198 NORMAL AND PATHOLOGICAL BLOOD 



polymorphonuclears it indicates an infection of little virulence or a 

 walled-off process with an exacerbation. It is difficult to form an opin- 

 ion when the polymorphonuclears are under 80%. Leukocytosis with 

 polymorphonuclear percentage of 85 to 90 indicates immediate opera- 

 tion; percentages over 90 point to peritonitis and if with such per- 

 centages of polymorphonuclears there is absence of leukocytosis the 

 prognosis is grave. 



Spirochaeta fevers, as relapsing fever, may give a leukocytosis of 

 from 25,000 to 50,000. 



Smallpox, especially at time of pustulation, plague, scarlet fever, 

 and liver abscess give a leukocytosis of from 12,000 to 15,000. 



Smallpox often shows a very large percentage of very characteristic large 

 mononuclears. 



FIG. 54. Leukocytosis (40,000); sixteen polymorphonuclears in field. (Cabot.} 



The leukopenia and lymphocyte increase in measles are important points in 

 differentiating it from scarlatina. 



With meningitis counts of 25,000 are not unusual, in abscess of the 

 brain the white count rarely exceeds 15,000. 



Poliomyelitis and polioencephalitis give a slight leukocytosis during 

 the febrile accession. 



Erysipelas and epidemic cerebrospinal meningitis also give a leukocytosis of 

 from 15,000 to 20,000. In malignant diseases we sometimes have a moderate 

 leukocytosis. Rogers states that in liver abscess, with a leukocytosis of 15,000 to 

 20,000, we have only about 75 to 77% of polymorphonuclears there being also 

 a moderate increase in the percentage of large mononuclears. 



Drugs such as antipyrin may give a leukocytosis. The leukocyte increase of 

 pilocarpine is rather a lymphocytosis. 



