Acute porphyria amongst psychiatric patients

A total of 519 consecutive patients, admitted to psychiatric wards of two different hospitals, were screened for evidence of increased excretion of porphobilinogen in the urine by original Watson Schwartz test and modified Watson Schwartz test supported with quantitative estimation of porphobilinogen by Remington's method in search of cases of acute porphyria amongst psychiatric patients. An additional 273 normal healthy volunteers were also screened as controls. Two cases (0.38%) were found which could be unequivocally diagnosed to be suffering from acute intermittent porphyria amongst psychiatric patients. These cases belonged to the category of missed diagnosis being labelled as hysterical. Seven more cases were positive by modified Watson Schwartz test but the test was only transiently positive and the Ehrlichaldehyde reactor substance was unstable. In the absence of detailed enzymatic and family studies, these cases have been kept under the category of suspected prophyria. A significant number of psychiatric patients (12.9%) gave positive original Watson-Schwartz test but were negative for modified test. Similar reaction was seen in 2.6% of healthy controls. The significance of this finding needs to be evaluated.