Localization of Treatment-resistant Areas in Patients With Psoriasis on Biologics

K.F. Hjuler; L. Iversen; M.K. Rasmussen; K. Kofoed; L. Skov; C. Zachariae


The British Journal of Dermatology. 2019;181(2):332-337. 

In This Article

Patients and Methods

Design and Protocol

The study was designed as an observational, noninterventional study. The skin and/or nail location of treatment-resistant psoriasis was investigated in patients with moderate-to-severe psoriasis treated for ≥ 6 months with apremilast or biologic agents. A partial or good response to the therapy was defined as obtaining a PASI ≥ 1 and ≤ 5. Any subsequent treatment modification or initiation of adjuvant therapy was decided at the physician's discretion and not mandated by the protocol.

Experienced PASI assessors in two university hospital dermatology clinics included consecutive patients in the study. Both sites used a uniform data collection method predefined in a data entry form in which the body area was divided into 26 regions and 20 nails.

The study was observational and assessed the treatment quality of approved biologic therapies. The Central Denmark Region Committees on Biomedical Research Ethics waived the requirement for informed consent after reviewing the protocol. The study has been registered with the Danish Data Protection Agency.

Study Population: Patients With Psoriasis

Inclusion criteria were ≥ 18 years of age, a formal diagnosis of chronic plaque psoriasis confirmed by a dermatologist, current and continuous treatment for ≥ 6 months with biologic agents (or apremilast) approved for psoriasis, and moderate-to-severe disease as defined by a PASI score of ≥ 10 before or at the time of treatment initiation. Furthermore, eligible patients were partial responders with a remaining treatment-resistant psoriasis disease burden, with a current PASI score ≥ 1 and ≤ 5. Quality of life was measuring by DLQI.

Statistical Analysis

Summary statistics were expressed as the mean ± SD for normally distributed variables. Non-normal variables were expressed as the median and the 25th–75th percentiles interquartile range. Associations between the DLQI and affected skin regions were assessed using the χ 2-test. To avoid a false discovery rate, analyses were adjusted using the Benjamini–Hochberg procedure.

Data were tested for normality using the D'Agostino–Pearson normality test. The level of statistical significance was set at α = 0·05. Graphs and statistical analyses were made in GraphPad Prism version 7·0 (GraphPad Software, San Diego, CA, U.S.A.) and Stata/IC version 12·1 for Mac (StataCorp LP, College Station, TX, U.S.A.).