Is blanching the visual endpoint for intralesional steroid injection of a keloid scar?

Blanching as the Visual Endpoint for Intralesional Steroid Injection of Keloids

Yes, blanching is the recommended visual endpoint when injecting intralesional corticosteroids into keloid scars. This indicates adequate dermal infiltration and proper distribution of the medication throughout the lesion.

Technical Injection Guidance

Blanching as the Endpoint

• Blanching serves as the clinical marker of successful infiltration when administering intralesional triamcinolone acetonide into keloid tissue 1
• An international consensus of keloid experts (65% agreement) established blanching as the endpoint of successful infiltration during intralesional corticosteroid administration 2
• The entire lesion and 1-2 mm of surrounding normal-appearing skin must be infiltrated until blanching is visible 3

Proper Injection Technique

• Inject 0.05-0.1 mL per site, which treats approximately a 0.5 cm diameter area of the lesion 1
• Use 25-27 gauge needles for adequate tissue penetration while minimizing discomfort 1, 2
• The needle should be placed just beneath the dermis, within the upper subcutis, to maximize local effect and limit systemic absorption 1
• Avoid subcutaneous injection, as this would be ineffective despite being innocuous 3
• Inject under pressure as the needle is advanced; initial dermal injection may meet with resistance that decreases with subsequent sessions 3

Standard Dosing Protocol

• Triamcinolone acetonide 40 mg/mL (TAC-40) is the standard concentration for keloids 1, 2
• Administer at maximum of 80 mg per month at intervals of 4 weeks 2
• For smaller or thinner lesions, lower concentrations of 5-10 mg/mL may be used to reduce atrophy risk 1
• Continue injections every 3-4 weeks until maximum therapeutic response is achieved 1

Critical Safety Considerations

Anatomic Contraindications

• Do not inject keloids on fingers, nose, ears, eyelids, near the lips, or anywhere vascular compromise could be of concern 3
• These locations carry risk of tissue necrosis or vascular complications from high injection pressures

Common Adverse Effects

• Skin atrophy is the most consistent adverse effect, especially with higher concentrations 1
• Pigmentary alterations and hypertrichosis may occur 1
• Pain at the injection site commonly limits the number of injections per session 1
• Transient Cushingoid features can occur with larger total doses or multiple injection sites due to systemic absorption 1

Serious but Rare Complications

• Adrenal suppression has been reported when cumulative doses exceed 4 mg/kg body weight 4, 1
• Central retinal artery embolization has been rarely reported, usually after injection into upper eyelid lesions, likely related to high injection pressures 4

Pain Management

• Apply topical anesthetic (e.g., EMLA cream) before injection to reduce pain and improve patient tolerance 3, 1
• Young children may require general anesthesia for the procedure 3
• Patient discomfort is the primary limiting factor for the number of injection sites that can be treated in a single visit 1

Clinical Pearls

• Multiple passes may be needed in very firm keloids prior to achieving adequate infiltration 2
• Use 1 mL syringes for better control of injection volume 2
• Ensure even distribution of steroid throughout the entire keloid tissue for best outcomes 1
• The beneficial effect of a single treatment course typically persists for about 9 months 1