Pellagra
A niacin deficiency disease causing dermatitis, dementia, and death.
Pellagra is a disease caused by a lack of the vitamin niacin (vitamin B3). Its classic symptoms are diarrhea, dermatitis, dementia, and death (the four Ds). The disease occurs most commonly in the developing world, often as a disease of poverty associated with malnutrition, specifically sub-Saharan Africa.
- type
- Disease
- cause
- Niacin (vitamin B3) deficiency
- symptoms
- Inflamed skin, diarrhea, dementia, sores in mouth
- treatment
- Nicotinic acid or nicotinamide supplementation
- primary type
- Due to diet lacking niacin and tryptophan
- secondary type
- Due to poor ability to use niacin (e.g., alcoholism, Hartnup disease)
Lore & Background
He explained that the disease causes dermatitis in exposed skin areas such as hands, feet, and neck and that the origin of the disease is poor diet and atmospheric influences.
Reader's Guide
Pellagra is significant as a classic example of a micronutrient deficiency disease linked to poverty and diet. Its history illustrates the importance of food preparation: Native American cultivators who first domesticated corn prepared it by nixtamalization, which makes niacin nutritionally available and prevents pellagra. When maize was cultivated worldwide and eaten as a staple without nixtamalization, pellagra became common. The disease was once common in the poorer states of the U.S. South, where its cyclical appearance in spring after meat-heavy winter diets led to it being known as 'spring sickness'. Without treatment, pellagra can kill within four or five years. Treatment with nicotinamide typically brings improvements within a few days. The disease remains a public health concern in developing regions, particularly sub-Saharan Africa, and among displaced populations dependent on food aid.
Did You Know?
- The word 'pellagra' comes from Lombardic; 'pell' arises from Latin pellis meaning 'skin', while '-agra' may derive from Lombardic agra or the Latinate suffix for maladies.
- Pellagra can be caused by excess leucine, which inhibits quinolinate phosphoribosyl transferase and the formation of nicotinic acid to nicotinamide mononucleotide.
- In the 2000s, pellagra outbreaks occurred in countries such as Angola, Zimbabwe, and Nepal.
- Pellagra was common among prisoners of Soviet labor camps (the gulags).
Frequently Asked Questions
What is Pellagra?
Pellagra is a nutritional deficiency disease that arises when the body does not receive enough niacin (vitamin B3). It is classified as a malnutrition-related illness rather than an infectious one.
What causes Pellagra?
The primary trigger is a diet insufficient in niacin and tryptophan, the amino acid the body can convert into usable niacin. Secondary causes include conditions that impair niacin utilization, such as chronic alcoholism or Hartnup disease.
What are the classic symptoms of Pellagra?
The disease is well known for its "four Ds": dermatitis (inflamed, scaly skin), diarrhea, dementia (progressive confusion and cognitive decline), and ultimately death if untreated. Patients may also develop painful sores inside the mouth.
How is Pellagra treated?
Treatment is straightforward: supplementing the patient with nicotinic acid or nicotinamide to restore adequate niacin levels. Because the condition is purely nutritional, symptoms generally reverse once proper supplementation is begun.
Where is Pellagra most common today?
It predominantly affects impoverished populations in the developing world, especially in sub-Saharan Africa, where it is tightly linked to food insecurity. In high-income countries it is now rare, typically surfacing only in individuals with severe alcoholism or specific metabolic disorders.
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