INFLUENZA (GRIPPE).—An epidemic, infectious disease which is caused by the influenza-bacillus. It develops rapidly with a general feeling of indisposition, headache, pains in the limbs, chilliness, nasal catarrh and cough, and with the formation of herpes (fever-sores) on the lips and face. Influenza either restricts itself to these manifestations and disappears as rapidly as it came, or it progresses and affects in a more marked degree the respiratory passages, the digestive organs, and the nervous system.
An involvement of the respiratory passages is always accompanied with marked nasal catarrh and frontal headache, and with inflammation of the mucous membranes of the eyes, mouth, pharynx, and bronchi. A tormenting cough sets in, the sputum being at first clear and viscid, later becoming purulent. The patient complains of pains in the chest and of difficulty in breathing. More or less marked fever and acceleration of the pulse are present at the same time. If the stomach and intestines are affected, there will be nausea, vomiting, spasmodic pains in the abdomen, and severe, sometimes bloody, diarrhoea. Implication of the nervous system results in pains in the head, in the small of the back, and in the limbs and joints ; conditions of excitement, delirium and insomnia may be present ; or there may be unnatural drowsiness. In some instances also the heart may be involved, this complication being manifested by palpitation, pains in the region of the heart, and cardiac weakness.
The course of influenza, which usually averages about a week, may sometimes be protracted for weeks or months, owing to the frequent super vention of other diseases. The complications most to be dreaded are pneumonia and pleurisy, and the rapid development of hidden or beginning tuberculosis. Other affections that may' occur subsequently are : inflam mations of the nerves, paralysis, spasmodic symptoms, affections of the heart, diseases of the eves or ears, chronic catarrhs of the stomach and intestine, and irritation and inflammation of the kidneys.
The prevention of this epidemic disease is scarcely possible. During the attack it is necessary that the patient remain in bed, with cold compresses (which become warm) on the chest ; the diet should be restricted, and, if possible, it should consist of milk only. In many cases it will prove bene ficial to induce perspiration by giving the patient hot tea and hot lemonade. The greatest care is necessary during convalescence, as too early rising, errors in diet, or renewed colds are very liable to further the development of the complications mentioned.
There arc a number of acute febrile affections which occur, especially during infancy and childhood, in consequence of colds, etc. These affections, which set in with chills, fever, depression, loss of appetite, headache, pains in the small of the back, and with the formation of blister-like eruptions on the lips and in the face, last one or more days, and the symptoms may be more or less pronounced. The fever soon recedes, however, usually with the appearance of perspiration, and complete recovery soon takes place. In children these affections are mostly due to digestive disturbances ; and a restricted diet and a mild laxative are usually enough to bring about relief.
INFUSIONS.—These are watery extracts of vegetable substances which are not quite soluble in water. The usual mode of preparation is to pour boiling water on the drug, and then to macerate it in a closed vessel until the water has become cool. Infusions may be prepared also by percolation with cold water, but in this case the substance should be finely divided. The strength of an infusion varies, not only with regard to the drug pre scribed, but also according to individual cases.