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
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
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
4️⃣ Management Overview (OPD CASE ✅)
👉 Most ingrown nails are managed as OPD
| Stage | Main Treatment |
| I | Conservative |
| II | Conservative + Antibiotics |
| III | Nail avulsion (± phenol) |
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
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
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
8️⃣ Nail Avulsion (Definitive Treatment)
Types
- Partial nail avulsion (preferred)
- Total nail avulsion (rare)
- 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%
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
🔑 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 |
🧠 Memory Pearl (Mnemonic)
“PAIN → PUS → PULL”
- Pain only → Conservative
- Pus → Antibiotics
- Pull the nail → Avulsion