This section is from the book "The Chronic Diseases, Their Specific Nature And Their Homeopathic Treatment", by Samuel Hahnemann. Also available from Amazon: The chronic diseases, their specific nature and their homeopathic treatment.
But still, even in such favorable external relations, as soon as these persons advance in age, even moderate causes (a slight vexation, or a cold, or an error in diet, etc.) may produce a violent attack of (however only a brief) disease: a violent attack of colic, inflammation of the chest or the throat, erysipelas, fever and the like, and the violence of these attacks seems to be out of proportion to its moderate cause. This is mostly wont to happen in fall or winter, but often also by preference in springtime.
But even where a person, whether a child or an adult, who has the Psora slumbering within him, shows much semblance of health, but happens upon the opposite of the above-described favorable conditions of life, when his health and whole organism have been very much weakened and shaken by a prevalent epidemic fever or an infectious acute disease,* smallpox, measles, whooping cough, scarlet fever, purple rash, etc., or through an external severe lesion, a shock, a fall, a wound, a considerable burn, the breaking of an arm or a leg, a hard labor, the confinement due to a disease (usually helped on by the incorrect and weakening allopathic treatment), confinement at a sedentary occupation in a gloomy, close room, weakening the vital force; the sad losses of beloved relatives bending down the soul with grief, or daily vexation and annoyance, which embitter the life; deterioration of the food or an entire want of what is necessary and indispensable, exposure and inferior food beating down man's courage and strength; then the Psora, which has hitherto slumbered, awakes and shows itself in the heightened and augmented symptoms enumerated below, in its transition to the formation of severe maladies; one or another nameless (psoric) chronic diseases* breaks out and, most of all, through weakening and exhausting improper treatment by allopathic physicians, they are aggravated from time to time without intermission, often to a fearful height, if external circumstances favorable for the patient do not interpose, and cause a moderation in the process of the malady.
*At the termination of an acute fever there often follows, as if incited by such a fever, an appearance of an old Psora residing in the body, as an eruption of itch. This the physicians explain as a new generation of itch in this individual body replete with bad humors (scilicet), since they know nothing of a Psora in man which may be quiescent for a long period. But the itch-disease cannot now be generated or arise or be created anew of itself, just as no smallpox or cowpox, no measles, no venereal chancre disease, etc., can now make its appearance with any man without previous infection.
*The one or the other disease, according to the original bodily constitution, a peculiar mode of living. a peculiar disposition of the mind, often arising from'the individual education or a more receptive or more weakened condition of .some part of the body, gives a peculiar direction to the disease, and thus causes the itch disease to lead to the origin of the one or the other disease, so as to show itself preferably in that one direction and develop itself in that particular modification. A passionate, peevish disposition gives an extraordinary predisposition to the development of the Psora; so, also, previous exhaustion through frequent pregnancies, excessive nursing of infants, extraordinary hardships, exhausting erroneous medical treatment, debauchery, and a profligate mode of living. The internal itch disease is, as before mentioned, of such a peculiar nature that it may remain, as it were, tied down and covered up for a long time through external favorable surroundings, so that a man may seem to the superficial observer healthy for years, even . for many years, until circumstances unfavorable to the body or the soul, or to both, may arise and serve as a hostile impulse to awaken the disease slumbering within and thus develop its germs. His acquaintances and his physician, yea, the patient himself, can not then comprehend how his health could so suddenly fall into a decline. To bring some examples for explanation from my own experience: After a simple fracture of a limb attended with confinement to bed for five or six weeks, there may follow diseased conditions of another kind, the cause of which cannot be guessed, which diseased conditions, even when measurably removed, nevertheless return, and which, even without any error in diet, nevertheless at their return show aggravation. This is mostly the case in fall (winter) and spring and becomes a tedious ailment increasing from year to year, a lasting cure for which, without the substitution of a known, and the customary allopathic treatments, with their aggressive, inappropriate remedies - such as baths, Mercury, Prussic acid, Iodine, Digitalis, Qui has broken out, true health can not be lastingly restored by any of the modes of treatment hitherto nine, starvation and other fashionable remedies included - only hasten death, the end of all those maladies which the physician cannot heal.
But even if favorable external conditions should again check the rapid development of a disease that still worse disease for it by an allopathic cure, has been hitherto vainly sought for in the councils of former physicians and also in visits to mineral springs. There are in man's life innumerable stumbling-blocks or unfavorable occurrences of this kind which serve to awaken the Psora (the internal itch-disease), which till then has been slumbering (perhaps for a long time previously), and which cause its germs to develop. They are often of such a nature that the grave evils which gradually follow on them are out of all proportion to them, so that no rational man can consider those occurrences as sufficient causes for the chronic diseases which follow and which are often of a fearful character. But such a man is compelled to acknowledge a deeper seated hostile cause of these appearances, which cause has only now developed itself.