increased pain
• Swelling
• Purulent discharge
• Local infection

Stage III – Severe

• Chronic inflammation
• Granulation tissue
• Recurrent infection
• Nail deformity

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4️⃣ Management Overview (OPD CASE ✅)

👉 Most ingrown nails are managed as OPD

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5️⃣ Conservative Management (Stage I)

Non-pharmacological (FIRST LINE)

• Warm saline soak 15–20 min, 2–3×/day
• Proper nail trimming (straight cut ❗)
• Cotton wick or dental floss under nail edge
• Avoid tight shoes
• Keep area dry and clean

NSAIDs (Pain control)

• Ibuprofen (400 mg) PO tid pc, 3–5 daysOR
• Paracetamol (500 mg) PO qid prn

📌 Reason: Reduce pain and inflammation 📌 Exam pearl: NSAIDs do NOT treat infection

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6️⃣ When to Use Antibiotics ❗

Antibiotics are NOT routinely indicated

❌ No antibiotics in Stage I without infection

Indications for Antibiotics (Stage II)

• Purulent discharge
• Spreading cellulitis
• Fever
• High-risk patient (DM, immunocompromised)

Common Pathogens

• Staphylococcus aureus
• Streptococci

Antibiotic Choices (OPD)

First-line

• Amoxicillin-clavulanate (875/125 mg)PO bid pc × 5–7 days

Penicillin allergy

• Cephalexin (500 mg) PO qid × 5–7 days
• Clindamycin (300 mg) PO tid × 5–7 days

📌 Guideline basis: IDSA Skin & Soft Tissue Infection guideline

💡 RDU note (important for exams):

Antibiotics are only needed if infection is present,but in exams, once pus is described → give antibiotics

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7️⃣ Indications for Nail Avulsion ❗❗ (VERY HIGH-YIELD)

Absolute Indications

✅ Stage III disease ✅ Recurrent ingrown nail ✅ Failure of conservative treatment ✅ Granulation tissue ✅ Severe pain with infection ✅ Nail deformity

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8️⃣ Nail Avulsion (Definitive Treatment)

Types

1. Partial nail avulsion (preferred)
2. Total nail avulsion (rare)
3. Partial avulsion + phenolization (to prevent recurrence)

Procedure (Exam Knowledge)

• Digital nerve block
• Remove lateral nail edge
• Apply phenol 88% to nail matrix (chemical matricectomy)

📌 Recurrence rate

• Without phenol: high
• With phenol: <10%

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9️⃣ Post-Procedure Management

Medications

• NSAIDs for pain
• Antibiotics only if infection present

Wound Care

• Daily dressing
• Keep clean and dry
• Elevation

Follow-up

• OPD follow-up in 5–7 days
• Watch for infection signs

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🔑 Exam Summary Table

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🧠 Memory Pearl (Mnemonic)

“PAIN → PUS → PULL”

• Pain only → Conservative
• Pus → Antibiotics
• Pull the nail → Avulsion