DIAGNOSIS 



1337 



negative to Wassermann's reaction. A modification of the Weil- 

 Felix reaction with killed Xjg is called ' Neuber's diagnosticum.' 

 It is praised by some and condemned by others. 



The differential diagnosis has to be made from pappataci fever, 

 dengue fever, relapsing fever, malaria, ' enteroidea ' fevers, rat- 

 bite fever, cerebro-spinal meningitis, pneumonia, septicsemias or 

 pyaemias, and uremia. 



From pappataci fever it can only be recognized at its commence- 

 ment by the presence of leucocytosis and the absence of leucopenia, 

 and the same holds good for dengue fever. 



From relapsing fever it may be diagnosed by a blood examination 

 showing the absence of spirochaetes and the presence of leuco- 

 cytosis, as well as by the clinical symptoms, but especially the 

 mental disturbance. 



From malaria it can only be separated by the absence of the 

 malarial parasites, which may be present in double infections, and 

 by the leucocytosis. 



From * enteroidea ' fevers it may be distinguished by the often 

 abrupt onset, by the leucocytosis, and by the absence of the 

 specific ' enteroidea ' organisms in the blood and faeces. 



From rat-bite fever it may be known by the absence of the mark 

 of a rat -bite, absence of the enlarged lymphatic glands, and of the 

 spirochaetes in the blood. 



From cerebro-spinal meningitis it may be told by the clear cerebro- 

 spinal fluid containing no meningococci, and by the absence of stiff- 

 ness of the neck, Kernig's sign, and the presence of the typical rash. 



From pneumonia it may be parted by the absence of definite 

 apical or basal dulness, of the bronchial respiration, as well as by 

 the character of the sputum, with absence of blood. 



From septiccemias and pycemias by blood cultures showing an 

 absence of pyogenic organisms, by the absence of blood destruction, 

 and by the presence of cerebral symptoms. From septiccemic 

 plague it can be distinguished by the course and blood cultures. 



From urcemia it is known by the presence of fever and by the 

 analysis of urine. 



From 'flea-bites ' the diagnosis, of course, has only to be made 

 in cases of fever, and can be done by the history, the patient often 

 stating that the rash was in existence a long time before the fever. 

 The distribution is on the limbs equally to the body. The rash is 

 composed of a number of petechial spots of a dark red colour and 

 perfectly circular in outline (see p. 1334). 



From smallpox, by absence of the fall in the temperature on the 

 fourth day, absence of shotty papules appearing on the face on 

 the fourth day; but the diagnosis in times of contemporaneous 

 epidemics may be almost impossible. When in doubt and before 

 the specific rash appears the presence of well-marked vaccination 

 marks are in favour of typhus. 



From influenza, by the absence of the catarrhal symptoms. 



From plague, by the absence of the buboes and the plague bacilli 

 therein. 



