CROUP (synonym, Cynanche trachealis), a common and dangerous form of disease, occurring chiefly in young children. Its essential nature is an acute inflammation of the air passages, particularly the larynx and trachea, accompanied with the exudation of a fibrinous material or "false membrane " which spreads over the interior of the tube, narrowing its calibre, and thus obstructing respiration.

Croup occurs most frequently in the second and third years of life, although it may affect children of any age. It is exceedingly rare in adults.

The attack sometimes comes on suddenly in the night without previous warning, but in general some premonitory symptoms exist in the shape of the phenomena of a common cold or catarrh, which may precede the onset of the croup for several days. There is a slight hoarseness of the voice and an occasional cough of a peculiarly harsh or brassy sound, together with a feeling of pain in the throat and breast, and a high degree of feverishness and general disturbance. The disease soon assumes its characteristic features. The loud croupy cough comes on in frequent paroxysms, and is attended with an increasing difficulty of breathing, the respirations partaking of the shrill metallic noise of the cough, while the voice is reduced to a hoarse whisper. The child lies with the head thrown back, making strong efforts to breathe, the countenance indicating intense suffering and anxiety. At first little or nothing is expectorated with the cough, but as the latter increases, fragments of the so-called false membrane are brought up into the mouth, with the effect of affording some temporary relief to the breathing. The power of swallowing is not much impaired. Should the attack undergo no abatement, symptoms of asphyxia soon make their appearance, The surface of the body becomes livid, the respiration long drawn out and laboured, while the cough continues to recur in fits which threaten instant suffocation. Drowsiness or coma succeeds ; and death takes place, either gradually from exhaustion, or suddenly in the midst of a suffocative paroxysm. Throughout the whole course of the disease remissions in the severity of the symptoms are common, and generally occur during the daytime, the attack re-turning with all its violence as night approaches. In favourable cases the symptoms undergo gradual abatement, and there is a speedy return to health, but it is to be borne in mind that one attack of croup appears to predispose to another, and relapses are not uncommon.

The inflammatory product, or false membrane formed in the air passages in the course of an attack of croup, varies both as to its amount and the extent of its distribution. It may consist merely of a thin white film covering portions of the windpipe, or on the other hand it may have the character of a tough compact membrane of several lines in thickness, and may extend from the upper part of the larynx down to the ramifications of the bronchial tubes. It ad-heres closely to the mucous surface, and although large portions are occasionally detached by coughing or vomiting, the false membrane appears to be reproduced with great rapidity. It is the chief source of danger in the disease, and where it has spread downwards into the bronchial tubes death by asphyxia is the rapid result.

Croup is apt to be complicated with other serious diseases, such as bronchitis and inflammation of the lungs, and it may also be accompanied with many of the pheno-mena of diphtheria, in which case it has been named diphtheritic croup. This latter form of the disease is some-times observed when croup occurs in connection with some of the infectious diseases, such as measles, scarlet fever, or small-pox. On this point it ought to be stated that much discussion has from time to time taken place respecting the relation of croup to diphtheria, not a few eminent authorities holding that in all essential points they are one and the same disease. The generally prevailing opinion, however, among physicians who have had extensive opportunities of observation, is, that while many points of similarity exist betwen croup and diphtheria they cannot be regarded as identical. See DIPHTHERIA.

Croup has sometimes appeared in an epidemic form. This was the case in the year 1805-7, when it spread over a large portion of the continent of Europe. In the last-named year an inquiry into the nature of the disease by the faculty of medicine of Paris was ordered by Napoleon I.,

whose nephew, the crown-prince of Holland, had fallen a victim to the epidemic, and who offered a prize for the best essay on the subject. Besides the two prize essays of MM. Jurine and Albers, many valuable treatises were written, and it is to the information thus obtained that much of our present knowledge of this malady is due.

Croup is a disease of northern climates, and of low-lying, damp, and cold localities. The exciting cause of an attack Í3 generally exposure to cold, particularly cold winds, such as prevail in winter and spring. There appears to be in some families a special liability to this disease, as shown in the readiness with which the children are attacked on Blight exposure. Male children appear to be more fre-quently affected than female. Croup is not contagious.

The mortality from croup is very great, and it has been computed that about one-half of those in whom the attack is developed die. Its course is in general rapid, seldom exceeding three or four days. It sometimes proves fatal in less than one day, while again recovery may take place after several days' severe suffering.

With respect to the treatment of croup, it may be stated that in few acute diseases aré greater vigilance and more prompt and energetic measures requisite. The disease in many cases hastens on with such rapidity that as regards treatment the loss of a few hours may be fatal to the patient. In the earlier or premonitory stage, when the only symptoms present are hoarseness and some amount of croupy cough, it is essential that the child should be kept in a warm temperature, while warm baths and medicines to promote perspiration, such as small doses of antimonial or ipecacuanha wine should be administered. The abstrac-tion of blood by one or two leeches over the upper part of the' breast-bone is recommended by many physi-cians when the child is robust and the attack violent. When the breathing becomes embarrassed the adminis-tration of emetic doses of the above-named medicines, or of the sulphate of zinc or of copper, are of great use, as in the act of vomiting portions of false membrane may bo dislodged and expelled from the air passages. The child should be surrounded with an atmosphere of steam (see BRONCHITIS), and fomentations, by means of a sponge or piece of flannel dipped in hot water, applied to the neck. Abundance of liquid nutriment may be given, thirst being always present. When remedies such as those now indicated fail to afford relief, and the child threatens to die from asphyxia, the question of tracheotomy has to be con-sidered as a last resource. This operation has so often succeeded in croup as to justify its being resorted to in the circumstances now described. Indeed, in the opinion of many competent authorities, more lives might be saved were the operation performed earlier in the course of the attack than is commonly the case. However this may be, it is certain that not only are many children thus rescued from death, but even where the operation fails to accomplish this, suffering is greatly mitigated and death rendered easier.

What is known as SPASMODIC CROUP (synonyms, False Croup, Laryngismus stridulus, Spasm of the Glottis, Child-Crowing) bears some resemblance to the disease above described as regards its chief symptom, but differs from it entirely as to its patholog}'. This affection occurs mostly in young infants during dentition, and manifests itself by a sudden and violent interruption to the breathing, during which the attempts to inspire are accompanied with a noise resembling the crowing of a cock. Unlike true croup this disease is unattended with fever or inflammation of the air passages, and is a purely nervous ailment depending on the irritation of the nerves which regulate the closing of the aperture of the glottis (the upper part of the Lrynx). This irritation is usually of reflex origin, being due to some disturbance at some distance from the part, as teething or disorders of the stomach or bowels, all of which, as first shown by Dr Marshall Hall, have the effect of bringing on attacks of this kind. The attack is sometimes precipitated in a child liable to it by exposure to a cold wind, or by its being violently tossed in the arms of a nurse. The nervous origin of the seizure is farther proved by the fact that the child-crowing is often accompanied by marked contraction of the muscles of the fingers and toes, and also sometimes by convulsions. During the spasm all the symptoms of asphyxia are rapidly developed, and unless relief is speedily obtained death may suddenly take place. The attack often passes off with a forcible expiratory effort, after which the child lies quite exhausted. The paroxysm, however, is apt to return. Like croup, a liability to this disease may run in families, and sometimes with disastrous results. The treatment must bear reference to any cause likely to have given rise to the attack. For relief during the paroxysm efforts to make a sudden impression on the nervous system should be used, such as warm baths or cold affusion to the surface of the body. Artificial respiration ought to be tried where death threatens from asphyxia, and tracheotomy performed, if time be sufficient to make the attempt. (J. O. A.)