It is clear that both the frequency and the severity of the attacks are much influenced by the general state of the child’s health. Like migraine, cyclic vomiting appears to be a symptom of nervous exhaustion. It affects, for the most part, children who are intellectually alert, impressionable, and forward for their age, and who, when well, throw themselves into work or play with a great expenditure of nervous energy. Often their physical development is unsatisfactory, and we must set ourselves to correct this as the first step in prevention. It is highly important that children suffering in this way should have free opportunities for exercise in the open country, and that all the excretory organs—the skin, kidneys, and bowels—should be acting freely and efficiently. The child should live a life of ordered routine. Sleep should be sound and sufficient in amount. The diet must not exceed the strict physiological needs. Many of these children appear to have a lowered tolerance for fats of all sorts, and it may be necessary to limit strictly the consumption of milk, cream, butter, and so forth. A daily administration of a small dose of alkali by the mouth is credited with preventing attacks. In the present connection, however, we shall not do wrong to emphasise the part played by the nervous system in the production of the attacks. In all cases of cyclic vomiting it should be our endeavour to recognise and remove the elements in the daily life of the child which are proving too exhausting.
In nervous children we sometimes meet with inexplicable rises of temperature. The pyrexia may have the same periodic character as that just noted in cases of cyclic vomiting. At intervals of three, four, or five weeks there may be a rise of temperature to 103 deg. F., or even higher, which may last for two or three days before subsiding. In other cases the chart shows a slight persistent rise over many weeks or months. That in nervous children the temperature may be very considerably elevated without our being able to detect much that is amiss does not of course make it any the less necessary to be careful to exclude organic disease. Pyelitis, tuberculosis, and latent otitis media occur with nervous children as with others and must not be overlooked. If, however, organic disease can be excluded, and if the pyrexia is the only circumstance which prevents the decision that the child is well and should be treated as well, then the thermometer may be overruled and the pyrexia neglected.