The etiology of psoriasis has been the impelling motive for much elaborate research and the occasion of many hypotheses. These hypotheses have invoked every conceivable irregularity in the human economy, including the diet, sensitization, both bacterial and fungous infection, neurotrophic, endocrine dyscrasia, anaphylaxis and heredity.
All sorts of appellations have been assigned to this disease. For instance, Schamberg1 referred to it as the "dermatologic mystery," and while he expressed a belief in familial incidence, he did not favor the theory of heredity. He assigned rheumatism, gout, defective elimination, defective assimilation of food, pancreatic disease, digestive and nutritional disorders, disturbances of the nervous system, fright, shock, neurotic conditions, tuberculosis, endocrine disturbances, parasitism and disorders of metabolism as possible causes of this mystery. Of this group of possible causes, he expressed the belief that the rheumatism is so often associated with the disorder that it must have some relation
HEDGE HM. THE BLOOD IN PSORIASISWITH SPECIAL REFERENCE TO CALCIUM, PHOSPHORUS AND POTASSIUM. Arch Derm Syphilol. 1931;24(2):204–217. doi:10.1001/archderm.1931.01450010211004