SCAELET FEVEE. 45 



Certain anatomical points are worth noting as bearing on the 

 complications of scarlet fever. 



The possibility of the buccal, nasal and pharyngeal cavities 

 acting as foci of secondary infection has already been alluded to. 



The secondary adenitis involves that group of glands which is 

 in anatomical connection with the fauces and nasopharynx. 

 Swelling of these glands sometimes immediately precedes the 

 onset of acute nephritis, and there appears to be some connection 

 between the two phenomena. 



The otitis media is due, like that which occurs in measles, to 

 extension of infection along the Eustachian tube. The remark- 

 able limitation of this complication to childhood is explained by 

 the shortness of the tubes in early years, by their nearer 

 proximity to the tonsil at this age (they open at the level of the 

 hard palate) and to the greater liability of the nasopharynx to be 

 blocked by adenoid tissue. Under these adverse circumstances 

 the cilise of the tubes fail to protect them. The parotid lymph 

 glands, which receive lymphatics from the tympanum, may 

 become swollen as the result of otitis media. 



In childhood the air spaces of the mastoid are very superficial, 

 and may actually communicate with the surface, so pus may 

 make its way outwards below the periosteum. Pus superficial to 

 the periosteum may be derived from a suppurating mastoid 

 lymph gland. 



The broncho-pneumonia of severe scarlet fever is explained by 

 the nearness of the glottic aperture to the faucial inflammation, 

 and the consequent aspiration of infective discharges from the 

 nasopharynx. 



The distribution of scarlatinal inflammation in the kidneys 

 is mainly influenced by vascular arrangements. The typical 

 nephritis is chiefly, but not exclusively, glomerular. 



The localisation of what is known as the " septic rash " appear- 

 ing in scarlet fever is largely determined by pressure ; it is found 

 on the extensor aspects of the elbows and knees, but is also seen 

 on the cheeks and buttocks. 



Irritating discharges from the nares, angles of the mouth and 



