346 THE MITES 



some substance for destroying the mites is applied. Sulphur 

 ointment made by mixing one-half an ounce of sulphur to ten 

 ounces of lard, is excellent; its virtue lies in the formation of 

 hydrogen sulphide in contact with the skin, sulphur itself being 

 inert. A still more efficient though more expensive remedy is 

 a beta-naphthol ointment, prepared as follows: beta-naphthol, 

 75 grains; olive oil, 2J fluid grams; sulphur, 1 oz.; lanolin, 1 oz.; 

 green soap, 1 oz. One of these applications, or some other, is 

 unsparingly rubbed into the skin of the infected portions of the 

 body, and of a considerable area around them. When rubbed 

 in for 20 or 30 minutes the patient goes to bed, leaving the oint- 

 ment on his body until morning when it is washed off with another 

 bath. Meanwhile the soiled underwear, bedclothes or other 

 possibly infected articles are sterilized by boiling or baking. 

 Since this course of treatment does not destroy the eggs it is 

 repeated in about ten days in order to destroy any mites which 

 may have hatched in the meantime. 



For delicate-skinned individuals the treatment described above 

 is too severe and may, of itself, give rise to inflammation of the 

 skin not unlike that caused by the mites. In such case balsam 

 of Peru may be used satisfactorily instead of sulphur ointment, 

 but should be rubbed in several times at intervals of a few hours. 

 It does not cause any irritation. 



Prevention of this annoying infection consists merely in avoid- 

 ing contact with infected individuals, and of shunning public 

 towels or soiled bed linen. A single infected individual in a 

 logging or railroad camp may be a means of infecting the entire 

 camp. Means should, therefore, be taken to guard against 

 such individuals whenever possible, and to prevent the spread 

 of infection from unsuspected individuals by care as regards the 

 use of towels and bed clothes. 



Hair Follicle Mites 



The hair follicle or face mite, Demodex folliculorum (Fig. 144), 

 of the family Demodecidae, is a species which is most strikingly 

 adapted for its parasitic life. It is a wormlike creature, very 

 unmite-like in general appearance, which lives in the hair follicles 

 and sebaceous glands of various mammals. In man it occurs 

 especially on the face. 



