By the older writers (Willan, Rosenstein, Fuchs) it was very dogmatically asserted that one attack of measles completely extinguished all future susceptibility to the disease. Of late years this dogma has met with much opposition, and numerous observations have been recorded which, if entirely trustworthy, would lead us to believe that rubeola may occur not only twice, but several times, in the same individual. While from analogy and actual experience we are quite sure that the recurrence of measles is not so uncommon an event as it was once held to be, a closer examination of the question in all its bearings clearly confirms us in the belief that subsequent attacks are much more infrequent than is now thought to be the case by many, and that other diseases, more or less resembling true measles, are largely responsible for errors of diagnosis in this regard. Panum found that all the old people who had measles during the epidemic on the Faroe Islands in 1781 escaped it in 1846. Both Rosenstein and Willan declared that they had never witnessed an instance of the true recurrence of measles. Among other facts, it may be stated in this connection that Woodward (loc. cit.) has shown that during our late war, while members of regiments recruited from the rural districts, who had never before had measles, largely took it when exposed to its influence, regiments from the cities, who had presumably acquired the disease in childhood, remained almost entirely exempt.19 Other arguments of a similar sort could be readily adduced. There is no question that mistakes in diagnosis have occurred from confounding rötheln, roseola, etc., which closely simulate measles, with that disease. Those particularly engaged in the treatment of cutaneous affections could multiply instances of such errors. It is quite significant that for certain analogous infectious diseases—e.g. variola and scarlatina—the same frequency of recurrence is not claimed, although as a matter of fact they do occur. The explanation would seem to lie in the fact that neither small-pox nor scarlet fever is so closely counterfeited by other skin affections, notably by rötheln, as is measles. But it would be entirely contrary to analogy and indubitable experience to go to the extreme of the older writers and absolutely deny the possibility of second, and even third, attacks of rubeola. The frequency of such cases is, however, as Henoch20 truly states, much overestimated.
19 These observations of Woodward were made without any reference to the question at issue.
20 Lectures on Diseases of Children, N.Y., 1882, p. 282.
Occupying quite a different position from the measles induced by reinfection from without are the so-called relapses of rubeola. These relapses, which may occur in from two to four weeks after the original invasion, are analogous to the similar occurrences in scarlatina and typhoid fever. I am cognizant of but a single case of this sort, but Steiner and other accurate observers record a number of such instances.
SYMPTOMS AND COURSE.—It is generally stated that the stage of incubation exhibits no symptoms whatever; but it is undoubtedly true that the patient will sometimes appear dull and listless, and, on occasion, even give evidence of some slight and ephemeral elevations of temperature. As a rule, however, this period is devoid of any marked indication of the presence of the measles poison in the system.21
21 Some writers describe a much more marked train of symptoms as prevailing at this time than seems warranted by general experience, and Rehn has gone so far as to declare that the prodromal period, as usually understood, properly commences in the stage of incubation. Bohn is inclined to a similar view. The prodromic stage of authors is, then, to be looked upon as the "period of the mucous membrane exanthem."
The prodromal stage is usually ushered in by symptoms of general malaise, fretfulness, more or less frontal headache, shiverings, nausea, loss of appetite, excited sleep, and sometimes delirium. Vomiting is not so common in measles as in scarlatina, and may occur at any time previous to the appearance of the rash. The tongue is apt to be coated, although it may remain clean; the taste is bad, and pressure over the stomach and bowels occasionally elicits considerable pain; an aching pain over the sternum is also noted. As a general thing, at this time patients are drowsy and inclined to sleep much. Meigs and Pepper found this a very constant symptom, which they state is in no way alarming unless associated with other more serious symptoms of local or general disturbance. Constipation is present in some cases, or the bowels may be relaxed or remain in their natural state.
The prodromal fever of measles follows a peculiar course. It is remarkably remittent in character, and is rarely of such intensity as to threaten life, as is often the case in scarlet fever. The temperature will rise on the first day to 102°-104° F., and the height of the fever at this time will measurably foreshadow the character of the subsequent course. On the second day of the prodromal stage the fever suffers a marked remission, or may even entirely disappear, to again rise in the evening. Smith has observed two exacerbations in the day. Again, in some instances, after the high initiatory fever, the temperature may remain normal till just before the rash comes out (Bohn). It is this peculiar behavior of the fever, together with the fact that the child may regain its usual vivacity in the fever-free intervals, which so often misleads the physician into the diagnosis of malarial poisoning.
The most pronounced feature of this stage of the disease is, beyond all others, the catarrhal affection of the mucous membranes. The mucous membranes of the eyes, nose, mouth, and air-passages are all more or less involved, and the patient suffers in varying degrees from photophobia, coryza, hoarseness, cough, and pain in swallowing. Sneezing is frequent and annoying, and slight epistaxis is not uncommon. The cough usually appears on the first day, simultaneously with the fever. It is not very troublesome at first, but by the fourth day it becomes more frequent, assuming a hoarse, barking, paroxysmal character. Expectoration is scanty, and auscultation reveals a harsh vesicular murmur or else sibilant râles. Alarming but not dangerous attacks of false croup may come on during the night. Many observers have called attention to the red spots (papules) in the oral cavity, which make their appearance during the period of invasion. According to Bohn, usually on the second or third day from the beginning of the fever there appear upon the slightly hyperæmic mucous membrane of the soft palate, palatal arch, and uvula small or large, dark, red spots that spread to the mucous membrane of the cheeks, and sometimes to the hard palate, lips, and gums. Soon they become more defined, and are to be distinguished by shape and coloring from the membrane upon which they are situated. According to the same authority, they also afford an index to the intensity and extent of the coming cutaneous eruption. It is also stated that if the latter partakes of a hemorrhagic character, the spots on the mucous membrane may also become livid. This same punctate reddening has been demonstrated in the epiglottis, larynx, and trachea (Gerhardt), and upon the bronchi and small intestines of children who had died during this stage of the eruption. It is also to be noted on the conjunctivæ. It has been assumed that this period of this disease is not to be looked upon as the stadium prodromorum, but as the period of the "exanthem of the mucous membrane." This view of the pathology of measles seems to me most reasonable; but in whatever way we may look upon the question, the practical importance of this precutaneous eruptive stage is to be insisted upon for diagnostic purposes, just as is the analogous eruption upon the mucous membrane in small-pox.
In ordinary cases of measles we do not find such profound reaction of the nervous system as in scarlatina. I believe that convulsions in the prodromal stage are much more common than available statistics would have us believe; at least, this is my own experience. Meigs and Pepper met with convulsions but five times in 314 cases at the beginning of the eruption, while Rilliet and Barthez observed but one convulsion in 167 cases. Thomas says that convulsions are almost always absent. On the other hand, Trousseau and Bohn expressly declare that they are very common, the former stating that they occur with greater frequency than in scarlatina. I consider that convulsive seizures occurring in connection with marked catarrhal affection of the mucous membranes are very important aids in forecasting a probable attack of rubeola. Fortunately, convulsions at this stage are not very serious unless repeated or injudiciously treated.