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Original Investigation
May 10, 2019

Risk of Serious Infection in Patients Receiving Systemic Medications for the Treatment of Psoriasis

Author Affiliations
  • 1Department of Dermatology, Beth Israel Deaconess Medical Center, Boston, Massachusetts
  • 2Harvard Medical School, Boston, Massachusetts
  • 3Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women’s Hospital, Boston, Massachusetts
  • 4Department of Epidemiology, University of North Carolina at Chapel Hill
JAMA Dermatol. 2019;155(10):1142-1152. doi:10.1001/jamadermatol.2019.1121
Key Points

Question  What are the risks of serious infection with systemic medications used for the treatment of psoriasis?

Findings  In this comparative cohort study of 107 707 patients, we found a decreased risk of serious infection among users of apremilast, etanercept, and ustekinumab when compared with methotrexate.

Meaning  Health care professionals should consider risk of infection when choosing a systemic treatment for patients with moderate-to-severe psoriasis.


Importance  There is a need for better understanding of the comparative safety of systemic medications used in the treatment of psoriasis.

Objective  To compare the risk of serious infection associated with biologic and nonbiologic systemic medications in patients with psoriasis.

Design, Setting, and Participants  An observational cohort study was conducted using medical and outpatient pharmacy claims from 2 large US health insurance claims databases from January 1, 2003, through September 30, 2015. We included patients with a diagnosis of psoriasis who were new users of systemic medications for psoriasis.

Exposures  Prescription claims for acitretin, adalimumab, apremilast, etanercept, infliximab, methotrexate, or ustekinumab.

Main Outcomes and Measures  The primary outcome was serious infection, defined by inpatient discharge diagnosis International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes. Cox proportional hazards regression was used to compare rates of serious infection for each exposure (acitretin, adalimumab, apremilast, etanercept, infliximab, and ustekinumab) with the referent group (methotrexate). We used pairwise 1:1 propensity score (PS) matching to adjust for potential confounders, which were assessed during a 180-day baseline period prior to study drug initiation. Results from the 2 databases were pooled via fixed-effects analysis.

Results  The databases included 31 595 patients in the Optum Clinformatics Data Mart and 76 112 patients in Truven MarketScan who were new users of acitretin, adalimumab, apremilast, etanercept, infliximab, methotrexate, and ustekinumab. Users of acitretin, apremilast, infliximab, and methotrexate were older and had higher baseline comorbidity scores than subcutaneous biologic users (adalimumab, etanercept, and ustekinumab). The pooled PS-matched analysis yielded a decreased rate of overall serious infection in users of apremilast (hazard ratio [HR], 0.50; 95% CI, 0.26-0.94), etanercept (HR, 0.75; 95% CI, 0.61-0.93), and ustekinumab (HR, 0.65; 95% CI, 0.47-0.89) compared with methotrexate. We did not find a different rate of overall serious infection among users of acitretin, adalimumab, and infliximab compared with methotrexate. Subanalysis by type of serious infection showed a significantly increased risk of cellulitis among users of acitretin compared with methotrexate (PS-adjusted HR, 1.76; 95% CI, 1.11-2.80).

Conclusions and Relevance  Among patients with psoriasis treated with systemic medications in 2 large US claims databases, new users of apremilast, etanercept, and ustekinumab had a decreased rate of serious infection compared with methotrexate.