The occurrence of two attacks of measles in the same person is rare. In most instances there was a mistaken diagnosis, especially if the first infection should run a milder course than the second, but the occurrence of a second infection is not by any means to be denied. German measles, scarlet fever, infective erythema and other toxic erythemata (those following the use of serum and such as are of intestinal origin) can likewise give rise to error in diagnosis. The outbreak in an acute form, of a fresh rash with associated catarrhal symptoms occurs before the measles eruption. It occurs less frequently in the above-mentioned conditions.
Symptoms.—From the day of infection to the outbreak of the rash is thirteen to fourteen days. The first signs of trouble are seen usually on the tenth or eleventh day of incubation. I observed on the sixth day before the outbreak of the rash, in a ease of measles complicated with scarlet fever, a slight rise of temperature and abundant Koplik's spots on the mucosa of the mouth. A long initial or prodromal period of measles is sometimes found in sick and weakly children. This period, during which the disease reaches its full devel opment, that is, from the onset of the symptoms to the out break of the rash, usually re quires three or four clays, and is marked by the following symptoms. At first there ap pear signs of catarrh of the upper respiratory tract and eyes and the child begins to sneeze. This sneezing may soon pass off, but often con tinues throughout the whole initial period. Epistaxis may occur with the hyper emia of the nasal mucosa, or the irri tation may come on quietly, and find expression in a se vere coryza. The nasal secretion is at first serous or mucous, and it can also assume a purulent character. Severe catarrhal changes in the mucous membrane of the eyes are associated with the coryza and are shown by lachryination, photophobia, and injection of the conjunctiva., the eyelids also show marked swelling, and adhere together in the morning on account of a mucopurulent discharge. The separation of the lids is painful as the dried discharges adhere to the edges of the lids and produce irritation. The signs disappear usually with those in the nose. An important part of the catarrhal symptoms are found in the throat and bronchi.
The first definite sign of the approaching rash is a hyperremia of the mucous membrane of the mouth. This is characterized by the
presence of Koplik's spots. The credit is due to Koplik, an American physician, of haying drawn attention to this symptom which had been referred to in literature, hut little studied until now. Three or four clays, in rare cases somewhat longer, before the appearance of the_rash there appears on the mucous membrane of the cheeks small bluish white, or yellowish white points, the size of a small pin head. They are usually surrounded by a small zone of reddened mucosa, which has the appearance of a general reddening with the fine white points upon it.
This hypermemia of the mucous membrane may be wanting. The white points are mostly on the level with the mucous membrane, and are less noticeable beside the strongly shining mucosa. They may be mistaken for milk particles or fungi. The white spots which are composed of epithelium, detritus and teria of the mouth adhere rather firmly to the mucosa and on removal expose an excoriated, even gangrenous appearance, instead of a smooth glistening m ucous membrane. These are cially numerous on the cous membrane of the cheeks and on the reflection on the gums, and less frequently on the inner surface of the lips. Puncti form haemorrhages sometimes occur as the Koplik hypenemia becomes less, and ulceration of the mucosa of the cheek is found as a result of maceration. The Koplik efflorescence usually begins to fade when the rash has reached its full development. These form a very frequent group of signs associated with the onset of measles, yet they are often wanting in the milder cases, especially in those occurring in the first year of life.
As a rule there is a characteristic measles rash on the mucous membrane of the mouth. It comes on suddenly, lasts but a short time, and shows itself usually somewhat later than the Koplik spots, situ ated principally upon the soft and hard palate, with greater intensity also on other parts of the cavity of the mouth. It occurs in the forum of pale or light red irregularly outlined streaks or spots between which the mucous follicles rise. These are swollen to the size of a cherry stone, and can be seen with greater distinctness on account of the pale color of the mucous membrane of the palate.