LXXXVIII.—A SEARCH FOR FILTRABLE VIRUSES IN CUTANEOUS DISEASES OF UNKNOWN ETIOLOGY

Abstract

The present report deals primarily with the application of a recently developed experimental method to the etiologic problems of a group of cutaneous diseases the causes of which are unknown or in dispute. Most of the clinical material included in this study came from cases of psoriasis, pityriasis rosea and lichen planus. The experimental investigation of 7 cases of pemphigus vulgaris is the subject of a separate communication.¹ The methods of mycology and bacteriology have been extensively employed in attempts to determine the causes of the previously mentioned cutaneous diseases, but to date their origin remains obscure. It was therefore determined to reinvestigate the conditions by means of the technic of egg inoculation which was developed by Goodpasture² and his co-workers for the study of filtrable viruses and other infectious agents. This method utilizes the embryonic chick and its enveloping membranes as an experimental animal. The advantages of