Intralesional Steroid Injection Technique for Keloids
Inject triamcinolone acetonide at a concentration of 10-40 mg/mL directly into the keloid tissue using a small-bore needle (25-27 gauge), delivering 0.05-0.1 mL per injection site just beneath the dermis in the upper subcutis, with multiple injections spaced throughout the lesion to achieve even distribution. 1, 2, 3
Optimal Needle-Syringe Combination
Use a 1 mL polycarbonate syringe with a 25-gauge, 16 mm needle for the most ergonomic injection setup, as this combination requires significantly less force (25.0 N versus 40.0 N) to penetrate the dense keloid tissue compared to standard combinations. 4
Avoid larger caliber syringes and longer or smaller gauge needles, as these substantially increase the injection force required—potentially exceeding the maximum force that can be comfortably exerted, particularly for practitioners with smaller hands. 4
Injection Technique Details
Inject the triamcinolone suspension just beneath the dermis in the upper subcutis of the keloid, not into the superficial skin layers. 1, 2
Deliver 0.05-0.1 mL per injection site, which produces a therapeutic effect in approximately 0.5 cm diameter area. 1, 2
Space multiple injections throughout the keloid to ensure even distribution of the medication across the entire lesion, as uneven distribution may lead to incomplete response. 1
Shake the vial before use to ensure uniform suspension and inject without delay after withdrawal to prevent settling in the syringe. 3
Concentration and Dosing
Use triamcinolone acetonide at concentrations of 10-40 mg/mL, with most protocols employing 10 mg/mL for initial treatments. 2, 3, 5
The FDA label indicates that doses up to 40 mg for larger areas have usually been sufficient, though this represents the upper limit. 3
For immediate post-excision injection (to prevent recurrence), 10 mg/mL has been shown effective in suppressing collagen gene expression. 6
Treatment Schedule
Repeat injections every 3-4 weeks until the keloid flattens or shows maximal response, typically requiring multiple treatment sessions. 5, 7
Most patients require a series of injections rather than a single treatment to achieve optimal results. 3, 5
Critical Technical Considerations
Employ strict aseptic technique to avoid introducing infection into the keloid tissue. 3
Avoid injecting into blood vessels by using careful technique and aspirating before injection. 3
The density of keloid tissue makes injection physically challenging—expect significant resistance when advancing the needle and depressing the plunger. 4
Expected Outcomes and Recurrence
Expect 50-100% regression of the keloid with intralesional triamcinolone therapy, though response is variable among patients. 5, 7
Be aware that recurrence rates are approximately 33% at 1 year and 50% at 5 years, even with initially successful treatment. 5, 7
Combination therapy (surgical excision followed by immediate intralesional steroid injection) appears most efficacious for preventing recurrence, particularly when triamcinolone is injected into the wound bed immediately after keloid excision rather than waiting weeks. 8, 6
Common Adverse Effects to Monitor
Local skin complications include atrophy, pigmentary changes, and telangiectasia at injection sites, which are the most frequently reported adverse effects. 1, 2
Systemic effects (Cushingoid features, adrenal suppression) are rare with intralesional keloid injections but can occur with large doses exceeding 4 mg/kg. 1
Patient discomfort during injection is the main limitation to the number of injection sites that can be treated in a single session. 1