The subjective symptoms accompanying the affection of the epiglottis are not always in direct proportion to the extent of the membranes. Dyspnoea and hoarseness occasionally occur where the only abnormal condition is a marked oedema at the entrance of the larynx, particularly of the posterior wall near the arytenoid cartilages and the attachment of the vocal cords. The oedematous condition causes a functional paralysis of the vocal cords, together with marked dyspnoea on inspiration. The difficulty of breathing may become so excessive that the clinical diagnosis of croup is unquestionable, and tracheotomy resorted to, while expiration is comparatively free and the voice not markedly affected. Furthermore, cases occur in which there is no marked oedema, but merely a general catarrh of the epiglottis and larynx; here, too, the subjective symptoms of hoarseness and dyspnoea may become severe and necessitate the performance of tracheotomy. Still, bearing this in mind, I have on several occasions refrained from performing this operation where I judged that, aside from the diphtheria of the pharynx, I had to deal with a moderate oedema of the glottis or a laryngeal catarrh.

Frequently, however, membranes form in the larynx in the same way as in the pharynx or nose; then inspiration and expiration are equally interfered with, and hoarseness is a more constant symptom than in the above-mentioned cases. Fever and pain are not necessarily prominent symptoms; in fact, they are frequently unimportant, but in proportion as the degree of narrowing of the larynx increases the respiration becomes more difficult, long-drawn, and loud.

It may happen that the trachea and bronchi may become affected, although diphtheria of the fauces does not exist. This does not occur as rarely as Henoch and Oertel seem to believe. They think that diphtheritic tracheo-bronchitis is mistaken for the primary condition, because the throat is not examined early enough.

Oertel is of the opinion that the membrane in the fauces is overlooked in such cases. Steiner,11 too, asserts that "the tendency of the times is to question, nay, rather to deny, the existence of croup extending from below upward." Now, on the contrary, repeated experience enables me to assert with positiveness that diphtheritic tracheo-bronchitis may occur without an affection of the pharynx at the same time. I do not deny that it may last for days without giving rise to dangerous symptoms. I know it does. But when the process reaches the larynx, the symptoms of suffocation become so urgent that tracheotomy may be absolutely required at once, and, in spite of the operation, death soon after occurs.

11 Ziemssen's Handb., iv., 1, 126.

Of course these cases are exceptions; as a rule, laryngeal and tracheal diphtheria result from a descent of the disease from the fauces. More or less uncomplicated cases of primary laryngeal diphtheria, or so-called sporadic membranous croup, were, however, observed before the end of the sixth decade of this century. They were then almost the only cases of diphtheria, and linked former epidemics and the present one together.

Inflammatory affections of the lungs may occur at various times and in various forms during an attack of diphtheria. That which appears after tracheotomy is usually a broncho-pneumonia, and results from rarefaction of the air in the respiratory passages during the period of impeded respiration, with consequent collapse of pulmonary tissue and dilatation of the blood-vessels, and hence a disturbance of the circulation. It may not fully develop until after tracheotomy, and is a frequent cause of death on the second or third day after the operation. Now and then a case of lobular pneumonia will result from the aspiration of pieces of membranes into the smallest bronchi. It can be easily recognized when the trachea is opened, but previous to the operation the auscultatory signs are of little or no value, being masked by the laryngeal râles. Percussion is equally useless, for a dulness may just as well indicate collapse of the lung as infiltration. The second form of pneumonia associated with diphtheria is from the beginning fibrinous in character. Here, too, auscultation and percussion are of little assistance in establishing a diagnosis when there is a laryngeal diphtheria at the same time, for the above reasons. Where, however, the dulness on percussion is accompanied by high fever, and the long-drawn inspiration is replaced by rapid respiratory movements, the diagnosis of pneumonic complication is justified.

Diphtheria of the mouth, as a primary affection, is not of very frequent occurrence; not rarely, however, is it associated with diphtheria of the fauces and nose, mainly when they have assumed a septic or gangrenous character; it appears on cheeks, tongue, angles of the mouth and gums, and, after the fetid discharges have excoriated the skin, on the lips also. In all of these localities it appears less in the form of an extensive, thick membrane than an infiltration of the tissues. It is most apt to occur where, from the start, the mucous membrane of the mouth was eroded or ulcerated. The ulcerated base of a follicular stomatitis is very frequently the starting-point of a general diphtheria of the mouth. It is always a disagreeable symptom, points to a long duration of the whole process, and threatens septic absorption.

The oesophagus and the cardiac portion of the stomach are the seat sometimes of very massive and extensive, mostly fibrinous exudations, in typhoid fever, dysentery, cholera, measles, and scarlatina, or after injuries following contact with mineral acids, alkalies, corrosive sublimate, or antimony. When the normal tissue was not injured I never saw any that were not superjacent and could not easily be peeled off (croupous). In cases of extensive pharyngeal and laryngeal diphtheria the upper part of the oesophagus is often covered to a distance of half an inch or an inch with membrane, the lower part of which is thinning out into a mere film. A case of local diphtheritic deposit near the cardiac portions of the oesophagus, upon the seat of a stricture, I have described in my Treatise, p. 83. Actual diphtheria of the stomach is rare. So is that of the intestine, which is much more liable to be affected in animals than in man. In the cow intestinal diphtheria is frequent (Bollinger). In the gall-bladder, resulting from the irritation produced by calculus, it was seen by Weisserfels. The diphtheritic form of inflammation of the human colon and rectum—dysentery—is frequent enough, but will be the subject of discussion in another place. But, besides this, in the lower portion of the small intestines and in the colon long, tough, coherent membranes are sometimes found in the male and female (not in the hysterical female only). As a rule they are not diphtheritic, but consist mostly of nothing but mucus hardened and flattened down by protracted compression. The few cases of intestinal diphtheria I have met with gave rise to the usual symptoms of enteritis, and were diagnosticated as such.

Wounds of all kinds are easily and rapidly infected by diphtheria; for instance, vaginal abrasions and erosions of the external ear, tongue, and corners of the mouth. Scarification or removal of part of the tonsils is followed in half a day or a day by a deposit of diphtheritic membrane on the wound. The wound caused by tracheotomy becomes liable to be infected with diphtheria within twenty-four hours. Leech-bites, skin denuded by vesicatories, removal of the cuticle by scratching during cutaneous eruptions, all furnish a resting-place for diphtheria in a short time. What Billroth has described under the name of muco-salivary diphtheritis, as it occurs after the extirpation of a large portion of the tongue and resection of the lower jaw, belongs to this class.