In most cases of influenza the symptoms arising in the digestive apparatus are but slight and limited to transitory anorexia during the febrile stage. But gastro intestinal forms occasionally occur, and in them the symptoms due to the gastro intestinal tract predominate, chest symptoms are absent, and the nervous symptoms, such as the headache, do not amount to more than the general " cephalsea gastrica." In these cases the tongue, which in influenza is usually moist and only slightly coated, is thickly coated with a dirty white layer; vomiting-frequently an initial symptom-becomes constant, and may be of a bilious character. The breath is offensive; the appetite is entirely lost; the epigastrium is tender to pressure (the frequently noted "influenzal hyperesthesia of the stomach"). Cardial gia may be present. Instead of the usual constipation, there is diarrhea, with abdominal pain, and often distention of the abdomen. Some French authors assert that these purely gastro intestinal forms are characterized by but slight fever and an especially protracted course.
In simple uncomplicated influenza the tongue is never dry or "typhoid"; almost invariably it is moist and broad. As a rule, it is but slightly coated, and is often bright red at the tip and edges.
Under the name "characteristic influenza tongue" J. Terry and others have described very various conditions. There is nothing characteristic about the tongue in influenza, as in enteric fever or scarlatina. A uniform intense reddening of the entire tongue, called glossitis, is. noted by several observers. The most detailed description is given by Bristowe, who even gives statistics in regard to it. He found the tongue "normal" in 11 per cent.; "pale and flabby" in 44 per cent.; "furred" in 41 per cent.; "red and dry" in 4 per cent., of his cases.
The mucous membrane of the mouth is often reddened; that of the palate and of the pharynx, occasionally in patches, as has been noted by Warn, Linden, Forssberg, and ourselves. Some of the older authors (Tigri, Haesser) have also noted the condition. Cases of stomatitis simplex, vesiculosa, and even ulcerosa have also been described.
Reddening and swelling of the tonsils, including the pharynx, have been frequently observed. Lacunar, phlegmonous, croupous, or diphtheric tonsillitis is always due to a mixed infection.
"Tonsillitis" or "angina erythematosa" was found by Stintzing in 60 per cent.; by Anton, in 29 per cent.; by Schulz, in 30 per cent.; by Kirn, in 33 per cent.; and by Preston, Bristowe, and the Bavarian army report, in 3 per cent, of the cases.
Lowenstein describes a "hemorrhagic angina." Hemorrhages from the gums, root of the tongue, and pharynx are often mentioned in the literature. (Compare pp. 602 and 603 upon this point.)
Vomiting has very generally and correctly been described as a frequent initial symptom of influenza. Anton observed it in 21 per cent., and Stintzing in 25 per cent., of their cases.
The bowels may be regular or costive; diarrhea is less common; Stintzing found the latter in25 per cent.; Schulz, in 20 per cent,; Krehl, in 13 per cent.; Anton, in 8 per cent., of their cases. The most detailed account is by Bristowe. He found the bowels normal in 72 per cent., constipation in 11 per cent., and diarrhea in 12 per cent,, of his cases.
If in any case the phenomena of a severe intestinal influenza (diarrhea, meteorism) are combined with those of the nervous form (headache, delirium, apathy), and more especially if there is also high protracted fever, we get the much quoted "typhoid form of influenza." The clinical picture becomes yet more deceptive if, at the same time, the tongue is dry or roseola appears; Teissier often observed this latter. Curschmann, in the Leipsic clinic, found it in 1.2 per cent, of all the cases of influenza. But we have called attention above to the fact that there is but rarely any serious difficulty in the differential diagnosis between typhoid influenza and enteric fever. Often a single symptom will suffice to clinch the diagnosis of influenza, for example, the sudden onset with rigors and immediate high fever, or the occurrence of herpes labialis, or the intense initial head, back, and joint pains, or the appearance of hyperidrosis universalis. There is frequently a resemblance to enteric fever, but the tongue is then quickly covered, as if by cement, a symptom of the gastric variety of influenza only, and the diarrhea is different to that of typhus abdominalis, etc.
There is no doubt that, as in all the complications of influenza, the typhoid forms occurred with special frequency in certain places (Wor ner, Teissier, Trechsel).
Very remarkable is that form of influenza-it might be called the metamorphous variety-which is at first entirely gastro intestinal, and then in a few days suddenly changes into the respiratory variety, with diffuse bronchitis and pneumonia. At the same time the gastrointestinal phenomena fall into the background. The sudden change of the clinical picture in these cases often is very surprising.
One addition to the pathology of influenza furnished by the most recent epidemic is the demonstration that influenza may give rise to acute hemorrhagic gastritis and enteritis, and sometimes, as a sequel, also to peritonitis.
Many cases of simple intestinal hemorrhages, as well as of severe bloody, mucous, dysenteroid diarrhea, in influenza, have been described (Lanclgraf, Enggesser, Furbringer, B. Auerbach, Warfvinge, Melin, Lennmalm, German army report, official report from Bavaria, from Switzerland, etc.). The intense hyperemia of the intestinal mucous membrane frequently found upon postmortem examination, with the addition of ecchymosis and streaky hemorrhages, is sufficient to account for the simple intestinal hemorrhage. This variety of hemorrhage from the intestine is analogous to epistaxis and to the influenzal hemorrhages of the pharynx, larynx, and bronchi.
This hyperemia of the intestinal mucous membrane may progress to inflammation, necrosis, and ulceration. We quote Jiirgens, who in postmortem examination of many cases of influenza found "severe ulcerative or hemorrhagic pathologic conditions of the gastric and intestinal mucous membrane. In the stomach broad, often long, but not deep ulcerations of the gastric and intestinal mucous membrane, which, besides being markedly hemorrhagic and hyperemic, were intensely swollen and edematous. The submucosa and, to a certain extent, the muscularis also, were edematous and the seat of cellular infiltration, as in commencing phlegmonous gastritis. With marked hemorrhagic enteritis there was also considerable swelling of Peyer's patches."