Pain-free intralesional injection of triamcinolone for the treatment of keloid.

Intralesional injection of triamcinolone acetonide (TA) for the treatment of keloid is painful, and lidocaine-mixed preparations are much the same. I have injected TA (10 mg/ml) at the speed of 3-6 ml/hour using an electric syringe pump 40 times for the treatment of 10 keloids, 18 times without lidocaine and 22 times with lidocaine. The 95% confidence intervals (CI) of the 100 mm visual analogue pain scale of the TA alone group and the lidocaine-mixed group were 2.0 to 9.5 mm and 1.0 to 6.7 mm respectively, suggesting that both are practically pain-free. The speed of injection is an important determinant of pain in intralesional chemotherapy. The injection should be extremely slow and lidocaine should be added for sensitive patients.