In a way similar to the involvement of the Eustachian tube, the process may spread to the lachrymal canal and even to the conjunctiva (see conjunctival diphtheria).
Extension of pharyngeal diphtheria to the larynx and trachea is somewhat less frequent (one-fourth to one-third of all cases) than to the nasal cavities, although different epidemics may show great variations. Occasionally a continuous membrane is seen extending from the pharynx to the glottis; but as a rule, the larynx becomes involved suddenly on the fourth or fifth clay. The primary deposit in the pharynx may not increase, on the contrary it may have begun to lessen, when sudden and unexpected symptoms of croup develop. The onset may be stormy with high fever, prostration, decided swelling of the lymph-nodes, and albutninuria, or it may be more gradual, with moderate irregular fever and less disturbance of the general condition.
The first symptoms are tickling or pains in the neck, a character istic weakening of the voice, a short, rather brassy cough and a more prolonged character to the breathing. Decided hoarseness develops rapidly, the cough becomes hollow and barking and the breathing is slower, more labored and noisier.
A laryngoscopic examination shows that the symptoms are mainly the result of a swelling and congestion of the mucous membrane, and also partly due to the beginning of fibrinous exudation.
As the case progresses, respiration becomes so embarrassed that the patient is anxious, as shown by the attitude and expression. Voice and cough become almost completely silent.. Inspiration and expira tion are noisy, lengthened (especially expiration) and extremely labored. The increasing air-hunger brings into play all the voluntary accessory muscles of respiration, so that the thorax is elevated and finally is almost constantly held in the position of inspiration. The number of respira tions is somewhat increased to twenty-eight or thirty to the minute. Nevertheless, the volume of air entering the lungs gradually becomes insufficient to counterbalance the external atmospheric pressure and the parts surrounding the thorax begin to sink in more and more with each inspiration, the suprasternal notch, the supraclavicular fossa, the epi gastrium and in raehitic children the lower ribs. The larynx is drawn
down with inspiration.
Although the amount of air entering with each inspiration is so small, yet it suffices, owing to the incomplete expiration, to distend the lungs gradually and to bring about a permanent position of inspiration, so that the lower border of the lungs is depressed. The condition of the patient begins to be wretched, the air-hunger causes excitement, which becomes greatly increased when the respiration is temporarily com pletely interrupted by loose particles of membrane or mucus. These attacks of asphyxia usually last for only a fraction of a minute, during which the child tosses about in anxiety, the features become cyanosed, the staring eyes seem to start out of the head, beads of cold perspiration come out on the forehead, from time to time the crowing inspiration can he heard at a distance—and death follows unless the obstruction is coughed up, frequently in the form of a more or less complete fibrinous cast of the windpipe (Fig. 89 shows such a cast which extended even to the bronchi of the third division). After the attack the child is ex hausted and lies bathed in perspiration; the breathing is better but not easy. Renewed formation and exfoliation of the membrane may cause the attacks to be repeated after six or eight hours.
Laryngoscopic examination in the stage of stenosis is exceedingly difficult and one should hesitate to do it. If feasible, it shows a spread of the fibrinous exudate with islands of deposit, some of them confluent, in the interarytenoid space and the subglottic region; or, in extreme cases, a single, uniform whitish yellow (macaroni-like) membrane, ex tending from the posterior surface of the epiglottis over the false_ and true vocal cords and on down deep into the trachea. The rima glottidis looks like a narrow, immovable cleft, whose range of excursion is lim ited particularly by the drawing together of the arytenoid cartilages by fibrinous bands which prevent any movement of abduction (Piniazek) (Plate 21).