524 



DISEASES OF THE SKIN. 



plants, buckwheat, green potatoes (Lippold), green rye, as also 

 abrupt changes of regimen, etc., are especially noted for producing 

 this disturbance (in the human species, in predisposed individuals 

 it appears after eating strawberries, raspberries, shrimps, oysters, 

 fish, etc.). 



It may occur in the course of other affections of the derma; thus 

 Schindelka has seen it coexisting with English variola (pustulous 

 dermatitis). 



3. An abrupt chilling of the skin at the time when the body is 

 much overheated may determine urticaria ; the disease is therefore 

 quite frequent in the spring and fall, also during great heats, stormy 

 weather, rain, violent efforts, and rapid movements. It sometimes 

 accompanies rheumatismal hemoglobinemia. In all these cases it 

 seems rather due to the retention of injurious substances in the or- 

 ganism, which has originated under the influence of cold, than to 

 an indirect irritation by this agent. But in a large number of 

 others the cause of the affection cannot be determined. 



The result of these considerations shows that urticaria represents 

 mostly a purely symptomatic exanthema ; it ought therefore to be 

 considered only as an accessory symptom of the diseases of which 

 we are now speaking. We have nevertheless thought best to 

 describe it separately, because it frequently constitutes the only 

 appreciable manifestation of a morbid complexus, and because in 

 many cases nothing indicates the existence of an internal affection. 



Urticaria is frequently observed in the horse, dog, and pig, more 

 rarely in the ox. We shall first consider it as it is manifested in 

 the first three species. 



1. Urticaria of the Horse, Dog, and Ox. 



Symptoms. In the horse it was formerly described under the 

 names of pimple, ecthyma pustules, bubonic fever (Beulenfieber) ; urti- 

 caria is characterized by the sudden appearance of pimples or 

 blotches, which often extend over almost the entire skin within a 

 few hours or in one night. At the beginning we observe tumefac- 

 tions which are flat, regular, soft, of the size of a pea, on the surface 

 of which the hair stands erect, and which are usually located on 

 both sides of the neck and shoulders, also on the back, the pectoral 

 walls, and the buttocks. As they increase in size others are devel- 

 oped ; they often become confluent, and form blotches of the size 

 of a hand or plate, which in certain cases spread to the head, to the 



