A system of practical medicine. By American authors. Vol. 2

by Unknown

In the present light of pathological science it is impossible to answer this question in the affirmative without considerable qualification. It must be confessed that we do not possess a knowledge of any definite chain of morbid processes constituting a distinct disease that may be designated as purpura. And yet we are able to recognize a set of symptoms varying greatly in intensity, from the most trivial petechial eruption to profuse and fatal hemorrhages, accompanied by a train of manifestations which we are unable to connect with any of the causes already spoken of, and which, indeed, depend upon no fixed exciting cause with which we are acquainted. It may be eventually proven that purpura, even as we understand it, is merely a set of phenomena due to widely-differing influences acting upon the blood and blood-vessels, and that the term will disappear from our nomenclature as indicating a disease, but will be preserved as denoting a symptom. For the present, purpura is understood to be a group of symptoms characterized by the effusion of blood into the tissues of the body, or upon its free surfaces, or into its serous cavities, which seem to arise spontaneously, and for which we are unable to assign a definite cause. With this view of the nature of purpura it becomes necessary to exclude from present consideration blood-extravasations from internal or external violence, the action of the specific principles of contagious or infectious fevers, the dyscrasia of scurvy, the influence of poisonous substances, and, in a word, any of those affections of which the escape of blood from the vessels constitutes an epi-phenomenon.

Purpura may be conveniently considered as presenting three varieties: 1, purpura simplex; 2, purpura hæmorrhagica; 3, purpura rheumatica.

These three forms of the disease are not distinguished by sharply-outlined differences, but merge the one into the other, now one, now another set of symptoms predominating. To these may be added, likewise for convenience, three sub-varieties—purpura urticans, purpura papulosa, and purpura nervosa. The difference between these forms of purpura should not be considered as of more than clinical import. Whatever variations present themselves may with probable propriety be ascribed to complicating influences.

PURPURA SIMPLEX.—This is the mildest form of purpura, and may in many cases readily escape observation. It may begin abruptly, in the midst of health, without the slightest subjective symptom, or the extravasations may be preceded for several days by some discomfort, aching of limbs, sluggishness, anorexia, even a small amount of fever. The eruption usually appears first upon the lower extremities, preferably the flexor surfaces of the thighs (Duhring), but frequently upon the legs. It extends from these points to the upper extremities and trunk, usually sparing the face. The lesions vary in size from that of a pin-head to that of a fingernail (petechiæ), or they may be linear (vibices). They remain discrete, and do not increase in size throughout their course. Each spot of hemorrhage will endure for from one to two weeks. At first the lesions are of a livid red color, and declare their extra-vascular nature by remaining unaltered when subjected to pressure. The color of these spots changes, as in ordinary ecchymosis, in consequence of the metamorphoses of the hæmatin preparatory to its final absorption, from crimson to purple, to blue, to green, to yellow, and finally fades away. When recent, the spots appear sharply outlined, with sometimes a faint encircling zone of hyperæmia, but as they become older their margins grow indistinct. While the early lesions slowly disappear, others continue to develop, and the affection may thus be protracted for weeks. At times the petechiæ appear in crops, recurring every few days, the patient at one time apparently nearly well, at another time worse than ever. Finally, the symptoms definitely disappear, to return no more, or they pass into those of other forms of purpura. During the course of purpura simplex the blood-vessels of the skin alone are affected, the deeper tissues and mucous membranes probably remaining unchanged.

Throughout the attack the general health may—usually does—remain good. As an occasional symptom there will be observed a few vesicles or blebs, containing blood, upon the skin. The extent of the general eruption may vary from a few scattered petechiæ to a copious and startling number of purpuric spots. The maintenance of the upright position tends to perpetuate the evolution of the lesions.

In elderly persons purpura simplex is sometimes observed, and has been described by many writers as purpura senilis. Hillier, following Bateman, describes it as occurring in old women "upon the outside of the forearms in successive dark, purple blotches of an irregular form and various magnitude."¹ Aged men as well as women are liable to the affection, which may quite as well appear upon the lower extremities of either sex. It is altogether likely, however, that in such cases degenerations of the vascular walls alone may cause the extravasations.

¹ Reynolds's System of Medicine, vol. i. p. 792.

PURPURA HÆMORRHAGICA (MORBUS MACULOSUS WERLHOFII).—In this form of purpura there are added to the symptoms of purpura simplex hemorrhages into and from the various mucous tracts, the nasal, faucial, pharyngeal, gastric, intestinal, renal, uterine, rarely the pulmonary mucous membranes, and exceptionally into the various serous membranes and cavities. It may begin abruptly, in the midst of apparently vigorous health, or after premonitory symptoms extending over several days, vague sensations of discomfort—headache, pains, anorexia, indisposition to exertion, and the like—or it may occur as a transition from other forms of purpura. Usually there is no fever.

The hemorrhagic spots upon the skin appear much as in purpura simplex, though the lesions are larger, acquiring the size of coins or even of the palm of the hand. Spots soon appear upon the visible mucous membranes, and free hemorrhages occur; indeed, the latter may be the first symptom observed. Epistaxis is of most common occurrence, but bleeding from the mouth, stomach, and intestines almost as frequently results. The gums are almost constantly affected, and upon inspection these may be found covered with blackish scabs, upon removal of which the mucous membrane will be found pale and not swollen—an important point in diagnosticating this affection from scurvy. Vesicles and blebs filled with blood form both on the skin and mucous membranes. They quickly rupture and discharge their contents. Bleeding from the stomach and intestines is revealed—in the former case by the vomiting of a brownish material resembling coffee-grounds; in the latter case by the passage of black, tar-like evacuations. Pulmonary hemorrhage is to be distinguished from hæmatemesis by the frothy and arterial character of the blood. Hæmaturia may proceed from any part of the urinary tract. Bleeding from several parts may occur at the same time, and may be very copious.

In the mucous membranes extravasations of greater or less extent may occur, as in the derma. Into the serous membranes they may take place with or without effusion into serous cavities. It is only, however, in cases that will almost certainly end fatally that the effusions into these cavities are encountered. Hemorrhages into the substance of the lungs, into the brain and other viscera, as well as into the tissues generally, are occasionally observed.