406 DISEASES OF THE SKIN. 



Clinical Symptoms. Favus is found in special regions of 

 the body, namely, upon the forehead, back of the nose, abdomen, 

 and external surface of the hindlegs, as gray, gray-yellow or even 

 saffron-yellow, dry, brittle crusts or eschars. These are about the 

 size of the head of a needle in the beginning, but gradually by their 

 growth cover the entire surface, and may finally become from 2 to 

 5 mm. in thickness. They appear in the shape of round or ellip- 

 tical scutula, depressed in a saucer-like manner, generally per- 

 forated with a dull, lustreless hair, which drops out later on. If 

 the escharious mass is removed we find a corresponding depression 

 with exposed, very red epidermis. As a rule, this is followed by 

 bleeding, and, according to St. Cyr, there is always great itching. 

 This last, however, has not been the author's experience. 



Therapeutic Treatment. The treatment of this disease is 

 easy, consisting of removal of the scutula and a daily application 

 of antiparasitic agents, especially tincture of iodine, carbolic acid 

 and creosote solution, sublimate solutions of red, white, or gray 

 mercurial ointment, solution of salicylic acid (10 per cent, solution 

 with alcohol), and tar soap. Chloride of sodium (common salt) 

 has recently been advocated in the treatment of ringworm. It is 

 either to be applied in saturated solution 'or else made into an oint- 

 ment with vaseline. 



Concerning the prophylaxis, we refer you to the indications 

 which are given later in herpes. 



2. Herpes Tonsurans. Depilating herpes, herpetic ring, 

 herpetic eshcar, bare herpes. This fungus which is said to be the 

 cause of herpes, is called trichophyton tonsurans, and is found in 

 large masses lying on the upper portion of the epidermis, and espe- 

 cially in the hair and its covering. 



Trichophyton has a much more rapid growth than achorion. 

 It not only grows from one centre, as in the other form, but it may 

 make its appearance in a number of new centres scattered all over 

 the body, until finally the whole is strewn with numerous, isolated, 

 round-shaped bare spots. The parasite may be transmitted to dogs, 

 man, cattle, goats, cats, pigs, and rabbits. 



Clinical Symptoms. The eruption is marked by small, round, 

 or elongated herpes, which vary in shape and size between a lentil 

 and a large bean. The spots are hairless and distinctly circum- 

 scribed ; the blotches are arranged at intervals, and are generally 



