In malarial sections there are certain well-defined diseased conditions that occur with marked regularity; in fact, the period is as well marked as in any of the intermittents, but with this difference,—there is no fever. Almost every disease may have a distinct periodic complication, and need special treatment, but the neuralgias are the ones commonly embraced under the head of masked intermittents.
The nerves most frequently involved are the supraorbital and infraorbital branches of the trigeminus. The headache is intense and persistent. Occipital pain is also quite common, while intercostal and sciatic neuralgias are of frequent occurrence. Earache may occur at a certain hour each day.
In all of these forms the pain usually begins in the morning, increases in intensity during the day till just before the close of an attack. Croup often shows a tendency to occur periodically, and my first recollection of this disease, as taught me by my father, was the giving of quinia during the afternoon following an attack. We occasionally meet with a case of diarrhea or dysentery, occurring only in the morning. In any or all of these malaria should be suspected, and antiperiodics administered in conjunction with the indicated remedy.