Synonyms:—Break bone fever; dandy fever; bouquet fever; three day fever.

Definition:—An acute, infectious, epidemic disorder, characterized by a double febrile paroxysm accompanied with severe aching pains in the joints and muscles, and in perhaps one-half of the cases with a cutaneous rash.

Etiology:—The specific cause of this disease has not been discovered. More recent experiments have been made to determine that it is conveyed by mosquitos, but, while evidences are strongly in favor of that theory, nothing conclusive has been arrived at. The disease occurs in hot weather and more frequently in low altitudes, and conversely is abruptly terminated by the occurrence of cold or frost and by taking the patient to a high altitude. The disease spreads in a locality with incredible rapidity, and sometimes attacks almost the entire comfnunity without regard to race, sex or social condition. The disease seldom occurs except in tropical or sub-tropical climates.

Symptomatology:—The period of incubation is short, not more than four days, and there are almost no premonitory symptoms. The attack occurs abruptly; the suddenness of the onset is characteristic. There is a chill, not necessarily severe, followed at once by fever, which may reach 106° at the end of the first day. The pain in the limbs described as bone breaking, accompanies the fever, and the headache is most excruciating. The pain is increased by any movement of the patient, and the joints become swollen, red and excruciatingly tender, resembling acute rheumatism. The patient's sufferings are indescribable. The tongue is heavily coated, there is loss of appetite, and often, though not always, severe nausea and vomiting. There is rapidly increasing prostration, with rapid respiration and pulse. The rash, which occurs in perhaps one-half of the cases, is an erythematous eruption resembling somewhat that of scarlet fever, or it may be roseolar and papular.

After two or three days of fever, there is a crisis, the temperature drops, there is profuse sweating with diuresis, diarrhea and perhaps dangerous epistaxis. The active symptoms abate or disappear temporarily and the rash fades. In a few cases, at about the end of the second day, while the temperature is at its highest point, the pulse begins to fall, and continues to fall until it is as low in some cases as 45 beats per minute. It falls to at least 70 beats before there is any apparent decline in the temperature.

While the patient is improved and is able to be up, he is not well, and after from two to four days a second attack occurs similar to the first, but seldom as severe. This may last but a few hours and not above two days. With this the rash develops again and may last for some days, disappearing finally with a mild desquamation which may be weeks in disappearing.

The complete recovery of the patient is very slow. There is soreness and pain in the muscles and joints for a long time, and in the soles of the feet. The prostration, which is not as great as that of some other infectious fevers, is not readily recovered from. The patient is restless and sleepless, and boils may develop.

Differential Diagnosis:—In many points Dengue resembles influenza or la grippe and may be mistaken for it. The absence of an eruption and the presence of the characteristic germ of influenza will decide the diagnosis and the entire absence of an eruption in acute rheumatism will distinguish it from that disease.

Scarlet fever differs in the character of the onset, the eruption, in the course, and in the absence of a relapse and of any rheumatic symptoms. It is most difficult to distinguish in hot climates at times, between this disease and yellow fever. The rapid, steady rise and sudden termination of the fever in the latter disease, with jaundice, black vomit and a hemorrhagic tendency, and no second attack will assure a diagnosis.

Prognosis:—The prognosis is good, as persons in middle life, previously healthy, seldom die of it. In the aged and in infants it predisposes to complications, notably those of the lungs or bronchi or of the nervous system, to which the patient may succumb.

Treatment:—In this disease we have many distinct indications for specific remedies. The bright, flushed face, bright eyes and restlessness, will be specifically met by gelsemium, and no remedy has accomplished more than this. Conjointly with macrotys and alternated with bryonia, almost the entire group of symptoms is met and successfully combated. Gelsemium must be given in full doses at the onset of the attack. Five drops of the specific medicine every hour for a few doses, then in a lessened dose or after a prolonged interval, will secure results. Another directly indicated remedy is the sodium salicylate. Three doses of fifteen grains each, given two hours apart, should abate the headache and bone pains most satisfactorily. These doses may be given alternately with full doses of gelsemium. A single dose of eight grains of acetanilid, or of phenacetin, may be given at the onset with good results, but the specifics will be very satisfactory in their action. Bryonia should be begun early and continued in frequent small doses through all stages of the disease, as long as the cutting pains in the joints and other of its indications are present. During convalescence the strychnin arsenate, 1/62 of a grain every two or three hours, will be of much service. Other tonics should be directed to the stomach and to food appropriation. Auxiliary measures, such as a hot bath at the time of the chill, subsequent cool sponging, cold to the head, a hot foot-bath will suggest themselves as their indications appear.

The Eclectic Practice of Medicine with especial reference to the Treatment of Disease, 1910, was written by Finley Ellingwood, M.D.