Pain evaluation and control during and following the treatment of hypertrophic scars and keloids by contact and intralesional cryosurgery - a preliminary study

Background Intralesional cryosurgery effectively treats hypertrophic scars and keloids (HSK), but pain experienced by the patient during treatment can limit the application of cryosurgery. Objectives To characterize the pain response during cryosurgical treatment of HSK, and to evaluate the pain experienced during contact and intralesional cryosurgery that employs a pain-control protocol. Methods Twenty-nine patients (17 women, 12 men) aged 17 years and older (mean ages 31.9 +/- 12.5 and 38.9 +/- 18.6 years, respectively, P = 0.24), who were treated for a total of 36 HSKs by intralesional (n = 20; 22 cryotreatments) or contact (n = 9; 14 cryotreatments) cryosurgery were evaluated. The pain-control protocol involved oral pain-relief tablets (Dipyrone) and translesional local anaesthesia with Bupivacaine hydrochloride 0.5%. Pain evaluation according to the Visual Analogue Scale (VAS) (0-10 cm) was compared between the two groups at three time points: during cryosurgery, immediately after it, and 4 h later. Scores 3 cm were considered to define the ` zone of analgesic success'. These results were comparedwith control data (contact cryosurgerywithout a pain-control protocol; n = 56). Results Pain in the intralesional group was significantly lower than that in the contact group during and immediately after cryotreatment. During: mean VAS = 1.68 +/- 2.21 vs. 5.07 +/- 4.01 cm; median VAS = 0.5 vs. 5.5 cm, respectively; P < 0.0001. Immediately after: mean VAS = 1.22 +/- 1.77 vs. 5.38 +/- 3.81 cm; median VAS = 0 vs. 6.0 cm, respectively; P = 0.001. The control group had more pain during treatment (mean VAS = 5.34 +/- 2.31, median = 6.0) and 4 h later (mean = 3.79 +/- 2.35, median = 4.0) than the intralesional group (P < 0.0001 and P = 0.988, respectively). The pain level in the control group during the cryotreatment did not differ from that in the contact group (P = 0.988). In the intralesional, contact and control groups analgesic success (VAS <= 3 cm) was achieved in 77.3%, 35.7% and 33.9%, respectively, of cases (P = 0.002) during cryotreatment, and in 54.5%, 42.9% and 33.9%, respectively, of cases 4 h after treatment (P = 0.24). Conclusions The pain-control protocol significantly reduced pain severity to tolerable levels (VAS <= 3 cm) during and following intralesional and contact cryosurgery. Intralesional cryosurgery caused the least pain during and immediately after treatment.