Is tuberculin skin testing reliable during anti-tumor necrosis factor-alfa therapy? A case report and review of the literature.

The increased risk to patients on anti-tumor necrosis factor-alfa therapy of developing active tuberculosis supports screening of these patients for latent tuberculosis infection. The current practice of determining the presence of latent tuberculosis infection primarily, and often entirely, depends on the use of tuberculin skin testing (TST). We report a patient with psoriasis on long-term etanercept therapy who had a negative TST result and a positive interferon-gamma release assay result. Similar cases have also been found through a review of the literature. These findings suggest that TST might be unreliable during long-term anti-tumor necrosis factor-alfa therapy. QuantiFeron-TB Gold testing may be a more appropriate primary test in patients with risk factors for false-negative TST results.

Why are there significant differences in published narrowband ultraviolet B dosimetry recommendations? The need for national standardization of phototherapy treatment.

Narrowband ultraviolet B phototherapy is an important treatment option for psoriasis and other skin diseases. When narrowband ultraviolet B phototherapy is initiated, one method involves determining the minimal erythema dose for each patient with the starting dose at 50% to 70% of the minimal erythema dose. An alternative method involves using the recommended narrowband ultraviolet B exposure dose based on a patient's Fitzpatrick skin type. When the recommended narrowband ultraviolet B exposure doses of separate publications are compared, alarming differences are found. These discrepancies not only create confusion but also suggest the risk of phototoxicity, or its opposite, namely the risk of suboptimal dosimetry. For these reasons, this article discusses possible explanations for the wide variation in dosimetry recommendations. To remedy the current situation, the authors advocate a national standard for the practice of phototherapy treatment with the guidelines of the United Kingdom as a possible model for emulation.