DIPHTHERIA. 361 



THE PHARYNX. 



Simple catarrhal inflammation of the pharynx, or simple an- 

 gina, is due to exposure to cold, or occurs in the course of 

 acute infectious fevers. A more chronic inflammation may 

 result from the excessive use of the voice, or be secondary to 

 some disease of the nasal cavities. The mucous membrane is 

 red and swollen. In some cases vesicles form, which burst 

 and leave behind small superficial erosions. Not infrequently 

 there are granulation-like projections above the surface of the 

 mucous membrane, due to hypertrophy, or distention of the 

 mucous glands, or to hyperpfasia of the lymphatic follicles. 



At first the mucous membrane is thickened, but later it 

 often becomes atrophic. 



Pseudomembranous pharyngitis is in most instances produced 

 by the Klebs-Loffler bacillus diphtherise. Lesions in every 

 other way similar are sometimes produced by other micro- 

 organisms, notably the streptococcus pyogenes. Such " diph- 

 theritic" pseudomembranes are especially frequent in scar- 

 latina and other acute infectious diseases, and may also follow 

 the application of various irritants to the mucous membrane. 



Diphtheria is an acute infectious disease characterized by a 

 severe toxaemia, giving rise to an irregular fever, great pros- 

 tration, often followed by cardiac and other localized or gene- 

 ral paralyses ; and locally by the formation of a pseudomem- 

 brane at the point of lodgment of the diphtheria bacilli, either 

 on an abraded surface or a mucous membrane, generally that 

 of the pharynx and upper air-passages. 



The pseudomembrane is grayish-white, later yellowish- 

 white in color. Small patches appear on the posterior pharyn- 

 geal wall, the tonsils, soft palate, or nares, which tend rapidly 

 to extend and coalesce, and thus may cover the whole pharynx ; 

 less frequently on the buccal walls, the oesophagus, stomach, 

 vagina, uterus, and on surface abrasions. The pseudomem- 

 brane is more or less adherent, and if removed a raw 7 bleeding 

 surface may be left behind. The formation of this membrane 

 is the result of the severe inflammatory process set up by the 

 diphtheria bacilli. The serous exudate coagulates and entangles 

 the other inflammatory products. Microscopically it is found 



