A study of the blood picture in scarlatina : with reference to its value in diagnosis

Abstract

(1) There is a definite alteration in the percentage numbers of white blood cells in scarlatina. (2) The polymorphonuclear cells are much increased at first and remain over normal in number until the fourth day when they begin to fall and rapidly decrease in number until the end of the first week. In most eases the fall carries the number of cells well below the normal figure but in others the figure reached may be at or about the lower physio¬ logical level. The lymphocytes are always few in number at first. They begin to increase as the polymorphonuclear cells decrease and are found increased from the 6th to the 8th or 10th days. The increase may be of such a degree as to cause a definite lymphocytosis but more usually the lymphocyte cells do not increase more than 10 - 15% above their normal high physiological figure while occasionally they are not more numerous than normally. The eosinophils are few in number until the 4th day. Then they begin to increase rapidly attaining a maximum on the 5th, 6th or 7th days and remaining increased until the 9th day at least. (3) The changes are most readily observed in a series of counts carried out from the 4th to the 8th days. (4) Under two years of age the series of changes are very marked, but over that age are less obvious becoming increasingly less extreme as the age increases. (5) All cases of scarlatina except the very severe (toxic and septic) cases show the same type of blood changes. 80. (6) In observation cases diagnosed in hospital as scarlatina practically every case showed the characteristic scarlatina blood changes, while with one or two exceptions the cases diagnosed as non scarlatinal did not show such changes. (7) The blood examination is of value in diagnosis of observation scarlets, for no other diseases except diphtheria, with serum rash, and possibly gonorrhoea with a drug rash, show changes resembling those of scarlatina. (8) There are exceptional cases, occasionally encountered which do not follow the usual laws in relation to blood changes in scarlatina, so that the blood examination cannot be taken as a perfectly conclusive clinical feature.