FAVUS Favus is an affection caused by the achorion of Schonlein, in which small sulphur-yellow platelets are formed around the hair fol licles. At first yellow punctiform growths appear on the scalp around the follicles which gradually increase in size to that of the yellow plate lets, the upper surface of which is concave with a central depression while the lower is Convex. These platelets, called scutula, always grow around the hairs, at first singly, afterwards communicating; they then lose their yellowish color and the scalp looks whitish gray, dry, dust covered, and has an unpleasant odor, like the feces of mice. The skin under the scutulurn is at first slightly hyperamie, then becomes atro phic, whitish, and sinks in. The hair suffers likewise, loses its color, becomes thin and brittle, looks dusty, and falls out; the follicles and papillary bodies likewise become obliterated. The affection is chiefly situated at the head and in the hair of the head, but may spread over the entire body (often with a herpetic prodromal stage) and may even attack the finger nails which become brittle and splinter off. Favus is chiefly found in children of the poorer part of the populace in coun tries where cleanliness leaves much to be desired (Poland, Russia, IIungary). In Germany it practically only occurs when introduced from Poland; it is very rare in West and Central Germany.
Pathological scutulum is an accumulation of fungi in the corneal cells, the fungi being in the exterior root sheath of the hair. They invade the medullary space and in later stages lead to a pressure atrophy of the skin.
is caused by the penetration of the achorion of Schonlein into the skin. The transmission takes place from person to person, but may also take place through mice suffering from mouse favus, and through their intermediate agents, eats.
diagnosis of favus is easily established by the presence of the scutula and fungi. When the scutula are covered by grayish white scaly deposits, application of alcohol (Neisser) is suffic ient to re-establish their yellow coloration. (Differential diagnosis with scaly, eczema of the head.) Nor is the microscopic demonstration of the fungi in the seutula and hair at all difficult (unstained prepara tion made lighter by a 50 per cent. solution of potassium or stained preparations after Weigert).
prognosis of favus is unfavorable as soon as the fungi are situated in the hair, as it is not always possible to free the root sheaths of the hair from them or to remove the hair together with the root sheath.
Treatment.—The treatment consequently consists in removing the hair with the root sheaths, which is effected either by epilatien with the forceps, by pulling out the entire hair by means of a pitch cap under chloroform amesthesia, or by the applioation of the Rontgen ray. But as with the last-named treatment it is »ot always possible to secure the removal of the sheath, the X-ray will frequently prove in effectual. The best method is the systematic epilation with the for ceps. The operation completed, the head is bandaged with a 6 to 10 per cent. pyrogallus ointment and regularly washed with disinfectants, such as formalin or corrosive sublimate. Favus of the nails is treated with mercury plaster, hand baths, and painting with corrosive subli mate alcohol or pyrogallus acetone.