This section is from the book "A Treatise On Therapeutics, And Pharmacology Or Materia Medica Vol1", by George B. Wood. Also available from Amazon: Part 1 and Part 2.
Scrofulous Inflammation of the Serous Tissues. This often exists in connection with tubercles, as already stated in reference to the peritoneum. The pleura, pericardium, and synovial membranes are similarly affected. Whether scrofulous inflammation occupies these tissues without tubercles may perhaps be considered uncertain; but analogy is in favour of the opinion that it does so; and, in relation to the arachnoid, or at least the subarachnoid tissue, and the synovial, analogy is strongly supported by facts. Extensive tuberculization of the proper serous tissues is almost always sooner or later fatal; but the event may probably be postponed by the use of the oil; and, in cases where the inflammation may be supposed to exist without tubercle, the remedy would probably prove occasionally curative. Hence, in chronic cases of these affections, the oil should be employed, not only to correct the diathesis as far as possible in the positively tuberculous cases, but as a curative measure, in the hope that the symptoms may depend simply on inflammation. I have seen cerebral symptoms in infancy, which seemed strongly to threaten chronic hydrocephalus, and were associated with other evidences of scrofulous cachexia, yield happily to this remedy.
Phthisis. The principles upon which cod-liver oil is given in this complaint have been already stated. All that can be hoped for from it is, by improving the constitution, to correct the tendency to the deposition of tubercle, and to support the system during the exhausting process of its discharge. Unfortunately, the diathesis is often so strong, so intimately incorporated as it were with the inherited constitution of the patient, that no known influence is sufficiently powerful to eradicate it; and, though it may be postponed, the fatal result is in most cases inevitable. This much, however, may be said in favour of cod-liver oil, that no one medicine, and no combination of medicines are known, which nearly equal it in efficacy. I believe that, if used before tubercle has been produced, it will not unfrequently prevent it; that, even after a moderate amount has been deposited, it will sometimes arrest its progress, and ultimately save the patient; and that it may, in some few cases, even in the advanced stage of the disease, and after cavities have been formed, rescue from death, if the quantity of tubercle already existing be not sufficient fatally to disorganize the lungs. Of this I have no doubt, that, if begun with early, and used perseveringly, with the aid of other measures calculated to invigorate the general health, it is capable of considerably diminishing the amount of mortality from this fearful disease. All agree that it will often prolong life, when unable to preserve it, and that it very much contributes to the comfort of the patient, especially in the advanced period of the complaint. There is no stage, from the beginning to the close, in which it may not be given with reasonable hope of benefit. The misfortune is, that it is often given insufficiently, being abandoned too early, or taken irregularly, or in too small a quantity; and that patients, in consequence of its unpleasant effects on the palate or the stomach, will not, or, from the irritability of that organ, cannot take it in the requisite amount, or for the requisite length of time. No material effect need be looked for under two or three weeks; and it should not be abandoned, unless after a totally fruitless trial of six weeks or two months. When found useful, it should be persevered with for months or years; and, even after the apparent restoration of health, the least sign of relapse should be the signal for its resumption. In the inherited cases, there is a natural proclivity to the disease, which, though it may be corrected for a time, will again and again evince itself when the restraining cause is removed; and the only chance of safety is in the unremitting use of the proper measures, even when symptoms of disease have disappeared, until, in the spontaneous changes which the system undergoes in the advance of life, the original tendencies may have been subverted.
But it is not in the scrofulous affections only that cod-liver oil is useful. There are other diseases, connected with a cachectic condition of the system, in which it has enjoyed much reputation.
Chronic Rheumatism. This is one of the complaints in which the oil was first used. It has been particularly recommended in chronic lumbago and sciatica, and in obstinate swellings and deformities of the joints. It is no doubt beneficial in some of these cases; but I think it highly probable that not a few of the latter, which were taken for rheumatic, were really scrofulous, and that the remarkable efficacy of the oil may be in part ascribed to that cause. In the Pennsylvania Hospital, I have repeatedly witnessed cases of obstinate and painful swellings of the knee, ankle, or hip, which may possibly have been at first rheumatic, and had been treated as such for months without success, which wen-attended with great emaciation, a frequent pulse, night-sweats, and other evidences of debility, and were going on in a steady course of deterioration, that threatened death in the end. These cases, under the impression that they were really scrofulous, having either been such in the beginning, or assumed this condition in their progress, I have treated with cod-liver oil, aided by rest, nourishing food, and auxiliary medicines, as iron, quinia, and iodide of potassium, and with the happiest results. At the usual period after the commencement of the remedy, they have begun to exhibit signs of amendment, and have gone on, steadily though gradually, to a perfect cure. How much of the result was ascribable to the oil, and how much to the auxiliary measures, it would be difficult to decide; but my impression on the whole is that, without the oil, I should have been much less successful. The remedy has been recommended in chronic gout, but is less efficacious.
Rickets. Perhaps in no disease does the oil display greater powers than in this, occurring in early childhood. Infants, affected with the disease, often begin to improve in a few days under its use, and rapidly advance to complete recovery.
Besides the affections above mentioned, the oil may be used in chronic anaemia and chlorosis, in paralysis with debility, and in various nervous affections associated with impoverished blood. It has sometimes proved beneficial in neuralgia, probably from this cause. Amenorrhoea has sometimes yielded to it; probably through its influence over the blood-making function.