In an attack of acute pleurisy the ordinary diet for a febrile illness is to be employed. When effusion takes place, either as the result of an acute attack or in a chronic form, more special treatment as regards the diet has sometimes been carried out. Attempts have been made by means of a dry diet, i.e. with the fluid elements reduced to a minimum, to check further effusion, and to procure absorption of the fluid. As a rule this process is an extremely irksome one to the patient. The therapeutic results do not seem to justify this mode of treatment. In the case of pleurisy one is dealing with an active inflammatory process, and an excess of secretion goes on in spite of a limited fluid intake. In cases of chronic effusion, after the subsidence of active inflammation, the fluid can be removed much more quickly by other measures, and with much less discomfort to the patient than by deprivation of fluids and fluid food. On the other hand it is not advisable to encourage a large fluid intake on the part of the patient during the stage of effusion, but rather one will try to keep the amount of fluid given in strict moderation. Again, the employment of a salt-free diet, however useful it may be in certain cases of renal oedema, is not to be regarded as a remedial measure in pleural effusion. Diuretic drinks are, as a rule, of no effect. With reference to the diet, the only clear indications are to maintain the patient's strength by as full a diet as the state of the temperature and digestion will allow of.

The other diseases of the lungs do not call for any detailed notice. Broncho-pneumonia or catarrhal pneumonia is to be treated as a fever of varying length and with the same precautions as lobar pneumonia. That is to say, the diet must be regulated so far as possible with a view to leave the pulmonary action unimpeded. In the case of infants it may be regarded as a specific fever, or as a complication of specific infection, and the diet should be regulated accordingly (see Chapter X (Diet In Fevers And Acute Infectious Diseases)).

Hay fever is an acute febrile disorder, which does not as a rule call for any special dietetic treatment, except in that form which is associated with asthma. In the latter case the precautions and limitations already described ought to be fully carried out (see Asthma).

Emphysema is not very amenable to direct treatment by means of diet, but the comfort of the patient will be maintained by a regimen similar to that described in connexion with Chronic Bronchitis (q.v.).