454: DISEASES OF THE SKIN 



ually becomes fainter at the edges. They become pale when pressed 

 upon, assuming a yellowish tinge ; and, when the pressure is removed, 

 the redness returns. The spots are the seat of a more or less severe pain. 

 If the irritant which has caused the erythema be speedily removed, 

 the redness and swelling disappear hi a day or two, and a slight des- 

 quamation of the epidermis finishes the process, which is always an 

 insignificant one. If the irritant be not removed ; if it be allowed to 

 operate continuously and vigorously, the erythema assumes a more 

 serious character, and new lesions form. Erythema solare becomes 

 an eczema solare ; blisters form upon burns ; in intertrigo, the epider- 

 mis is lost ; while erythema laeve may terminate in gangrene of the 

 skin. 



Spontaneous erythema, that is to say, the erythema which appears 

 without assignable cause, always attacks the dorsal surface of the 

 hands and feet, much more rarely the body or face, the backs of the 

 hands and feet always suffering at the same time. Hebra lays stress 

 upon the constancy in the situation of the disease as an important di- 

 agnostic point. The attack commences with a moderate reddening 

 and tumefaction of the regions just mentioned as its first symptom. 

 Soon nodules and lumps of a deeper red hue, and sometimes even of 

 a bluish red, appear upon the reddened and swollen basis. Hence 

 the name erythema papulatum seu tuberculosum. In some persons 

 this eruption is attended by a disagreeable sense of burning at the 

 jx>int affected ; in others there is fever. In a day or two the redness 

 and swelling about the nodules begin to subside ; a day or two later 

 the lumps themselves grow smaller and paler, and finally disappear 

 altogether. The epidermis scales off, and the entire duration of the 

 disease is from one to two weeks. Both the bluish color of the no- 

 dules, and the yellowish tinge of the skin where the nodules were sit- 

 uated, which remains for some time after the nodules have disap- 

 peared, show that, besides the exudation, erythema papulatum is also 

 attended by slight extravasations of blood into the tissue of the cutis. 

 Sometimes erythema papulatum becomes chronic, and lasts for weeks 

 and months ; it then spreads from the point first attacked to other re- 

 gions. When new nodules form upon the periphery of the first erup- 

 tion, the disease meantime having abated in its centre, it is called ery- 

 thema annulare or circinatum. If there be a red spot remaining in the 

 middle of the ring, it is called erythema iris, or mamillatum. If, as the 

 circles extend, they become confluent and broken at the point of con- 

 tact, and thus form arched lines, they constitute the so-called erythema 

 gyratum. These names recur in other eruptions, in which the disease 

 extends upon the periphery of the original seat of the eruption, having 

 subsided at the centre, that is, at the point first attacked. The various 





