Relapsing Fever (also known as famine-fever and seven-day fever) is one of the three great species of continued fever, the two others being typhus and typhoid. It was first definitely discriminated from these diseases by Dr Henderson of Edinburgh and other Scottish physicians about 1842, but it can be traced back with certainty in the records of disease a century farther, when it was prevalent in Ireland and Scotland. During the 19th century it has been met with in those countries, in England, in central and eastern Europe, the countries surrounding the Levant, North Africa, India, China, and, though never extensively, in North America. Relapsing fever usually begins suddenly with rigors, a sense of chilliness, and frontal headache. Febrile reaction soon sets in, with a temperature of 104° or more, and pulse usually over 100 per minute; the tongue is coated with a thick moist whitish fur; and the skin is often jaundiced (a phenomenon that never occurs in typhus or typhoid fever). There is severe aching pain in the joints and muscles, and great sleeplessness; but delirium, if present at all, usually comes on only towards the end of the first week. After the above-described symptoms have lasted for a period varying from five to eight days, generally on the seventh day, a sudden change takes place. This crisis commences with a copious perspiration, which is followed by a rapid falling of the pulse and temperature to or below the normal, and the patient appears nearly well. But from the fifth to the eighth day of this seeming convalescence a sudden relapse occurs, and all the primary symptoms return; these often run a rather shorter course than before, and again terminate in sweating and in a second convalescence, which is in most cases permanent. The relapse sometimes, however, occurs three or even four times. Death is a rare termination of relapsing fever; and when it does occur, it is usually before the seventh day of the disease. No important anatomical lesion is constantly observed in the bodies of those who succumb to this disease, except enlargement of the spleen. One form of the disease, however, is much more severe, and very often fatal. It was originally described as a distinct disease under the name of bilious typhoid, and is characterised by more marked implication of the digestive organs, by the constant presence of jaundice, and by absence or incomplete development of the crisis and intermission. It has now been shown to be really identical with relapsing fever proper. Relapsing fever is generally met with among those living under unfavourable hygienic conditions; it is specially apt to attack a population suffering from insufficient nourishment (hence the name famine-fever), and is seldom met with among the upper classes, or among Europeans residing in the tropics, unless they are brought closely in contact with the sick. At the same time it is very infectious, spreading either directly from the patient to doctors, nurses, &c., or from clothes and bedding to washerwomen, who have suffered severely in some epidemics. It was shown by Obermeier of Berlin in 1873 that an organism (Spirillum, q.v.) is constantly present in the blood of those suffering from the disease, and his results have been confirmed by numerous other observers. Moreover, a similar disease has been produced in monkeys by inoculation with the organism, which has also been found in their bodies after death. There can be no doubt, therefore, that this spirillum is the cause of the disease (see GERM THEORY OF DISEASE). Though relapsing fever has been abundantly proved to be distinct from typhus, they are often associated in a curious way; epidemics of the two diseases have frequently been observed to occur in the same place either simultaneously or successively.
Treatment.—The patient, as in other febrile diseases, must be kept in bed; an emetic at the commencement of the attack is often useful, and aperients may be required; a light but liberal diet should be given. Opiates are frequently necessary to relieve the pain and sleeplessness. No means have yet been discovered for cutting short the disease or preventing relapses.