Plica polonica was described as the endemic disease prevalent in the region of Polish-Lithuanian Commonwealth and the neighboring countries in the XVIth - XIXth centuries, beginning with a long lasting nervous-rheumatic ailment, progressing to formation of matted, felted and filthy hair plait. Plica polonica till the end of the XIXth century in Vilnius was believed to be multi-organ disease, involving not only skin and its appendages, but also associated with number of chronic diseases. Plica polonica was believed to cause seizures, headaches, insomnia, inflammations, temporary blindness, deafness, ulceration, and other diseases. Paradoxically, plica polonica was also thought to be a good treatment method for chronic conditions, and sometion as a treatment method to recover from the internal diseases. In 1876 Vilnius Medical Society finally declared that plica polonica was not a disease, but a result of obscurity, prejudice and lack of hygiene, and the question whether plica was a disease, has been finally closed in Vilnius. Therefore, the aim of this study is to examine descriptions of plica polonica, to assess plica polonica evolution of perception from national plague to non-existent disease in dissertations, treatises and case reports published by scholars of Vilnius University and Vilnius Medical Society in the XVIIIth-XIXth centuries in Vilnius.
