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

Stage	Main Treatment
I	Conservative
II	Conservative + Antibiotics
III	Nail avulsion (± phenol)

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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

Topic	Key Point
Diagnosis	Clinical diagnosis
NSAIDs	Pain control only
Antibiotics	Only if infected
Most common pathogen	Staph aureus
Definitive treatment	Partial nail avulsion
Recurrence prevention	Phenolization
OPD vs IPD	OPD

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🧠 Memory Pearl (Mnemonic)

“PAIN → PUS → PULL”

• Pain only → Conservative

• Pus → Antibiotics

• Pull the nail → Avulsion