ABSTRACT
The chronic fatigue syndrome comprises one of the most challenging issues in contemporary medicine. The condition remains distressing for patients and perplexing to medical science. Clinicians face a management path which has no “gold standard” of investigational mileposts; and are locked into a progression where the extremes of either undertreatment or over-investigation may lead to iatrogenic disaster.
The themes of investigation, diagnosis and management of patients with the chronic fatigue syndrome remain controversial. This condition joins in historical perspective a series of other diseases such as pink disease, post-traumatic stress disorder (by a variety of names), the Royal Free disease, Q Fever, Ross River disease and chronic ciguatera-all of which have occupied windows of historical time in the twentieth century during which their genesis remained an enigma. In some cases, they still do. New and puzzling diseases will undoubtedly arise in the future. Both patients and medical science are best served if the formal discipline of differential diagnosis is followed unswervingly under these circumstances or “new” diseases. The rigour of this discipline-the rank listing of formal possibilities after the clinical history and objective signs have been elicited-forms the pivot of best-practice contemporary medicine. An example of its power is no more dramatically illustrated by the example of a “new” enigmatic disease, chronic ci-guatera, which “reappeared” in the 1950s. Ciguatoxins are some of the most potent biological substances known. Their neurotropic effects produce a protean array of symptoms which are distressing in the acute-phase syndrome and which are enervating throughout the often-prolonged progression of convalescence. It is now appreciated that such effects are due to sodium channel activation and subsequent dysfunction at the receptor sites on the cell surface of all excitable tissues.
Dr. A. Melvin Ramsay, the Honorary Consultant Physician in Infectious Diseases at the Royal Free Hospital in London, was at the clinical epicentre of the presentation of another new disease in July 1955. His approach to its diagnosis, in the best traditions of differential diagnosis, is an exemplar of the objective response to the appearance of a new or enigmatic disease; and especially to that type in which experience has not generated sufficient case familiarity to define syndrome barriers or to establish pathogenesis. Under such conditions, the correct diagnostic paradigm is to follow the discipline of differential diagnosis, an evolved phenomenon of the last one hundred years of medicine. This paper traces the evolution of the process of differential diagnosis, in the perspective of the enigma of chronic fatigue, which remains an unmet challenge today.