Erythema from Irritants. 473 



In addition to the food, clear sunshine is essential and an 

 individual idiosyncrasy. All animals, though equally exposed 

 are not equally attacked. 



Smptoms. These ' do not differ materially from those of the 

 white face and foot disease already described. There are in- 

 tense redness and tumefaction of the white skin or the white 

 portions, showing prominently in the delicate parts (ears, eye- 

 lids, lips), with violent itching, rubbing and sometimes vesicles 

 with yellowish contents, followed by sores and scabs. In the 

 winter season there may be itching and rubbing only. In 

 summer it may become erysipelatoid and extend to the mucosae, 

 of the respiratory and digestive organs, with hyperthermia, ner- 

 vous excitement, vertigo, turning in a circle and even spasms 

 and convulsions. 



Treatment. This is essentially the same as for the white face 

 and foot disease with this additional that the buckwheat or other 

 offensive ingredient must be withdrawn from the ration, and 

 what remains in the bowels must be expelled by saline or other 

 laxative. Cooling diuretics must follow to eliminate irritant 

 matters that may have been absorbed. 



ERYTHEMA FROM IRRITANTS. 



Irritant agents of all kinds, even if caustic or pustulant in con- 

 centrated forms, may be so diluted as to cause simple erythema. 

 Among chemical agents we have ammonia, lye, caustic acids and 

 salts, iodine, carbolic acid, and various tar products, kerosene, 

 aniline, chloroform, ether, formaline, etc. Of thermic irritants 

 may be named solar heat, fire heat, steam, hot water, hot air, 

 and congealation (chillblains, freezing) the latter being especially 

 common in the digital region when salt has been applied to snow 

 or ice. Vegetable irritants include mustard, capsicum, moulds, 

 euphorbium, rhus, milkwort, the volatile oils, etc. Among ani- 

 mal irritants must be named cantharides, mylabris, potato beetle, 

 insect stings, venom of the irritated toad, liquid discharges from 

 the kidneys or bowels, and discharges from open sores. Even 

 the escape of tears upon the face will cause erythema. 



