This section is from the book "Practical Dietetics With Special Reference To Diet In Disease", by William Gilman Thompson. Also available from Amazon: Practical Dietetics with Special Reference to Diet in Disease.
The invasion of smallpox is usually abrupt, and the temperature may reach 1040 F. on the first day. There are anorexia, thirst, vomiting, and prostration, in addition to other symptoms. The fever continues for three days, or until the eruption has fully developed, after which it subsides. During the febrile stage a light fluid diet should be given, such as is recommended for fever in general - milk, broth, gruel, etc. (p. 423). The thirst is usually considerably relieved by taking cool liquids in abundance, such as water, iced lemonade, Seltzer water, etc. If there is much eruption in the throat, there may be considerable dysphagia.
During the suppurative stage of the eruption the patient requires an abundant supporting diet, and as much milk, eggs, whisky, and stimulating meat broths should be prescribed as can be digested. The patient should be fed at least once every two hours, and must be awakened three or four times at night for food. Vomiting is not to be dreaded after the onset of the disease. The combined effect of the irritation of so large a cutaneous eruption, and of the secretion of so much pus from the pustules, which may amount to many ounces, is exhausting to the last degree, and earnest effort must be made to counteract it. This is especially true of all confluent cases. A dozen eggs, three quarts of milk, and ten or twelve or more ounces of whisky or brandy is not too much to order for an adult. These materials may be given alone or in combination, as eggnog, milk punch, etc. If the stomach rebels against so much food, the rectum must be utilised for part of the work.
This supporting treatment should in all severe cases be commenced early, even in the vesicular stage of extensive eruption, without waiting for signs of exhaustion, which are otherwise certain to follow. If strong liquor is not tolerated, champagne or other wine must be substituted.
Convalescence occupies from one to four weeks, according to the severity of the attack. The diet should be slowly increased, and should comprise abundant animal food, meat, milk, and eggs, and alcoholic stimulants, such as ale, porter, or Burgundy.