Intralesional Corticosteroid Injection Methods in Keloids Lack Standardization

Randomized controlled trials (RCTs) evaluating intralesional corticosteroid administration (ICA) for keloids are characterized by incomplete reporting and substantial heterogeneity, which limit the ability to standardize treatment protocols and study designs. These findings were reported by investigators of a scoping review published in Dermatology.

According to the study authors, “Intralesional corticosteroid administration (ICA) is a first-line treatment in current practice, of which triamcinolone acetonide (TAC) is most commonly used.” They therefore sought to characterize methods for ICA for keloid treatment in RCTs.

They conducted a systematic search on MEDLINE, CENTRAL, EMBASE, and PubMed from inception to January 2022 for RCTs that included patients with keloids treated with intralesional corticosteroids. In order to include all relevant articles, no explicit outcomes were stated in the search, which was limited to studies in German, Dutch, French, and English. Two reviewers conducted title and abstract screening, and 2 reviewers independently evaluated full texts. Eligibility criteria included patients of any race, sex, and age with 1 or more keloids in any anatomical location, of any size, with any duration, and with any etiology. The investigators included only RCTs that involved intralesional corticosteroids.

A total of 38 RCTs were identified, 37 of which involved administration of TAC. Ten studies allowed for dosing comparisons per cm², varying from 1 mg to 20 mg. The maximum dose per session ranged from 20 mg to 80 mg. One study compared the effect of different doses of TAC directly, and 34 studies investigated different keloid therapies (the TAC group was the treatment arm in some studies and the control arm in other studies). The investigators noted that the primary focus for 3 studies was the effect of local anesthetics on injection pain.

Investigators identified weekly and monthly treatment intervals, with 4 weeks being the most common at 50%. In 20% of the RCTs, local anesthetics were administered. Needle size was reported in 11 studies and ranged from 26 gauge to 30 gauge. A 1-mL syringe was used in 4 studies. Injection level was described in 11 studies, and 10 studies reported blanching as the endpoint.

Numerous outcome measures were recorded (eg, height, volume, surface area, Vancouver Scar Scale [VSS], pain and itch scores, Patient and Observer Scar Assessment Scale [POSAS], and patient satisfaction and efficacy rates). Keloid size was documented in 12 studies, VSS in 10 studies, POSAS in 7 studies, and patient satisfaction in 8 studies. Follow-up of at least 6 months was only conducted in 6 studies. Adverse events were reported in 23 studies (unspecified in 11 of the studies), and 2 studies identified recurrence at 18 weeks and 1 year of follow-up.

According to the investigators, diagnostic criteria were not described in 24 of the included studies. They noted 6 studies presented separate data on keloids and hypertrophic scars, 3 of which did not specify criteria for distinction between them.

High risk of bias was found in 29 of the studies, most commonly for measurement of outcome.

Overall incomplete reporting and high heterogeneity were found, rendering the current literature not amenable to data synthesis. Review limitations include the inclusion of keloids of all sizes, locations, duration, and etiology, and unspecified definitions of keloids and hypertrophic scars leading to the possibility of combining data inappropriately.

Investigators concluded “There is incomplete reporting and substantial heterogeneity in many aspects of ICA and study design among RCTs.” They believe their review “underscores the urgent need for standardization of treatment protocol and study design to enhance and uniform research conduct among keloid studies.” They reiterated the need for future studies to use a uniform definition that does not yet exist.