Conversion to positive tuberculosis test during etanercept treatment of psoriasis

Journal of Drugs in Dermatology, Oct, 2007 by William Sumner, Steven R. Feldman

Abstract

The use of tumor necrosis factor alpha inhibitors (TNF-[alpha]) for psoriasis has raised greater awareness of tuberculosis screening. Tuberculosis can be acquired during foreign travel and also within the US by exposure to infected persons. We present a patient who converted to a positive purified protein derivative test (PPD) during anti-TNF-[alpha] treatment of psoriasis. PPD testing prior to any immunosuppressive treatment may be prudent, especially considering the benign nature and low cost of the test. As illustrated by this case, one may wish to consider annual tuberculosis testing for these patients.

Introduction

The increasing use of tumor necrosis factor alpha inhibitors (TNF-[alpha]) for psoriasis has raised greater awareness of tuberculosis screening in dermatology. Tuberculosis is uncommon in the US compared to other countries. (1) Systematic follow-up and treatment of affected individuals and their contacts reduced the US prevalence over the past decade. Foreign born individuals account for a substantial proportion of tuberculosis cases occurring in the US. While the number of tuberculosis cases in the US is decreasing for both US-born and foreign-born persons, the decrease is less drastic among foreign-born persons. Hispanics (29%) now exceed non-Hispanic blacks (28%) as the racial/ethnic group with the largest percentage of total cases. (1) Hispanics and Asians each represent 40% of tuberculosis cases in foreign-born persons and together account for almost 45% of the overall national case total. (1) Tuberculosis should be considered in patients undergoing immunosuppressive treatment for their skin disease. Tuberculosis and other infections can be acquired during foreign travel and also within the US from exposure to infected persons. We present a patient who converted to a positive purified protein derivative test (PPD) during anti-TNF-[alpha] treatment of psoriasis.

Case Report

A 57-year-old male presented with widespread, severe psoriasis. He had previously been treated with topical corticosteroids, calcipotriene, ultraviolet light, and methotrexate. He had joint pain in his ankles and knees. He worked in construction in close contact with migrant Latino construction workers. There were typical psoriasiform plaques affecting 35% of his total body surface area. In preparation for anti-TNF-[alpha] treatment, a PPD test was done, which was negative. The patient was started on 50 mg etanercept twice weekly. His psoriasis and joint pain dramatically improved and, after 3 months of therapy, the etanercept was decreased to 50 mg once weekly. At a one-year return visit, the PPD was positive with a 15-mm area of induration.

Discussion

Tuberculosis has been a major problem in many societies. In the US, careful control efforts have helped reduce the incidence of the disease. Nevertheless, tuberculosis has not been eliminated. The areas of the country that are most affected--California, New York, Texas, and Florida--have a high influx of foreign-born people and account for 48% of all cases. Dermatologists should remain vigilant for latent tuberculosis and new exposure to tuberculosis, especially in patients on immunosuppressive treatment. Travel to endemic areas outside of the US with far higher tuberculosis rates may not be unusual for otherwise young, healthy psoriasis patients. We should also recognize that patients do not need to leave the US to be exposed to people from endemic areas. Screening with a PPD test before initiating anti-TNF-[alpha] therapy is a prudent measure. (2) A PPD test previous to immunosuppressive treatment is probably not excessive, especially considering the benign nature and low cost of the test. Moreover, as illustrated by this case, one may wish to consider annual tuberculosis testing for these patients.

Disclosure

The Center for Dermatology Research is supported by Galderma Laboratories, LP. Dr. Feldman has received support from Abbott, Amgen and Centocor.

References

1. CDC. Reported Tuberculosis in the United States, 2005. Atlanta, GA: U.S. Department of Health and Human Services, CDC, September 2006.

2. Tuberculosis Associated with Blocking Agents Against Tumor Necrosis Factor-Alpha--California, 2002-2003. Available at: http://www.cdc.gov/MMWR/preview/mmwrhtml/mm5330a4.htm. Accessed August 17, 2007.

ADDRESS FOR CONRESPONDENCE

Steven R. Feldman MD PhD

Dept. of Dermatology

Medical Center Boulevard

Winston-Salem, NC 27157-1071

Phone: 336-716-7740

Fax: 336-716-7732

e-mail: sfeldman@wfubmc.edu

William Sumner MD, (a) Steven R. Feldman MD PhD (b)

a. Private Practice, Concord, NC

b. Center for Dermatology Research, Department of Dermatology, Department of Pathology, Division of Public Health Sciences, Wake Forest University School of Medicine, Winston-Salem, NC