Scratching and fasting: a study of pruritus and anorexia nervosa

Abstract

An association between pruritus and eating disorders has been suggested. This study examined changes in pruritus during weight restoration in a homogeneous group of women with severe anorexia nervosa (n = 19), using a structured 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 restoration. Some 58% of the sample suffered pruritus at low weight in a stable hospital environment. There was a significant association between changes in body mass index and severity of pruritus (P = 0.033), with reduced itching 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 five cases. Where itching was present, it was experienced as severe. We discuss a variety of possible explanations, including psychopathology, endocrine factors, regional blood flow variation, eczema and the role of central opioid and serotonergic activity. We argue that anorexia nervosa should be considered in all patients at low weight presenting with pruritus, and pruritus should be considered to be a physical symptom of anorexia nervosa.

Assessment of anorexia nervosa: an overview of universal issues and contextual challenges

“…For example, ingesting large quantities of salt [83], scratching [84] and blood-letting [85]. How these phenomena fall under the umbrella of wider deliberate self-harm (DSH) phenomena is unclear as DSH has multiple intended functions [86].…”

Salinophagia in anorexia nervosa: Case reports

“…On that basis, we assert that it earns its place in the pantheon of abnormal behaviors related to multi-impulsive eating disorders 5 to which we have previously added blood-letting and cold water baths, 7 and scratch prurigo. 8 From a biochemical perspective, salinophagia has the potential to compound pre-existing renal failure, and anomalous biochemical results should be considered with this possibility in mind, albeit low down the list of differential diagnoses. More commonly, excessive consumption of salt would go unnoticed in the short-term, as renal function is so adaptive to the regulation of salt intake, retaining what it needs and excreting the rest through the kidney.…”

Skin Signs in Anorexia nervosa

“…The pathogenetic mechanism responsible for the development of cutaneous signs in AN has been debated in many studies [9, 10, 11, 12, 13, 14, 15, 16]. A compensatory hypothyroid state, deficiency of vitamins and trace elements, hypervitaminosis A due to an increased intake of carrots and other low-caloric yellow vegetables, a decrease in sebaceous gland activity, cold intolerance, dysfunction of cutaneous immunity, compulsive washing and increased levels of central nervous system opioid peptides seem to play an important role.…”