ACUTE INFLAMMATION OF THE SKIN. 453 



CHAPTER III. 



FIIE SLIGHTER FORM OP ACUTE INFLAMMATION OF THE SKIN WITH- 

 OUT VESICATION EEYTHEMATOUS DERMATITIS ERYTHEMA. 



ETIOLOGY. In this form of dermatitis, the papillary layer of the 

 skin, and, in most cases, the tissue of the cutis, becomes the seat of 

 hyperaemia and of serous infiltration. Since the epidermis usually 

 scales off after the erythema has subsided, it is to be presumed that 

 the attachment of the cuticle to the papillary layer has been loosened 

 by a simultaneous effusion upon the surface of the cutis. This effu- 

 sion, however, is insufficient in quantity to raise the epidermis into 

 blisters. Heat, the direct rays of the sun, mechanical and chemical 

 irritation, and other exciting causes to which we already have alluded 

 in speaking of hyperaemia of the skin, when allowed to act with great- 

 er intensity and for a longer time, give rise to erythematous inflam- 

 mation. Special names have been given to some forms of erythema 

 from mechanical irritation. Where it arises from the friction of two 

 opposing surfaces, it is called erythema intertrigo. This is very com- 

 mon among infants, especially among feeble ones, appearing in the 

 folds of the skin, upon the genitals, behind the ears, and in the neck. 

 It also occurs underneath the pendulous breasts of very corpulent fe- 

 males. When it arises between the nates, from their continuous fric- 

 tion upon one another during a long march, it is popularly called " a 

 wolf" ("Wolf"). The erythema which appears in cases of protract- 

 ed illness, caused by the pressure of the bed upon the sacrum, tro- 

 chanters, and other prominent parts of the body, is called decubilus. 

 That which is induced by tension of the skin in cases of severe dropsy, 

 or by trifling wounds, takes the name of 'erythema Iceve. Where there 

 long has been a discharge from the nose, and in blenorrhcea of the 

 conjunctiva, the acrid secretion which constantly bathes the skin often 

 gives rise to a superficial erythema of the upper lip and nose. Ery- 

 thema of the prepuce, scrotum, and inner surfaces of the thighs also 

 results from the continual moisture of the skin in cases of incontinence 

 of urine. 



Besides these forms of erythema, which are the result of local irri- 

 tation, there is another variety, the symptoms and course of which are 

 peculiar, and the cause of which is unknown. In this country it some- 

 times appears sporadically, but not often, but shows a great tendency 

 to periodic relapses. In other places (Constantinople, Paris), it has 

 been observed to extend epidemically. 



SYMPTOMS AND COURSE. Erythema, arising from local irritation, is 

 characterized by red, slightly-prominent patches, the color of which grad- 



