Chlorosis – Characteristics and History
Diseases are categorized as degenerative, malignant, genetic, endocrine, and so on in current nosology. For the history of disease, we must add a category that we might term “ephemeral.” This requires some license, be-cause many “ephemeral diseases” lasted longer than that term usually implies. Ephemeral diseases comprise a large number of entities that bore working diagnostic names (e.g., typhomalarial fever) for earlier physicians but that are no longer recognized, at least by their previous names.
A historical example of such a disease is the “green sickness,” chlorosis. Although noted in two Hippocratic treatises, the condition received its classic description from Johann Lange in 1554; he called it morbus virgineus. His description contains many elements from the Hippocratic texts, as do accounts by Ambroise Par´e in 1561 and by Jean Varandal (credited with first using the word “chlorosis”) in 1615. For Varandal, chlorosis was a class of syndromes. Reflecting a different approach, Thomas Sydenham in 1683 described many clinical features relied upon two centuries later. Friedrich Hoffmann defined the actual clinical entity in 1731.
Chlorosis was associated almost entirely with Caucasian girls encountering puberty. Still, from clinical observations alone, the etiology remained obscure. Inconsistencies abounded. Not all young women developed the disease at the age of menarche. It struck rich as well as poor. Some, but not all, suffered a morbid ap-petite termed pica (consumption of stones, clay, chalk, and other substances of no nutritional value). Even into the nineteenth century, confusion permeated medical thinking about chlorosis. But by the time of William Osler toward the end of that century, medical opinion had be-come far more confident. The clinical features of chlorosis had been distilled to the point that in many instances the condition could be “recognized at a glance.”
Developments in laboratory medicine brought physicians to something approaching consensus regarding the pathophysiology of chlorosis. By the mid-nineteenth century, reasonably accurate methods were avail-able to determine red-blood-cell counts and hemoglobin content. With this, it became ap-parent that the essential condition of chlorosis was iron deficiency anemia. In the minds of many physicians, chlorosis could now be separated from earlier mimics such as lovesickness, hypochondriasis, and neurasthenia.
The natural history of chlorosis, whether treated with iron or not, remained a matter of dispute. In part, this undoubtedly related to frequent misdiagnoses. Using iron, some physicians reported that a single cure was lasting. For others, the disease progressed to phthisis, many cases of which probably were tuberculosis rather than chlorosis. After iron became a standard treatment, there was general agreement that the disease recurred when treatment was stopped, but responded when iron was reinstituted and continued. If patients remained on the prescribed iron long enough, chronic cases responded as well as those newly diagnosed.
Some observers might look on the use of iron in treating chlorosis before an iron deficiency had been demonstrated as sheer luck, and one more example in the history of medicine where physicians did the right thing for the wrong reason. Yet, although there are many examples of right-thing/wrong-reason in medicine’s past, iron for chlorosis probably is not one of them. When physicians employed proper iron com-pounds in correct doses, the clinical results were dramatic and altogether convincing.
Even if it was correct that the central feature of chlorosis was iron deficiency anemia, a good deal of confusion remained. Still to be elucidated were a host of diseases marked by pallor, wasting, and lassitude, some of which had anemia as a secondary manifestation. These included nephritis, hypothyroidism, subacute bacterial endocarditis, mitral stenosis, and tuberculosis. What did subside was the focus on many factors once considered central but now relegated to a contributory role at most, including lack of fresh air and exercise, corsets, lovesickness with its related sexual frustration, and a variety of uterine disorders.
Chlorosis reminds us of the complex inter-action between physiology and social elements in the genesis of human disease. This interplay is better understood in light of current notions of iron metabolism. To protect the body against the destructive effects of excessive iron, intestinal absorption is fixed at a rate that barely re-places the small amount lost normally. This balance is so exquisite that the prolonged loss of 2 teaspoons of blood daily exceeds the body’s ability to absorb iron from a normal diet, and anemia follows. Iron deficiency anemia can result from decreased dietary iron, increased bodily demand for iron, or loss of blood.
In chlorosis, decreased iron intake came about either from poverty that precluded the intake of iron-rich foods or from cultural influences encouraging young women to avoid meat, eggs, and even milk because of a belief that animal foods increased sexual drive, an undesirable result in Victorian times. The increase in bodily demands for iron resulted simply from the rapid growth associated with adolescence.
The green skin-color of chlorosis, from which it may have derived its name, remains, like the origin of syphilis, one of the fascinating problems in the history of disease. The conundrum appeared when chlorosis was equated with iron deficiency; yet greenish skin in Caucasians was rarely observed in the many cases of hypochromic anemia then being diagnosed. Another possibility is that chlorosis was a misnomer, that the word “green” was used metaphorically to mean immature, raw, or inexperienced.
Significantly, green skin was included only sporadically in clinical descriptions of chlorosis over the years. Lange made no mention of it in his original description. In one study of 27 authors who listed signs of chlorosis, only 16 mentioned greenish skin as characteristic. In an-other analysis of 19 descriptions, only 3 seemed definitely green, 3 possibly so, and 2 yellowish-green. At least it is now reasonable to remove green skin as the outstanding characteristic im-plied by the designation chlorosis.
The incidence of chlorosis in earlier times is impossible to determine. From the attention it received in literature as well as art, one may infer that the condition was not rare. By the end of the nineteenth century, it was viewed as extremely common. This conclusion is all the more striking in light of the rapid exit of chlorosis from center stage. By 1915, medical observers were commenting on the disappear-ance of the green disease. Some concluded that chlorosis had never been anything but a simple iron deficiency anemia brought on by inadequate diet and loss of menstrual blood.
But the condition was not that easily dis-missed, as physicians continued to find chlorosis very much alive. In 1969, it was listed as one of five major categories of hypochromic ane-mia considered diseases sui generis. In 1980, one student of the illness concluded that chlorosis was a functional disease intimately related to anorexia nervosa. Current medical dictionaries still carry the term and define it as an iron deficiency anemia of young women.
Recent revisionist historical work has emphasized the importance of general perceptions of women and their role in what physicians thought and did about disease, although there is surprisingly little about chlorosis as such in this literature. Marxist and social historians have become interested in chlorosis. These revisionist approaches, to varying degrees, tend generally to diminish the importance of pathological physiology in explaining the rise and decline of chlorosis. The more committed the revisionists are to their historical biases, the more difficulty they have squaring their interpretations with those of others as well as with more purely medical explanations. The Marxist, for example, must construct social and political conditions that produced chlorosis in young women of the capitalist class as well as the op-pressed poor, because the evidence is incontrovertible that the condition affected both.
The feminists who would argue that nineteenth century physicians mistreated women consciously on the basis of gender must account for the fact that many of the treatments accorded women by male physicians at the time derived from an inadequate understanding of reproductive physiology and that masculine sexual conditions were also mistreated. The historian who argues that chlorosis was nothing more than a cultural construction of Victorian family life, that physicians diagnosed the condition simply because they expected to encounter it, and that young women simply learned to manifest the clinical picture of chlorosis must explain the well-documented existence of the disease in young men as well.
Enthusiasm for new historical approaches to disease should not obscure the importance of the final common pathway of social, political, and cultural forces. And that common de-nominator for chlorosis in the nineteenth and early twentieth centuries was an iron deficiency anemia. Social and cultural factors certainly predisposed individuals to chlorosis, but per-sons became patients ultimately because they had red blood cells that were too small and lacked the normal amount of hemoglobin. Poor nutrition – whether from poverty or cultural preferences – certainly contributed. Physicians, with their heavy reliance on bloodletting, even prophylactically in pregnant women, undoubtedly played a part as well. Chlorotic women gave birth to iron-deficient children – “larval chlorotics” they were called. Chlorosis, at bot-tom, was a deficiency disease. Explaining it historically demands an eclectic historiography. The biopsychosocial model emerging as the proper paradigm for health professionals dealing with disease in our time has always operated historically. Ockham’s razor may be useful in logic, but it may slice too narrowly in history. Plethora rather than parsimony more often illuminates the complexities of humanity’s inter-action with society at any given time and place. Chlorosis is a case in point.