444 DISEASES OF THE SKIN 



Urticaria. 



{Nciile-rash.) 



This disease is an acute irritation of the skin, indicated by the 

 formation of circumspect elevations from one to one and a half inches in 

 diameter, and due to a vasomotor neurosis (angioneurosis) of the skin. 



Etiology. — This disease is comparatively rare, and except where 

 we can trace it as being due to some known external irritation, such as 

 stings of insects — leptus autumnalis — or turpentine. The real cause of 

 the majority of cases of urticaria is not understood, being due to some 

 internal irritation, the cause of which is unknown. This is classed under 

 the general head of idiopathic urticaria. In the majority of cases it 

 certainly is due to some disorder of the intestines (catarrh of the intes- 

 tines, constipation, etc.), and it is supposed that faulty assimilation 

 caused the admission into the circulation of certain toxic substances 

 which get into the circulation and are eliminated by the skin, causing 

 local irritation. Schindelka saw a mastiff bitch which was affected 

 with vaginal catarrh and condylomas of the vagina and accompanied 

 by general urticaria, and also saw the same condition in a poodle bitch, 

 during her period of heat. Urticaria may also follow rapid cooling after 

 the animal has been in a great state of excitement. It has also been seen 

 during dentition of the permanent molars. 



Clinical Symptoms and Course. — The manifestations of nettle-rash 

 generally show themselves without any previous fever or other phenom- 

 ena, such as want of appetite, depression. There appear over the entire 

 body circumspect flat hemispherical elevations, varying in size from a 

 pea to a large bean, on which the hair is ruffled and staring. When two of 

 these elevations become confluent the elevations are much larger; the 

 skin may be itchy, but this is rare. The course is rapid, frequently 

 twenty-four hours after the eruption appears the rash has entirely dis- 

 appeared, but occasionally a new crop of elevations appears or the disease 

 may take a chronic course (urticaria chronica) , but this is only in very 

 rare instances. The eruption may last for a number of days, and when it 

 disappears it leaves a peculiar pigmentation of the skin, Schindelka has 

 called this urticaria pigmentosa. 



Treatment. — In the acute cases, the condition disappears before 

 treatment can be of use. In slower cases, as a rule, saline laxatives, 

 saturated solution of sulphate of soda, Hunyadi Janos, Apenta; and when 

 there is itching use some of the local preparations recommended in 

 erythema. 



