What is the proper technique for injecting a keloid with corticosteroid (e.g. triamcinolone acetonide) in a patient with a history of keloid formation or other skin conditions?

How to Inject a Keloid with Intralesional Corticosteroid

Recommended Corticosteroid and Concentration

Use triamcinolone acetonide at 40 mg/mL concentration for keloid injections, which is the specific concentration recommended by the American Academy of Dermatology for hypertrophic scars and keloids. 1 This concentration is notably higher than what is used for other dermatologic conditions and provides optimal efficacy for keloid treatment. 1

• For smaller or more sensitive keloids, concentrations of 10-20 mg/mL may be used to minimize adverse effects, though 40 mg/mL remains the standard. 1, 2
• Lower concentrations (5-10 mg/mL) can be considered for facial keloids or areas at higher risk for atrophy. 3, 4

Injection Technique

Inject the triamcinolone acetonide just beneath the dermis in the upper subcutis, not into the keloid substance itself. 3, 1, 2 This anatomical placement is critical for optimal drug distribution and therapeutic effect.

Volume and Dosing Protocol

• Inject 0.05-0.1 mL per injection site, which will produce a therapeutic effect in approximately 0.5 cm diameter area. 3, 2
• Multiple injections are typically required across the keloid surface to achieve adequate coverage. 3
• Repeat injections every 3-4 weeks until the keloid flattens or symptoms resolve. 3, 5
• Treatment typically requires 20-30 injections over 3-5 years for complete resolution, though some patients may respond faster. 6

Practical Injection Steps

• Shake the vial before use to ensure uniform suspension and inspect for clumping or granular appearance (agglomeration). 7
• Use strict aseptic technique throughout the procedure. 7
• Inject without delay after drawing up the medication to prevent settling in the syringe. 7
• Inject until the keloid tissue blanches, indicating adequate intralesional distribution. 3

Pain Management

Apply EMLA cream (lidocaine/prilocaine) as topical anesthesia prior to injection to minimize discomfort. 3, 2 This is particularly important as keloid injections are notoriously painful and can lead to treatment discontinuation.

• In young children or patients with extensive keloids requiring multiple injection sites, general anesthesia or sedation may be necessary. 3, 2
• Consider premedication with topical anesthetic 30-60 minutes before the procedure. 3

Absolute Contraindications

Do not inject triamcinolone in the following situations: 1

• Active infection at the injection site
• Previous hypersensitivity to triamcinolone
• Active tuberculosis or systemic fungal infections

Special Precautions and High-Risk Situations

Exercise particular caution in these scenarios, as they carry increased risk for adverse effects: 1

• Facial or intertriginous keloids - Higher risk for atrophy and telangiectasia
• Large or diffuse keloids - Difficult to achieve even distribution and increased systemic absorption risk
• Patients with uncontrolled diabetes, heart failure, or severe hypertension - Monitor closely for systemic effects
• Patients with history of keloid formation - Counsel that outcomes remain uncertain despite treatment 3

Common Adverse Effects and How to Minimize Them

The most common complication is skin atrophy at the injection site, which is dose-dependent. 4, 2 To minimize this risk:

• Use lower concentrations (10-20 mg/mL instead of 40 mg/mL) and smaller volumes when treating facial keloids or sensitive areas. 3, 1
• Ensure proper injection depth in the upper subcutis, not subcutaneous fat, as improper technique increases atrophy risk. 7
• Other potential adverse effects include telangiectasias, pigmentary changes, and folliculitis. 4, 2

Expected Outcomes and Recurrence

Complete flattening of keloids occurs in 50-100% of cases with intralesional corticosteroid therapy alone, but recurrence rates are significant. 5, 8

• Recurrence occurs in approximately 33% of patients at 1 year and 50% at 5 years. 5, 8
• Subjective symptom improvement (itching, pain) occurs in approximately 82% of patients. 6
• Objective improvement (flattening, size reduction) occurs in 63% of patients, with good or excellent results in 39%. 6

Combination Therapy Considerations

Triamcinolone combined with 5-fluorouracil (5-FU) is more effective and shows fewer adverse effects compared to either agent alone. 5, 9 This combination approach should be considered for recalcitrant keloids or those with previous treatment failure.

• Triamcinolone combined with verapamil also shows effectiveness with long-term stable results. 5
• Laser therapy (CO2, pulsed-dye, or Nd:YAG) combined with triamcinolone injections produces better results than laser alone. 5

Critical Pitfall to Avoid

Do not inject into the tendon substance or subcutaneous fat - always target the upper subcutis just beneath the dermis. 3, 7 Improper injection depth is the most common technical error and leads to subcutaneous fat atrophy without therapeutic benefit. 7