432 DISEASES OF THE MOUTH. 



sensitiveness of the mouth to mercury varies with the individual; 

 hence, in one patient stomatitis may occur sooner than in another, just 

 as, after frictions on the skin with mercurial ointment, one person is 

 affected earlier than another with the superficial dermatitis, which we 

 shall hereafter describe as eczema mercuriale. 



2. In many cases, oral catarrh is a propagation of inflammation 

 from neighboring organs to the mucous membrane of the mouth. 

 Wounds and inflammations of the face, particularly facial erysipelas, 

 also inflammations of the fauces, are almost always complicated with 

 oral catarrh. Less constantly, nasal and bronchial catarrh extends to 

 the mouth. While a thickly-coated tongue was considered a certain 

 sign of disturbance of digestion, this secondary catarrh caused facial 

 erysipelas and angina to be almost always regarded as manifestations 

 of gastric disturbance, and to be treated accordingly. Acute and 

 chronic catarrh of the stomach is surprisingly often complicated with 

 catarrh of the mouth. Beaumont, who had the opportunity of com- 

 paring the gastric mucous membrane with that of the mouth, in the 

 case of the Canadian, 8t. Martin^ found that changes in the former 

 instantly excited analogous changes in the latter, and daily experience 

 supports this observation. But, although catarrh of the mouth very 

 frequently accompanies catarrh of the stomach, we must not sup- 

 pose, on the other hand, that gastric catarrh occurs with every oral 

 catarrh. 



3. Catarrh of the mouth is not unfrequently a symptom of consti- 

 tutional affection. Among the acute infectious diseases, typhus and 

 scarlatina especially are accompanied by peculiar changes of the mu- 

 cous membrane of the mouth, which are essentially catarrhal ; these 

 will be more accurately described when speaking of the diseases in 

 question. Coated tongue is found in almost all feverish affections ; 

 but it would be going too far, to say catarrh of the mouth occurs in 

 every fever (see treatment). 



Finally, in many cases we do not know the exciting causes. 

 Pfeuffer gives sitting up at night, and other observers give mental 

 excitement, as a cause. 



It is remarkable that in some patients oral catarrh obstinately per- 

 sists for years, without our being able to find any continuous cause. 



ANATOMICAL APPEARANCES. We seldom have the opportunity 

 of observing oral catarrh in its incipient stage. Only after severe irri- 

 tation, and occasionally during difficult dentition, we see the oral mu- 

 cous membrane at first dark red and very dry, till, finally, in the stage 

 of decline, there is a copious secretion, which is clouded by contain- 

 ing young cells. After less severe irritation, and in the oral catarrh 

 which usually complicates catarrh of the stomach, the intense redness 



