Cause
Pellagra is caused by a cellular deficiency of niacin.
| Primary due to inadequate niacin and/or its precursors, the essential amino-acid tryptophan intake |
| Nutritional: |
| Reduced intake |
| Maize and sorghum (jowar) diet |
| Secondary due to defective absorption or processing of niacin |
| Malabsorption: |
| Inflammatory bowel disease- Crohn's disease |
| Major gastro-intestinal surgeries |
| Jejuno-ileitis |
| Impaired absorption of tryptophan and niacin by gastric mucosa |
| Chronic alcoholism |
| Primary Sjögren's syndrome |
| Infection: |
| HIV |
| Drug induced: |
| Isoniazid, Ethionamide, 6-mercaptopurine, 5-fluorouracil, pyrazinamide, phenytoin, azathioprine, phenobarbitals, hydantoins, l and chloramphenicol |