Primary pellagra is now seen in individuals with alcoholism, those who participate in “fad” diets, and those with primary or secondary malabsorption states. The malnourished state associated with pellagra results in death if untreated.
Pellagra, which is caused by a deficiency of NIACIN and TRYPTOPHAN, the precursor of niacin, is a rare disease in developed countries except where regular consumption of alcohol is a major risk factor due to subsequent malnutrition and lack of B vitamins.
Although pellagra involves treatable dementia and psychosis, it is often under-diagnosed, especially in developed countries.
Because of the large range of organs and tissues impacted by niacin deficiency, the clinical expression of pellagra is diverse. Pellagra is classically defined by “the 3 Ds” (ie, diarrhea, dermatitis, and dementia.)
Mucosal inflammation and atrophy involves most of the GI tract. Evidence of glossitis(inflammation of the tongue) and atrophy of the papillae of the tongue are characteristic findings, along with gastritis and subsequent gastric mucosal atrophy. Acute inflammation of the small intestine and colon are also commonly noted.
Almost universally, GI symptoms precede the skin manifestations.
Skin lesions are usually sharply demarcated and occur in areas more prone to sun exposure. Histopathologic changes include vascular dilatation, proliferation of endothelial lining, perivascular lymphocytic infiltration, and hyperkeratinization and subsequent atrophy of the epidermis.
Microscopic changes in the presence of a grossly normal nervous system can be found in the brain, spinal cord, and peripheral nerves. Findings include central chromatolysis of neurons, patchy demyelinization, and degeneration of the various affected parts of the nervous system. Pellagra is often an evolving process, which, if untreated, can lead to progressive deterioration and death (the fourth “D”) over a period of years.
- Early systemic effects of the disease include malaise, apathy, weakness, and lassitude.
- GI involvement leads to a malabsorptive state and subsequent failure to thrive. The patient can appear to have irritable bowel syndrome.
- Dermatitis tends to be painful during the acute phase and eventually becomes disfiguring.
- Neurological manifestations include anxiety, depression, delusions, hallucinations, headaches, insomnia, and stupor.
- Besides presenting as the nonalcoholic pellagra, acute pellagraphic encephalopathy can present with ataxia and myoclonus as the chief symptoms.
Public awareness campaigns, agriculture diversification, change of food habits, and food fortification with nicotinic acid were all responsible for the eradication of pellagra in the South. The recommendation of the Food and Nutrition Board regarding the enrichment of bread and flour with thiamine, niacin, and iron was endorsed by the members of the baking and milling industries in 1941. Soon the food fortification program played a crucial role in eliminating pellagra. The consumption of enriched flour and bread ensured that the dietary intake of niacin and thiamine was adequate, thus ensuring the prevention of pellagra and beriberi.
Pellagra was truly conquered in the American South during the Second World War.
Paradoxically, there was relative prosperity during the war. The economy improved, there were more jobs, and almost everyone had an income. The wartime rationing also made the people conscious of eating high quality food. By 1945, pellagra had become extinct in the South, and the pellagra producing 3-M diet of southerners had become a relic of the past.