Scratching and fasting: a study of pruritus and anorexia nervosa

An association between pruritus and eating disorders has been suggested, Th is study examined changes in pruritus during weight restoration in a homoge neous group of women with severe anorexia nervosa (n=19), using a structure d questionnaire, visual analogue scale, clinical examination and a range of serological markers. We demonstrated that itching is a clinical feature of anorexia nervosa, associated with low weight and resolving on weight resto ration. Some 58% of the sample suffered pruritus at low weight in a stable hospital environment. There was a significant association between changes i n body mass index and severity of pruritus (P = 0.033), with reduced itchin g on weight restoration. Pruritus occurred in the absence of abnormalities in thyroid, renal and hepatic function, serum androgens, oedema, dermatoses or compulsive washing, Scratching was manifest as 'scratch prurigo' in fiv e cases. Where itching was present, it was experienced as severe. We discus s a variety of possible explanations, including psychopathology, endocrine factors, regional blood now variation, eczema and the role of central opioi d and serotonergic activity. We argue that anorexia nervosa should be consi dered in all patients at low weight presenting with pruritus, and pruritus should be considered to be a physical symptom of anorexia nervosa.