title: Intra-lesional injections of collagenase are ineffective in the treatment of keloid and hypertrophic scars.
abstract: The treatment of keloid and hypertrophic scars remains difficult. Enzymatic digestion of keloid scars has been previously proposed as an effective treatment strategy for reducing the volume of keloid scars. To test this, we administered intra-lesional injections of pure collagenase (between 600 and 4500 units for each scar) into the keloid and hypertrophic scars of seven human volunteers (five keloid and two hypertrophic scars). Five patients (three keloid and two hypertrophic) received more than one injection of collagenase. The treatment resulted in a temporary reduction in scar volume for three of the patients with keloid scars. However, scar volumes for these three patients returned to the same (or greater) levels after 6 months of follow-up. Treatment with collagenase produced no change in scar volume for the two patients with hypertrophic scar. Side effects were numerous and severe including; pain, swelling, blistering, ulceration and ecchymosis at the site of injection. One patient required admission to hospital for 48 h after the first injection. Maximum length of follow-up was 6 months. None of the seven patients completed the study and returned for final follow-up at 2 years. This pilot study suggests that treatment of keloid and hypertrophic scars with intra-lesional injections of collagenase is ineffective.
authors.affiliation: Mount Vernon Hospital, Northwood, Middlesex HA6 2RN, UK. mrkang@connectfree.co.uk
authors.forename: Norbert
authors.initials: N
authors.lastname: Kang
authors.forename: Branavan
authors.initials: B
authors.lastname: Sivakumar
authors.forename: Roy
authors.initials: R
authors.lastname: Sanders
authors.forename: Charles
authors.initials: C
authors.lastname: Nduka
authors.forename: David
authors.initials: D
authors.lastname: Gault
mesh_terms: D000328:Adult; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage / Q000009:adverse effects; D001768:Blister / Q000139:chemically induced; D002648:Child; D017439:Cicatrix, Hypertrophic / Q000188:drug therapy*; D004334:Drug Administration Schedule; D004359:Drug Therapy, Combination; D005260:Female; D005334:Fever / Q000139:chemically induced; D006801:Humans; D015552:Injections, Intralesional; D007627:Keloid / Q000188:drug therapy*; D008297:Male; D003012:Microbial Collagenase / Q000008:administration & dosage* / Q000009:adverse effects; D008875:Middle Aged; D010146:Pain / Q000139:chemically induced; D010865:Pilot Projects; D017211:Treatment Failure; D014222:Triamcinolone Acetonide / Q000008:administration & dosage / Q000009:adverse effects
chemical_list: D000893:Anti-Inflammatory Agents; D003012:Microbial Collagenase; D014222:Triamcinolone Acetonide