Urinary pyrrole, also known as the mauve factor (malvaria), pyrroluria and krypto-pyrrole, was first described in the 1950s. It was found in the urine of patients undergoing experimental LSD treatments. When reacted with Ehrlich's reagent (p-dimethylamino benzaldehyde), several of the urines developed a purple or "mauve" color. This colored compound was first thought to be an indole. In 1961, a study using paper chromatography identified a group of Ehrlich-positive substances in the urine of patients with mental illnesses and showed that these compounds were more associated with pyrroles than indoles.2

Hotter and Mahon, in studies conducted during this same period, confirmed the presence of Ehrlich-posirive substances in the urine of patients with schizophrenia. They suggested malvaria as the name for this condition.' Other workers also confirmed the presence of Ehrlich positive substances in urine.