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Overview
Pellagra causes dermatitis, diarrhea, and dementia.
A blood test can check levels.
When to get medical care
Call 911Not an emergency.
Get care todayConfusion, trouble walking, or severe symptoms.
See a doctor soonSymptoms or a low test result.
Causes
Causes include poor diet and alcohol.
OwieClear has pages on 1 condition that can cause rash on sun-exposed skin with diarrhea or confusion, or low niacin (vitamin b3). Each shows how soon to get care.
Common causes
- Niacin (vitamin B3) deficiency (pellagra)See a doctor if it doesn't get better
Low niacin causes pellagra: a dark, rough rash on skin exposed to the sun (like the neck, hands, and face), diarrhea, and confusion or memory problems.
What you can do at home
- Eat foods rich in niacin (vitamin B3): meat, fish, peanuts
- Take supplements only as your provider advises.
Medicines
Supplements or shots, depending on the cause.
At the doctor
Blood tests check levels.
Questions you may be asked
- Diet
- Alcohol
- Medicines
- Digestive problems
The exam
A physical exam.
Tests
- Blood test
Prevention
Eat a varied diet.
- Balanced meals
- Limit alcohol
Check your symptoms
Most symptoms have more than one possible cause. The symptom checker looks at all of your symptoms together, plus your age, and shows how soon to get care.
Sources
Last updated 2026-11-13.