Differential diagnosis

The diagnosis is usually apparent from the history and mental state examination. However, physical examination and special investigations are an important part of the assessment, and informants should be interviewed where possible.

The main differential diagnosis is:

• physical disorders:
  • chronic wasting diseases - for example, malignancy, tuberculosis, malabsorption, illicit drug use
  • endocrine disorders - for example, Addison's disease, hyperthyroidism, anterior pituitary insufficiency
• psychiatric disorders:
  • schizophrenia - refusal to eat due to delusion that food is poisoned
  • depression - loss of interest in food or delusions of worthlessness
  • conversion disorders - some patients may present with weight loss and vomiting because of a disgust for food in the absence of a desire for thinness
  • psychogenic vomiting
  • obsessive-compulsive disorder
  • depression (1)
• other causes of amenorrhoea:
  • pregnancy, primary ovarian failure, prolactinomas, polycystic ovary syndrome, uterine problems, and other hypothalamic causes

Reference:

(1) NICE (May 2017). Eating disorders: recognition and treatment