LETTERS TO THE EDITORS
To the Editors:
Franck and Emilie Dayan’s article “Porphyrins: One Ring in the Colors of Life” (May–June) has a final section on porphyrias in plants that is both interesting and constructively provocative. But the preceding sections on human disease states display a lack of familiarity with the literature. The authors have muddied the field by including only titillating snippets, avoiding critical evaluations and omitting other documentation.
The Dayans report that King George III suffered from variegate porphyria, but the evidence favors a different disease, acute intermittent porphyria. Ida Macalpine and Richard Hunter were the first to suggest, in 1966, that the king suffered from acute intermittent porphyria, based on his well-documented physical symptoms and psychotic episodes. It was an insightful and persuasive analysis. But two years later, they modified their working hypothesis to variegate porphyria to accommodate meager evidence for an additional symptom, skin sensitivity. Specifics of the variegate porphyria hypothesis were much criticized in the subsequent literature.
Furthermore, the Dayans quote from an attending doctor’s report that King George’s urine “is of a deeper colour and leaves a pale blue ring” on the chamber pot. The blue color demands attention, given that brownish-red pigments are expected during the crises of porphyria patients. In 1996, I published an explanation in The Lancet. In that article (“King George III’s Urine and Indigo Blue”) I show that episodes of blue urine can be a metabolic consequence of severe constipation—which is indeed a hallmark of acute intermittent porphyria crises. Readers may be interested in viewing my recent presentation on these subjects, which is available online at http://ow.ly/5yUK4.
Wilfred N. Arnold
Kansas University Medical Center
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