1. Catarrh

If we leave out of view the catarrhs of the fauces and pharynx, which we consider afterwards, Simple catarrh of the mouth is exceedingly rare as a primary disease. It is not infrequent, however, as a secondary affection, arising from the irritation of carious teeth, from the use of mercury, the presence of ulcers, etc. It is also of frequent occurrence in the acute fevers, especially typhus, scarlet fever, small-pox, and measles. In these fevers there is also a catarrh of the stomach, and the inflammation in both seems due to the action of the morbid poison in the blood.

The mucous membrane is swollen and red and there is greatly increased desquamation of the epithelium, especially inside the cheeks and on the tongue. The desquamated epithelium is mixed with leucocytes, serous exudation, and mucus in varying proportions, and on that account it has varying characters. On the tongue there is usually much epithelium which lies on the surface, and so a tolerably thick layer is formed mostly of a whitish or yellowish colour - Furred tongue. On the cheeks and gums there is more fluid and less epithelium. In the midst of the epithelium and leucocytes bacteria and leptothrix and fungus threads are to be found, indeed, the thick deposit on the furred tongue is largely composed of microbes of many kinds. If the patient is feverish and lies with the mouth open, the catarrhal products dry-in and form a dirty brownish coating of the tongue and gums which goes under the name of Sordes.

Sometimes the inflammation centres especially around the mucous glands, and they may form prominent nodules or vesicles. To this form the name Follicular stomatitis has been given; it is frequently seen in children during dentition or after measles, and is often associated with catarrh of the stomach or intestine. The vesicles or small prominences frequently burst and leave multiple small ulcers covered by a dirty exudation.

Catarrh of the mouth rarely assumes a phlegmonous character, in this respect contrasting with inflammation of the fauces.