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Facts about the skin from DermNet New Zealand Trust. Topic index: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z



Malnutrition including anorexia nervosa

Background

Malnutrition occurs when the supply of nutrients and energy is inadequate to meet the body's requirements.

Worldwide, the most common cause of malnutrition is inadequate food supply. Gastrointestinal infections, particularly parasitic infections, exacerbate this problem. Preschool-aged children in developing countries are most at risk because of their increased protein and energy requirements, greater susceptibility to infection, and exposure to unhygienic conditions. Marasmus and kwashiorkor are two related disorders of severe protein-energy malnutrition that occur mainly in young children from developing countries at the time of weaning.

In developed countries, other causes of malnutrition are more prominent:

Dermatological features of malnutrition

Although malnutrition affects almost every organ in the body, this page focuses on the dermatological features.

Dermatological feature Explanation
Xerosis (dry skin) Due to deficiencies of vitamins and trace elements and possibly disordered thyroid function.
Telogen effluvium Increased shedding of hair on the scalp which can occur following any significant physical or psychological stress. It may also follow a variety of vitamin deficiencies.
Nail abnormalities Nails can become thin and soft and may have fissures (cracks) or ridges. Koilonychia (spoon-shaped nails) may develop due to iron deficiency.
Pale skin Due to iron deficiency.
Glossitis (inflammation of the tongue) Due to severe vitamin B and/or iron deficiency. The small bumps on the surface of the tongue (papillae) may become flattened, causing the tongue to appear smooth.
Angular stomatitis Fissures at the corners of the mouth due to riboflavin and other vitamin deficiencies.
Pruritus (itch) May be caused by xerosis, iron deficiency, or other consequences of malnutrition.
Non-healing wounds and bedsores Due to vitamin C and zinc deficiency.
Acrocyanosis Purple, cold hands and feet associated with circulatory system abnormalities. In rare cases, chilblains can develop.
Acrodermatitis enteropathica Due to zinc deficiency.
Scurvy Due to vitamin C deficiency.
Pellagra Due to niacin deficiency.
Purpura Due to starvation-related bone marrow depression and subsequent reduction in circulating platelets. Also seen in vitamin C deficiency.
Gingivitis May result from severe vitamin D deficiency.

When malnutrition is caused by anorexia nervosa, a number of specific dermatological features are seen:

Dermatological feature Explanation
Lanugo hair Fine, downy, pale hair on the back, abdomen, and forearms. Resolves when normal total body fat is restored.
Carotenaemia Yellowing of the skin due to excessive intake of carrots, other yellow and green vegetables, and citrus fruit. Most evident on the soles and palms.
Self-inflicted wounds Self-inflicted cutting or burning as well as trichotillomania (hair loss due to hair pulling) may be evident.
Pompholyx (blistering hand dermatitis) A rare complication of anorexia nervosa.
Pili torti (twisted hair) Possibly due to malnutrition combined with excessive ingestion of carotene containing fruit and vegetables.

Skin changes associated with anorexia nervosa become more frequent when the body mass index (BMI) falls to 16 kg/m2 or less. Patients with bulimia nervosa (and some patients with anorexia nervosa) engage in uncontrollable binge-eating episodes, followed by purging behaviours such as self-induced vomiting or the use of laxatives. Dermatological features associated with purging behaviours include:

Diagnosis of malnutrition

What is the treatment for malnutrition?

In patients with severe malnutrition, fluid and electrolyte imbalances should be corrected first. Food should be introduced slowly and carefully. Vitamin and mineral supplements may be needed. The skin changes associated with malnutrition generally resolve when nutritional deficiencies are corrected and the patient gains weight.

Related information

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Author: Dr Marie Hartley, Staff Writer.

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