Plica began after an attack of acute fever, with pains like those of acute rheumatism in the head and extremities, and possibly vertigo, tinnitus aurium, ophthalmia, or coryza. Sometimes a kind of redness was observed on the thighs, and there was an alteration of the nails, which became black and rough, and again, there was clammy sweat. When the scalp was affected the head was sore to the touch and excessively itchy. A clammy and agglutinating sweat then occurred over the cranium, the hair became unctuous, stuck together, and appeared distended with an adhesive matter of reddish-brown color, believed by many observers to be sanguineous. The hair was so acutely sensitive that the slightest touch occasioned severe pain at the roots. Aviscid matter of a very offensive smell, like that of spoiled vinegar, or according to Rayer like that of mice or garlic, exuded from the whole surface of each affected hair. This matter glued the hairs together, at first from their exit at the skin, and then along the entire length; it appeared to be secreted from the whole surface of the scalp and afterward dried into an incrustation. If there was no exudation the disease was called plica sicca. The hair was matted and stuck together in a variety of ways, so as to resemble ropes (plica multiformis). Sometimes these masses united together and formed one single thick club like the tail of a horse (plica caudiformis). Again, and particularly in females, the hair would become matted and glued together into one uniform intricate mass of various magnitudes.
The hair of the whole body was likely to be attacked with this disease. Kalschmidt of Jena possessed the pubes of a woman dead of plica, the hair of which was of such length that it must have easily gone around the body. There was formerly a superstition that it was dangerous to cut the hair until the discharge diminished. Lafontaine, Schlegel, and Hartman all assure us that the section of the affected masses before this time has been known to be followed by amaurosis, convulsions, apoplexy, epilepsy, and even death. Alarmed or taught by such occurrences, the common people often went about all their lives with the plica gradually dropping off. Formerly there was much theorizing and discussion regarding the etiology and pathology of plica, but since this mysterious affection has been proved to be nothing more than the product of neglect, and the matting due to the inflammatory exudation, excited by innumerable pediculi, agglutinating the hair together, the term is now scarcely mentioned in dermatologic works. Crocker speaks of a rare form which he entitles neuropathic plica, and cites two cases, one reported by Le Page whose specimen is in the Royal College of Surgeons Museum; and the other was in a Hindoo described by Pestonji. Both occurred in young women, and in both it came on after washing the hair in warm water, one in a few minutes, and the other in a few hours. The hair was drawn up into a hard tangled lump, impossible to unravel, limited to the right side in Le Page's patient, who had very long hair, and in Pestonji's case to the back of the head, where on each side was an elongated mass, very hard and firm, like a rope and about the size of the fist. There was no reason to believe that it was ascribable to imposture; the Hindoo woman cut the lumps off herself and threw them away. Le Page found the most contracted hairs flattened.
Stellwagon reports a case of plica in a woman. It occupied a dollar-sized area above the nape of the neck, and in twelve years reached the length of 12 feet. There was no history of its manner of onset.