Skin changes in anorexia nervosa can be divided into 4 groups (Gupta et al):
(1) starvation, altered diet and/or malnutrition, including vitamin and endocrine deficiencies
(2) changes associated with self-induced vomiting
(3) effects of drugs being taken (laxatives, purgatives, etc)
(4) self-injuries and other manifestations of psychiatric state
The skin changes tend to be seen when the body mass index (BMI) is <= 16 kg per square meter, reflecting prolonged and advanced disease.
Signs of starvation, altered diet and malnutrition:
(1) xerosis
(2) lanuga-type body hair (fine, downy, pigmented hairs on the abdomen, back and forearms)
(3) telogen effluvium
(4) carotenoderma in patients who eat carrots or other carotenoid-rich vegetables
(5) acne
(6) skin hyperpigmentation
(7) seborrheic dermatitis
(8) acrocyanosis
(9) perniosis
(10) petechiae and purpura (associated with thrombocytopenia)
(11) livedo reticularis
(12) interdigitial intertrigo
(13) paronychia
(14) generalized pruritis
(15) striae distensae
(16) impaired wound healing
(17) prurigo pigmentosa
(18) edema related to protein malnutrition
(19) linear erythema craquele
(20) acral coldness
(21) pellagra
(22) scurvy
(23) acrodermatitis enteropathica
(24) nail fragility
(25) skin fragility
Signs of self-induced vomiting:
(1) knuckle calluses on the dominant hand (Russell's sign), seen in patients who induce vomiting with their finger
(2) dental caries from exposure to gastric acid
