Combination Therapy for Psoriasis in the United States

May 2013 | Volume 12 | Issue 5 | Original Article | 546 | Copyright © May 2013

Scott A. Davis MAa and Steven R. Feldman MD PhDa-c

Center for Dermatology Research, Departments of aDermatology, bPathology, and cPublic Health Sciences, Wake Forest School of Medicine, Winston-Salem, NC

BACKGROUND: Psoriasis is treated with several classes of treatments that may be used in combination, but the ways combination therapies are used are not well characterized.
PURPOSE: To determine the frequency of prescribing calcipotriene and other psoriasis drugs in combination.
METHODS: Visits with a sole diagnosis of psoriasis were selected from 1990-2010 data from the National Ambulatory Medical Care Survey. The number of combination therapies used, the leading therapies in each class of medications, and the leading types used in combination were analyzed.
RESULTS: About 10.2 million of 20.3 million psoriasis visits used multiple treatments. The mean number of prescribed medications increased over time (P=.0003). The top 10 treatments included 6 topical steroids, calcipotriene, 2 other topicals, and methotrexate. The most common combinations were topical steroid plus other topical (15.0%), multiple topical steroids (11.5%), topical steroid plus vitamin D analogue (9.7%), and topical steroid plus systemic treatment (6.9%). Vitamin D analogues and systemic treatments were prescribed with increasing frequency over time, while fewer topical steroids were used, and use of other topicals did not change significantly.
LIMITATIONS: Visits with multiple diagnoses had to be excluded to ensure that the medications listed were for psoriasis.
CONCLUSIONS: Combination therapy is the most common way to treat psoriasis in the United States. The wide range of combination therapies prescribed may reflect increased attention to individualization of treatment to match patients’ diverse preferences.

J Drugs Dermatol. 2013;12(5):546-550.


Psoriasis patients are often frustrated with the treatment they receive.1-3 The quality-of-life impact of psoriasis is comparable to that of other major medical diseases such as arthritis, hypertension, and diabetes.4-6 The wide range of variation in patient preferences, combined with the complex patient psychology involved, continues to contribute to suboptimal treatment.5,7,8 Low motivation, which contributes to poor adherence and poor outcomes, can result from fear of medication, dissatisfaction with the cosmetic effects of medications, or simply lack of hope that psoriasis can be effectively controlled.3,8
Many factors contribute to the need for physicians to have a large arsenal of treatments available for psoriasis. Different patients prefer different vehicles, and patients may even prefer one vehicle for one body site and a different vehicle for another.9,10 Superpotent corticosteroids are ideal for some body sites but cannot be safely used in more sensitive areas.11 Most corticosteroids cannot be safely used for long periods of time and have to be replaced with other medications, such as calcipotriene, after a few weeks.11 Some patients have insurance that covers the most expensive branded products, while others do not. Multiple products used together, such as calcipotriene combined with topical steroids, often have synergistic effects, but many patients are more adherent to a simpler regimen.12 All these factors dictate that individualized treatment of psoriasis is essential. Despite occasional pressures to standardize psoriasis treatment, the latest guidelines continue to recognize that a wide range of monotherapies and combination therapies should be part of the physician’s treatment repertoire.11,13
Treatment of psoriasis continues to evolve rapidly with the introduction of new treatments almost every year. The combinations that are most often used have not been well characterized in recent years. The purpose of this study is to assess the frequency with which calcipotriene and other psoriasis drugs are used in combination.


The National Ambulatory Medical Care Survey (NAMCS), conducted by the National Center for Health Statistics, has collected data annually since 1989 on the utilization of ambulatory medical care services in the United States. Using a multistage probability sample design, the NAMCS collects data on a nationally representative sample of outpatient visits to nonfederally employed physicians who participate in direct patient care. Patient demographics, diagnoses, medications, and services provided are among the data recorded. Sampling weights are applied to make nationally representative frequency estimates.
This study analyzed all NAMCS visits from 1990 to 2010 with a sole diagnosis of psoriasis (ICD-9 code 696.1). Visits with other diagnoses were excluded to ensure that the prescribed medications were for psoriasis. Psoriasis medications were classified as topical steroids, vitamin D analogues, other topicals, and systemic treatments. Other topicals included calcineurin inhibitors, tar, anthralin, moisturizers, and keratolytics, including salicylic acid. Systemic treatments included systemic steroids, methotrexate, acitretin, cyclosporine, and biologics. Phototherapy treatments were not assessed in this