DIAGNOSIS. 285 



convalescence is not established, are those of the formation 

 of abscesses in various glands, and the infiltration of connective- 

 tissue and parenchymatous organs, with pus and purulent 

 matter, not unfrequently resulting in extensive tissue -change, 

 gangrene, and pysemia. These undesirable and fatal ter- 

 minations may not with any certainty be predicted at the 

 outset of the disease, seeing t,hat cases which may at the first 

 appearance of symptoms promise to terminate favourably, are 

 found at last to develoj^ the most intractable results, while 

 others which begin unfavourably occasionally prove more 

 responsive to treatment. 



Diagnosis. — Although distinctive enough in the great features 

 of its development, purpura may yet be confounded with such 

 diseases as scarlatina or erysipelas. From scarlatina it is dis- 

 tinguished — 1. By the character of the cutaneous swellings ; 

 2. By the nature of the blood-markings on the mucous mem- 

 branes ; 3. By the existence or not of angina. 



In purpura the SAvellings, whether circumscribed or ex- 

 tensively distributed as over a whole limb, are always 

 marked by the considerable elevation of these above the 

 surrounding skin, and by the suddenness and the abrupt 

 manner of their termination ; they stop as if checked by a 

 ligature. 



In scarlatina there is little or no elevation, only a raising of 

 the hair with a slight oozing and hardening from coagulation 

 of the exuded fluid; and these conditions merge gradually into 

 the surrounding tissues. In purpura the petechise or blood- 

 spots on the mucous membranes, if not at the first much, 

 larger than in scarlatina, rapidly become so by coalescing; 

 they are of a darker colour, and from the membrane on which 

 they are situated a sero-sanguineous fluid, more bloody than in 

 scarlatina, is found trickling, while it is not at all uncommon 

 to find that in purpura these petechise take on disintegrative 

 changes, the superficial membrane becoming removed and an 

 ulcerous discharging sore remaining. This condition of cir- 

 cumscribed molecular death and ulcer-formation does not as a 

 rule take place in cases of scarlatina. 



Again, angina is usually a characteristic symptom of scarla- 

 tina, and is accompanied with swollen cervical glands and 

 cough. Sore throat and cousch, althous^h met with in indi- 



