Mention has been made in a previous section that children show a special susceptibility to malaria . They may be infected any time after birth; in fact, not a few cases have been recorded in which the symptoms were absolutely diagnosed during the first days of life. For the transference of the disease in utero and by the mother's milk see another section.
Some careful observers assert that malaria is more frequent in children than in adults, and that, at the beginning of an epidemic, the children are attacked first (Griesinger, Boudin, Schramm, Baur, Pepper, Negre, Pellereau, etc.).
Still other writers (Dwight, Chapin, Osier) affirm that children are seldom affected. This difference of opinion may be due to the circumstances that malaria in children, especially under two years, readily escapes detection; that in cities malaria has fewer victims than in the country, and that city children ordinarily pass the greater part of the day in dwellings, and are, therefore, relatively better protected. According to Bohn's wide experience, children from two to seven years of age are the most frequently attacked.
The symptoms of malaria in children, especially under two years of age, differ in many respects from those observed in adults.
This subject has been studied particularly by Bohn, to whom we owe the best work. Among the French who interested themselves were Grisolle, Jules Simon, Bossu, Galland, Benoit, Negre, and others; among the English, Thomas, Cheadle, and Kingsley. Yet the older writers did not overlook it, as is readily seen from the complete anamneses of Morton and the references in Sydenham and Torti.
All authorities agree that children show most frequently the quotidian, less frequently the tertian, and very rarely the quartan type. In tropical and subtropical regions the quotidian and sub continued remittent types are most commonly observed.
The paroxysms occur, according to Bohn, usually between midday and midnight, while in adults the other half of the day predominates. According to the same writer, the disease begins not infrequently with the general symptoms of a continued or remittent, from which, after a few days, the typical fever develops.
We will consider, first, the typical paroxysms in children under two years of age.
The cold stage is either wanting entirely or is of so short duration as to escape observation. Only rarely is it well developed. According to Jules Simon, it lasts only a few minutes-seldom a quarter of an hour. If the child is seen at this stage, the following is observed: The face is pale, somewhat cyanotic, cool; the hands and feet are likewise cool. The skin is wrinkled; the body generally shrunken; respiration and pulse are very much hastened; yawning is frequent and vomiting is not rare.
Instead of the ordinary cold stage, Bohn observed "drowsiness, stretching of the body, yawning, trembling of the extremities, and convulsive movements of the ocular muscles; the last two especially in nurslings."
The hot stage, which is the most characteristic feature, follows. The skin is hot and flushed; the child is restless, cries for the breast frequently, or is drowsy and sleeps the whole time. The sweating stage is usually only suggested by a slight moisture on the extremities or the back of the head. There is rarely profuse perspiration. The whole paroxysm usually lasts four to six hours, but it may last twelve hours and even more.
During the interval the children are often irritable, without appetite, restless, sleepless, though sometimes none of these symptoms appears.
Herpes labialis and urticaria are frequent. Boicesco and Mon corvo, and before them Bohn, observed several times the occurrence of an eruption simulating erythema nodosum. This appeared in painful hard nodules on the extremities, about the size of a silver dollar, which became red ^and swollen during the paroxysms.
Cheadle frequently observed a scarlatina like eruption, localized principally to the neck, chest, and abdomen, which he never saw in adults. Similar erythemata were seen by Handheld Jones; in one case three or four times a day an intense redness covered the whole body of the three year old child.
The spleen is usually enlarged. The contradictory observation of Ferreira provokes doubt as to whether all the cases reported by him were actually malaria . Still we must confess that there are isolated undoubted observations of cases without splenic enlargement.
Bohn found a splenic tumor in every case, and attributed a greater diagnostic importance to this symptom in children than in adults. According to him, the spleen must often be sought, posterior to the axillary line or high up on the chest wall. The enlargement is frequently associated with sensations of compression or stabbing pain, which increases in intensity during the hot stage. This, taken together with the commonly occurring bronchitic symptoms, may lead to confusion with pleurisy or pneumonia.
The splenic tumor is, as a rule, very sensitive to pressure.
After the occurrence of several paroxysms, a marked anemia sets in. With this we never fail to find a large spleen, which extends not infrequently to the umbilical region.
Among the associated symptoms, diarrhea is important. It may be extremely profuse. It usually sets in at the beginning of the paroxysm, persists throughout it, and sometimes after it. During the apyretic interval it is usually absent, or at least lessened in severity (Cantenau). The stools are either yellowish or greenish in color.
According to Bohn, the paroxysms are sometimes introduced by violent choleraic diarrhea with rapid collapse; sanguinolent stools point especially to malarial infection. The vomiting is sometimes so continuous that it threatens life; it may even persist during the intervals.