INTRODUCTION As LONG AGO as 1842, the distinguished dermatologist Erasmus Wilson [I] when listing the many local and constitutional causes of eczema, included among the latter “affections of the nervous system, as mental emotions, particularly of the depressing kind”. Today there is widespread acceptance among dermatologists that psychological factors can be important in precipitating or perpetuating the eczematous dermatoses [2], but the problems implicit in Wilson’s short statement are far from solved, and the literature presents a confused picture. This is because of the methodological laxness of many studies, the variability with which distinctions have been made between the different sub-types of eczema, and between vulnerable personality, psychiatric illness, less clear-cut stress reactions, and the effects of chronic disease. Although most psychiatric studies agree that eczema patients have vulnerable personalities, they are described very variously [3-131 as immature, insecure, sadomasochistic, dependent, or hiding dependence under a layer of resentment, exhibitionism, ambition or conscientiousness. The incidence of psychiatric morbidity in eczema patients has also been very variously assessed [5, 15-171, particularly with regard to the amount of overt depression and the general level of neuroticism. While no single or specific eczema personality can be discerned, there is one consistent theme in the literature, that of inhibition or suppression of aggressive impulses, particularly those springing from frustated dependency needs, and often leading to exacerbations of the eczema [S, 6, 12, 18-231. Whatever the specific factors leading to eczema rather than another psychosomatic disorder, the crucial point is that this inhibition or suppression does not lead to a purely psychological disturbance, e.g. an anxiety or depressive reaction, or to disturbed behaviour. Instead, in Groen’s sense [24] eczema is substituted though with a degree of completeness that varies from case to case. It seems likely that both personality and situational factors can influence the substitution, and that these need to be explored if we are to understand some of the apparent discrepancies in the literature. Many important questions are provoked by Erasmus Wilson’s statement. What is the relation between local and psychological factors? Are the ‘affections of the nervous system’ recognizable as personality disorders or psychiatric illnesses? How common is morbid depression ? Is the eczema a concomitant of or substitute for ‘mental emotion’? If either, what are the determining factors? An opportunity to investigate some of these problems occurred during the course of a controlled trial of psychiatric treatment in the management of eczema, carried out at the Middlesex Hospital in association with Sir Denis Hill and Dr. F. R. Bettley.