The beneficial effects observed as a consequence of inflammation set up in the patch has led to the employment of special irritants with the express view of producing this result. Mr. Alder Smith, who has devoted much attention to this method of treatment, states that very long-standing cases can sometimes be cured by this means. He selects a small patch and ap plies to it croton-oil iu moderate quantity with a small stiff camel's-hair brush. After a few hours be applies a poultice and keeps it on the head all night. If severe inflammation has not ensued by the next day the process is repeated, and sometimes three or four applications may be needed. The object is to set up artificial " kerion," i.e., to produce a swollen, boggy, surface from inflammatory swelling and effusion in the tissues around the follicles. When kerion is produced no more croton-oil need be applied, but the part must be frequently fomented with warm water. After a few days the stumpy hairs become loose and fall out, and when the inflammation has subsided a smooth, shining, slightly-raised red surface is left " utterly destitute of all hairs and stumps and practically well." Eventually, the spot becomes again covered by new healthy hairs.
This plan of treatment is only admissible in the older children, and the application should be confined to a limited surface if the patch is a large one. While in progress the carbolic glycerine or oleate should still be applied to other parts of the scalp. By this means Mr. Alder Smith states that he has had successful results in apparently incurable cases, and has never seen any internal irritation or erysipelas set up by the use of this powerful irritant.
In obstinate cases of ringworm of the scalp constitutional treatment is also required. Often the patients are anmmic, scrofulous, or ill-nourished subjects, and cod-liver oil and tonics will be of service in improving their general health.
Ringworm of the body (tinea circinata) is quickly cured by the applica tion of a strong irritant. I am in the habit of painting the ring lightly with glacial acetic acid. This application causes some smarting for a short time, but usually cures the disorder at once. Sometimes a second appli cation to parts of the ring is required after five or six days. Other appli cations which may be used are the strong tincture of iodine, and a solu tion of nitrate of silver ( 3 j. to the ounce).