The main symptom of pellagra is erythema of the skin on the exposed parts in the acute stage, and the chronic pellagra symptom is hypertrophied and blackened skin, accompanied by different degrees of oral damage, and in severe cases, there can be gastrointestinal and mental symptoms. 1. Acute skin symptoms: the manifestation of the face, limb extension and other exposed parts of the erythema, erythema can have blisters and blisters, accompanied by varying degrees of pain or itching. 2. Chronic skin symptoms: rough and thickened skin, hyperpigmentation, some patients will have black scabs on the skin. 3. Oral damage: painful sensation in the mouth, dry and cracked tongue with redness, atrophy of tongue papillae, and whitish vesicles at the corners of the mouth. 4. Gastrointestinal symptoms: most of them are abdominal pain and diarrhea, stools are watery or slurry, and the odor is obvious. 5. Mental symptoms: insomnia, memory loss, and in severe cases, anxiety and depression. Pellagra may also have other causes, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, give targeted treatment or treatment.