Pediculosis pubis is a condition due to the presence of the pediculus pubis, or crab-louse. It is characterized by more or less itching about the genitalia, together with papules, excoriations, and other inflammatory lesions. The amount of irritation varies; it may be slight, or, on the other hand, severe. The parasite, which is the smallest of the three varieties, may be discovered upon close examination seated near the roots of the hairs, clutching the hair, with its head downward and buried in the follicle. The ova may be seen attached to the hair-shafts. It infests adults chiefly, being in many instances probably contracted through sexual intercourse. #Is the pediculus pubis found upon any other part of the body?# Yes. Although its favorite habitat is the region of the pubes, it may, in exceptional instances, also infest the axillae, the sternal region of the male, the beard, eyebrows, and even the eyelashes. #State the diagnostic characters of pediculosis pubis.# The region involved, itching, variable amount of irritation, and, above all, the presence of the pediculi and their ova. [Illustration: Fig. 82. Pediculus Pubis x 25. (_After Duhring._) Female. Dorsal surface.] #Name several applications prescribed for pediculosis pubis.# A lotion of corrosive sublimate, one to four grains to the ounce; infusion of tobacco; a ten to twenty per cent. ointment of oleate of mercury; ammoniated mercury ointment, and a five to ten per cent. [beta]-naphthol ointment. Repeated washings with vinegar or dilute acetic acid, or with alkaline lotions, will free the hairs of the ova. #Cysticercus Cellulosae.# #Describe the cutaneous disturbance produced by the cysticercus cellulosae.# The presence of cysticerci in the skin and subcutaneous tissue gives rise to pea to hazelnut-sized, rounded, firm, movable tumors which, when developed, may remain unchanged for months. The parasites are disclosed by microscopic examination. Most of the cases have been observed in Germany. #Filaria Medinensis.# (_Synonym:_ Guinea-worm.) #State the character of the lesions produced by the filaria medinensis.# The young microscopic worm penetrates the skin or deeper tissue, where it grows gradually, finally reaching several inches or more in length and about a half-line in thickness; inflammation is excited and a tumor-like swelling makes its appearance, which, sooner or later, breaks, disclosing the worm. It may also present a cord-like appearance. It is rarely met with outside of tropical countries. Treatment consists in gradual extraction, or in the injection of a corrosive sublimate solution (1:1000) into the forming tumor. Asafetida internally has been found to be curative, the parasite being destroyed and subsequently absorbed or discharged. #Ixodes.# (_Synonym:_ Wood-tick.)