230 CLINICAL BACTERIOLOGY AND HEMATOLOGY 



(cardiac or renal) there is no leucocytosis. With simple non-tuber- 

 culous pleurisy the blood is usually normal, and the same holds 

 in the tuberculous cases, but here the leucocytes are occasionally 

 raised to 18,000 or more. Such cases may be distinguished from 

 pneumonia or empyema by the presence of the iodine reaction in 

 the latter and its absence in pleurisy. Empyemata are always 

 associated with a high leucocytosis, except sometimes in the 

 tuberculous forms. 



Asthma. — True asthma has a very characteristic blood condition. 

 During an attack there is a leucocytosis of moderate grade, with 

 a great increase of eosinophiles ; 10 per cent, may be taken as an 

 average, though much higher counts have been recorded. In the 

 intervals the total numbers are normal, but there is usually a 

 moderate eosinophilia, 5 to 7 per cent, or more, and I have found 

 a slight increase of mast cells (about i per cent.), which is so 

 rare a phenomenon that it may be of some diagnostic value. 

 Eosinophilia rarely occurs associated with other forms of spas- 

 modic dyspnoea, and its presence serves to diagnose asthma from 

 cardiac or renal dyspnoea — -often a matter of great importance — 

 or from dyspnoea due to pressure on the bronchi, trachea, etc. 



The sputum in asthma is usually characteristic, and contains 

 the peculiar spirals and vast numbers of eosinophile cells ; these 

 are rarely seen in cases of bronchitis, but never in any numbers 

 in other diseases. 



Bronchitis and Broncho-pneumonia. — With simple bronchitis 

 there is the usual inflammatory leucocytosis, usually about 12,000 

 to 14,000. In broncho-pneumonia the count is much higher — 

 20,000 or more. This applies to children as well as to adults. 



Endocarditis. — Not much help can be obtained from the 

 leucocytes in the diagnosis between the simple and the malignant 

 form, since in either case there may be a normal or slightly raised 

 count. But in malignant endocarditis there is usually a rapidly 

 increasing anaemia of secondary type. The true test, however, is 

 the bacteriological one ; the blood is sterile in simple endocarditis, 

 whereas organisms are usually found in ulcerative cases, though 

 more than one examination may be necessary. 



Valvular Lesions require brief mention, since their presence 

 causes alterations which might cause embarrassment in the diag- 

 nosis of other conditions if unrecognised. With mitral lesions, if 

 not fully complicated, there is a tendency for an increase in the 

 red corpuscles (due to venous stasis) which may reach 8,000,000. 



