It is not in every case that the onset of the disease is so marked as de scribed above. The illness often begins insidiously and is only discovered by the pallor of the child, and the shortness of his breath on any exertion. The latent form of the disease is especially common in infants, particularly if the child is suffering at the time of the attack from any wasting disease. In these cases there is often no fever, or only a trifling rise of temperature ; there may be no cough ; and attention may only be directed to the chest by noticing that the child is breathing quickly and has less appetite than usual for his food.
The pain of pleurisy is usually only severe at the beginning of the ill ness, and often subsides as effusion takes place into the pleura. This is not, however, always the case. Sometimes it continues with extreme ten derness of the affected side until towards the close of the disease. Unless the tenderness be great, the child usually lies on the affected side for the sake of giving increased freedom to the healthy lung, which has to do double duty as a respiratory organ. If the tenderness is marked, the pa tient lies on his back. It is not often that he is seen resting on the sound side.
If the disease continues for two or three weeks, the fluid usually becomes purulent. There are, unfortunately, no positive symptoms which indicate that the effusion is no longer serous. Even the time which has elapsed from the beginning of the illness is no positive guide, for in some children the fluid becomes purulent much more quickly than it does in others ; and in exceptional cases it may be purulent from the first. The tint of the face is, however, often a suspicious symptom. For many years I have been accustomed to note the colour of the face in children the subjects of pleu risy. In many it assumes a peculiar straw-yellow hue which is unlike the complexion of any other disease. This symptom is rarely seen during the first week of the illness, and seldom attracts the eye before the end of the second week. If well defined, it is often coexistent with purulent change in the contents of the pleural cavity. Still, I have seen it well marked in a case where the fluid withdrawn by the aspirator was perfectly clear. A boy in the East London Children's Hospital, aged six years, was noticed to have a most marked straw-yellow tint of the face and neck. The left side of the chest was full of fluid, which had pushed his heart into the epigas trium. With the aspirator, nineteen ounces of clear pale yellow fluid were
withdrawn.
When the fluid has become purulent (empyema) the child usually wastes; but great differences are observed in the extent to which nutrition suffers even in these cases. Much, probably, depends upon the temperature, as this may be taken to indicate with fair accuracy the degree to which the system is fretted by the purulent contents of the thorax. If there be much fever, wasting is rapid. The child has a distressed expression and becomes profoundly anaemic ; his strength diminishes ; the straw tint of the face may spread more or less over the whole body ; the skin becomes dry and harsh, and the fingers get clubbed at the extremities. In very rare cases a trace of oedema may be detected in the legs without albuminuria ; but I have known this symptom to occur only in one instance, and in this albumi nuria followed after a few weeks. Empyema in scrofulous subjects is al most invariably accompanied by fever. The temperature rises to 102° or 103° at night, sinking in the morning to the natural level. In children of healthy constitution the presence or absence of fever appears to depend in a great measure upon the natural nervous excitability of the child and his tendency to respond readily to any source of irritation. In many children with a chest more than half full of purulent fluid the temperature is nor mal and the nutrition fairly good ; and although signs of may be noticed, the strength and spirits are not greatly depressed.
The physical signs in cases of pleurisy in the child must be studied with attention, for they often resemble those of croupous pneumonia very closely. On account of the weakness of vocal fremitus in early life no assistance is to be obtained from the presence or absence of vibration of the chest-wall —a sign which in the adult is of extreme value in the detection of fluid. The auscultatory signs, also, may present so close a similarity to those of inflammation of the lung that, in themselves, without reference to the situa tion in which they occur, they are not distinctive of pleurisy. Indeed, in many cases it is only by a comparison of the physical signs with the general symptoms of the disease that we can arrive at an accurate conclusion as to the nature of the illness.