Optimal therapeutic dose protocol may result in more effective psoriasis laser treatment

An optimal therapeutic dose protocol with excimer laser for the treatment of plaque psoriasis yielded more effective dosing in fewer treatment sessions, according to a study.

“A newer method for determining the UVB treatment dose is the optimal therapeutic dose protocol, whereby the minimum blistering dose at which the patient develops microblisters is determined for each plaque,” Quinn Thibodeaux, MD, of the Psoriasis and Skin Treatment Center, University of California, San Francisco, and colleagues wrote. “This is a plaque-specific protocol where treatment doses are individualized for specific plaques.”

In a prospective, open-label pilot study conducted between July 2017 and June 2018, 13 patients aged 18 and older with at least one stable psoriatic plaque were included for analysis. After a treatment washout period, patients underwent a test dose period to determine optimal therapeutic dosage with a Multi-Micro Dose tip on the XTRAC excimer laser (Strata Skin Sciences). Follow-up of 24 to 48 hours was observed to evaluate minimum blistering dose. Treatment was then initiated at an excimer laser power 20% less than the minimum blistering dose. Patients were treated weekly with the same dose until plaque psoriasis was clear, almost clear or worsened. Treatment sessions were based on lesion location and plaque severity.

Modified Psoriasis Area and Severity Index (mPASI) scores saw improvement by the second treatment session, with 12 patients (92%) achieving mPASI-75 after an average of five treatment sessions and mPASI-50 after an average of four treatment sessions.

After treatment discontinuation, patients maintained mPASI-50 or greater for an average of 60 days. Follow-up questionnaire responses found no significant change in overall patient quality of life; however, there was an improvement in itchiness, soreness, painfulness or stinging of the skin.

“The [optimal therapeutic dose] protocol allowed the determination of the optimal dose for treating psoriasis plaques within an average of 2.4 sessions,” Thibodeaux and colleagues wrote. “The [optimal therapeutic dose] protocol with the [Multi-Micro Dose] tip allows adjusting the treatment dose with the excimer laser to specific plaques, resulting in more effective dosing levels and a lower frequency of treatment sessions.”– by Kate Burba

Disclosures: Thibodeaux reports no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.