What is pellagra?
Pellagra is a disease characterised by diarrhoea, dermatitis and dementia. If left untreated, death is the usual outcome. It occurs as a result of niacin (vitamin B-3) deficiency. Niacin is required for most cellular processes. Since tryptophan in the diet can be converted to niacin in the body, both of these need to be deficient for pellagra to develop.
What causes pellagra?
Pellagra is caused by a deficiency in niacin. This can occur in 2 ways:
- Primary pellagra results from inadequate niacin and/or tryptophan in the diet (mainly in developing countries or poverty stricken areas)
- Secondary pellagra occurs when there is enough niacin in the diet but something prevents its absorption and processing. Causes of secondary pellagra include:
What are the signs and symptoms of pellagra?
The classical triad of symptoms are diarrhoea, dermatitis and dementia.
What treatment is available?
Pellagra can be effectively cured with intravenous or oral niacin or nicotinamide. Adequate doses to treat secondary pellagra are quite hard to get hold of in New Zealand!
An improvement in primary pellagra should be seen within two days of commencing treatment. A high protein diet supplemented with B-group vitamins is needed for complete recovery. Secondary pellagra may be harder to treat in view of its possible causes.
Book: Textbook of Dermatology. Ed Rook A, Wilkinson DS, Ebling FJB, Champion RH, Burton JL. Fourth edition. Blackwell Scientific Publications.