Pruritus. Itching. Hautjucken. 481 



only obvious symptom, and if local structural lesions appear, it is 

 purely the result of scratching, rubbing or tearing. 



The pruritus of the skin may, however, be a symptomatic 

 manifestation of some deeper source of irritation, as in the case 

 of the inveterate rubbing of the tail in horses suffering from 

 sclerostomata or oxyuris, or even cestrus larvae in the rectum, 

 the rubbing of the nose in dogs suffering from pentastoma, and 

 in sheep harboring cestrus larvae in the head ; the licking and 

 dragging of the anus in dogs suffering from whip- worm, uncinaria, 

 ascaris, or t^mia : or an itching of the nose in different animals 

 in connection with gastric or intestinal worms. 



Some of the conditions that give rise to urticaria may appar- 

 ently lead to the simple inveterate itching. Thus various gastro- 

 intestinal irritations create a neurosis of the skin, which is con- 

 tinuous with the intestinal mucosa and in the most intimate 

 nervous sympathy with it. The mad-itch of the western states 

 has been traced to impaction of the omasum and irritation of the 

 other stomachs. Yet the pruritus is so intense that even the 

 large ruminant rubs, scratches, and lacerates with its teeth the 

 affected parts of the skin. In dysentery cattle sometimes rub 

 the root of the tail and buttocks until the soft tissues are worn 

 to the bone (Trumbower). In both horses and cattle a chronic 

 indigestion is at times associated with universal pruritus (Haub- 

 ner) . In victims of rabies, in which lesions of the throat and 

 stomach are often pronounced, itching may be so inveterate that 

 the victim tears his body and limbs with his teeth . Disorders of the 

 liver, which inevitably entail intestinal troubles are at times a cause 

 of cutaneous pruritus. Again affections of the kidneys, with im- 

 perfect elimination of irritant waste products become an active 

 cause of itching without visible structural change. Other cases 

 might be attributed to nervous derangements as in rabies, and 

 even to disorders of sanguification. The chill in passing from a 

 hot building to cold wintry air may arouse it. The more cer- 

 tainly the affection is the result of a nervous reflex, the greater 

 its title to be considered pruritis. 



Treatment. The most important thing is to discover and re- 

 move the cause. If intestinal parasites vermicides may prove 

 successful. If impacted and congested omasum in cattle i lb. 

 31 



