The Hoesch test: bedside screening for urinary porphobilinogen in patients with suspected porphyria.

A little-known procedure for porphobilinogen screening, the Hoesch test, was examined for sensitivity, specificity, and utility as compared to the Watson-Schwartz test. The data demonstrate that its sensitivity is similar to that of the Watson-Schwartz test. The Hoesch test, however, is without false-positive reactions secondary to urobilinogen, and its simplicity makes it easier to use and more easily interpretable. We conclude that the Hoesch test should replace the Watson-Schwartz test for urine porphobilinogen screening in suspected cases of acute intermittent and variegate porphyria.