ABSTRACT
BACKGROUND: Psoriasis is a common and relapsing disease, which is both physically and psychologically disabling. Narrowband UVB (NB-UVB) is used in fair-skinned population in suberythemogenic doses with good results; however, in the darker skin population (skin types III, IV, V) erythemogenic doses have not been thoroughly investigated. AIM: A left-right bilateral comparative trial was carried out to compare the suberythemogenic dose of NB-UVB vs. erythemogenic dose in the treatment of dark-skinned psoriatic patients. PATIENTS AND METHODS: The study was conducted on 20 patients with chronic plaque psoriasis. The left side was treated with the dose causing minimal erythema [100% of minimal erythema dose (MED)] while the right side received 70% of this MED (suberythemogenic side). RESULTS: Our results revealed no statistically significant difference in PASI final and in the percentage of reduction of PASI score between both sides as well as the total number of sessions (P-value>0.05), while the total cumulative UVB dose on the suberythemogenic side was significantly lower (P-value<0.001). CONCLUSION: Our study recommends reducing the dose regimen of NB-UVB and consequently the cumulative UVB dose by using the suberythemogenic dosing schedule even in dark skin population.
