THE PURPURA AFFECTIONS These are a series of disease pictures which have the one point in common that, in the shape of an independent disease, transitory and spontaneous haemorrhages occur in internal and external parts; a tran sitory hemorrhagic diathesis.
For a long time various forms of purpura have been distinguished; the recognition, however, has gradually gained ground that they all present the same pathological picture, differing merely in degree and localization: hagnorrhages of purpura simplex merely on the external skin; of purpura rheuniatica, skin hemorrhages with simultaneous involvement of the articulations; of purpura abdominalis, skin hasmor Hinges with severe gastric and intestinal manifestations, perhaps also articular affections; of purpura fulminans, the gravest form of skin haemorrhages; of purpura htemorrhagica, or morbus maculosis Werlhoffii, skin hemorrhages combined with of the mucous mem branes or into internal organs. All these forms cannot be strictly separated, clinically, etiologically or anatomically. One form may co exist with another or change into it. From this point of view the divisions used in the following pages should be understood.
Occurrence.—Purpura is rather a rare disease, principally affecting children after the third year; infants are almost entirely spared. For ster observed an average, of 1 case in every 1300 out-patients. Girls seem to be somewhat more predisposed to it than boys; there are more cases in winter than in summer. According to C. Koch's statements concerning the frequency of purpura in St. Petersburg, the influence of some local tendency may be supposed to be at work.
certain factors must certainly be considered as indirect causes, such as weak constitution, chronic anamia, chronic intestinal catarrh, unhealthy dwellings, malnutrition especially by starch and preserved food, a direct cause cannot be stated at the present time. With great probability and in some cases with certainty it may be assumed that infectious processes are present. The attempts, how ever, to point to a specific causative factor have so far been doomed to failure and will probably so continue, it having been found that bac teria of different types may under certain circumstances produce hremor rhagic affections. Successful experiments have been made to obtain
pure cultures of various bacteria from both the maculae and the blood of purpura patients and to reproduce hiemorrhagic diseases therewith in animals, for instance streptococci (Hochheimer), staphylococci ("staph. cereus albus" Fiorentini), eolon-like rods (Benedetti), bacillus pyo cyaneus (Neumann, Hecker), bacillus purpurre (Letzerich, Gimard, Kolb, Babes), capsule diplococci (von Dungern), and a bacillus resembling that of mouse septieremia (Finkelstein). Anything specific however can probably not be attributed to any of these bacteria. Typical purpura has been observed in the course of, and following leukirniia, diphtheria, and especially of angina lacunaris (Bruck). The opinion held by Giroux and Cattaneo that purpura is not an independent disease but a symp tom-complex, continues to gain ground, and it is quite possible that such symptom-complex may also be produced by non-bacterial causes such as chills, alcoholism, overexertion, although even in these cares latent infection cannot be excluded.
The manner of the occurrence of these luemorrhages is equally ob scure. In cases where bacterial embolisms are present—and these form the majority we must not content ourselves with the assumption of a toxic influence upon the capillary walls which favors a diapedesis of the red blood. Diminished coagulability of the fibrin which had formerly been supposed to exist, cannot be demonstrated either chemically or microscopically.
the anatomical yield is small. In grave cases of purpura htemorrhagica there are parenchymatous degenerations of heart and liver, also hypoplasia of the bone marrow (Muir).
In milder cases the blood shows a diminution of the Nvhi t e and red blood corpuscles, of the htemoglobin and of the specific grav ity; in grave eases (purpura h ceniorrh a gica) considerable leu cocytosis, poikilocy tosis and micrObiasts.