The Blame-X syndrome: problems and lessons in nosology, spectrum, and etiology.

Symptoms of a functional somatic syndrome have been noted in individual persons and groups for more than a century. Often associated with war, the syndrome has received diverse names and many proposed but unproved etiologies, including exposure to trauma, stress, chronic infection, psychosomatic, chemical, or environmental causes. In recent years, when attributed to agent X, the syndrome could be called the Blame-X syndrome. The clinical, legal, and other problems associated with the syndrome are a reflection of nosologic difficulties in identifying and choosing titles for apparently "new" ailments. The difficulties arise from the complex overlap of symptoms, diseases, and laboratory abnormalities found with modern technology, and from the frequent abandonment of pathophysiologic demands for appropriate correlation of symptoms and objective abnormalities. An important principle in naming apparently new ailments is to avoid etiologic titles until the etiologic agent has been suitably demonstrated. A premature causal name can impair a patient's recovery from the syndrome, and impede research that might find the true cause.