Stress and the precipitation of acute intermittent porphyria.

:UTE INTERMITTENT porphyria, following Watson's classification, is a subgroup of porphyria hepatica, which is probably inherited as a non-sex-linked Mendelian dominant. Porphyria hepatica can present in any of four ways: intermittent acute, cutania tarda, mixed or combined type, and latent. In the United States the most common form is the intermittent acute, with the prime mode of onset characterized by symptoms referable to the abdomen and central nervous system. Apparently the incidence varies greatly from one country to another. In the United States it has been estimated as 1 in 150.000. The ratio reported by Dean and Barnes,' in South Africa, is much higher at 1 in 100. Acute intermittent porphyria has been mistaken for so many diverse syndromes that, in the words of Watson, "it well deserves the sobriquet of 'little simulator'." Psychiatric symptoms are an integral part of the clinical picture of the disease. Hysteroid behavior, conversion reactions, acting out, and schizophrenic-like phenomena have been described as occurring in porphyric patients.' 9 Abdominal pain is the most frequent presenting complaint, but paralysis of extremity musculature asso