Pellagra: Form of malnutrition with niacin deficiency

Pellagra is a form of malnutrition associated with a deficiency of niacin (one of the vitamins of the B complex) or tryptophan (an amino acid: building block of proteins). Diarrhea, skin abnormalities and dementia are characteristic of the disease, but a very broad spectrum of both physical and mental symptoms are possible. The treatment of the disease consists of vitamin supplements. The prognosis of treated patients is excellent, but untreated the disease leads to serious complications and death. The name “pellagra” is derived from the Italian terms “Pelle” (skin) and “Agra” (rough) which refers to the rough skin typical of pellagra.

  • Synonyms pellagra
  • Epidemiology
  • Causes: Niacin deficiency
  • Risk factors of malnutrition
  • Symptoms: Skin (dermatitis), stomach and intestines (diarrhea) and brain (dementia)
  • Diagnosis and examinations
  • Treatment via supplements
  • Disease prognosis is excellent
  • Complications

Synonyms pellagra

Pellagra is also known by these synonyms

  • Asturian rose
  • bread scab
  • Milanese rose
  • Lombard leprosy


The exact incidence of pellagra has not been found in the literature consulted, but the disease is mainly found in developing countries where untreated corn and grain are the main food sources. Pellagra occurs in ethnic populations where the diet is deficient in niacin and/or tryptophan. The disease has no racial or sexual predilection. Pellagra mainly occurs in adults. Pellagra sometimes develops in adolescents and young children if they are exposed to a diet low in niacin and/or tryptophan. Pellagra rarely occurs in infants.

Causes: Niacin deficiency

Pellagra is a rare disease that is mainly found in people who eat almost exclusively maize, for example in parts of Africa. Corn contains low levels of tryptophan as well as niacin in the form of niacytin, which is not biologically available. Many symptoms of pellagra are due solely to niacin deficiency; but some signs are the result of multiple protein deficiencies and a lack of other vitamins.

Alcohol abuse is a risk factor for pellagra / Source: Jarmoluk, Pixabay

Risk factors of malnutrition

In a number of cases, pellagra occurs more quickly, namely:

  • alcohol-dependent patients (alcoholics) who eat little (alcohol abuse)
  • certain medications such as isoniazid, azathioprine
  • chronic diarrhea
  • Hartnup disease: In Hartnup disease, a rare inborn error of metabolism, there is no absorption by the intestine of basic amino acids such as tryptophan. In addition, the patient loses amino acid through the urine.
  • a very low protein diet that a patient follows for kidney disease or that people follow as a fashion trend
  • generalized malabsorption (problems with nutrient absorption) (rare)
  • the carcinoid syndrome (secretion of serotonin in the body) and pheochromocytomas (adrenal medullary tumors with tumor release)
  • Isoniazid therapy: Treatment with isoniazid, a type of antibiotic, may lead to a vitamin B6 deficiency. Vitamin B6 is necessary for the synthesis of nicotinamide from tryptophan.
  • cirrhosis of the liver
  • patients with untreated HIV/AIDS

Symptoms: Skin (dermatitis), stomach and intestines (diarrhea) and brain (dementia)

The classic features include skin inflammation, diarrhea and dementia. However, not all symptoms are always present and the symptoms also vary greatly. The neurological abnormalities are also variable.


Skin inflammation (dermatitis) occurs in areas of the skin exposed to sunlight. Initially, the skin is red and cracked (cracked skin) and skin ulcers develop. Subsequently, the patient develops chronic thickening, dryness and pigmentation of the skin. The lesions are always symmetrical with a clear border between affected and unaffected skin. Usually it is dorsal surface of the hands affected by the skin abnormality. The painful palms are accompanied by itching, tingling, prickling and redness and sometimes loss of strength. Occasionally the skin-related symptoms occur on the neck, forearms, legs, feet and/or the face. Finally, onycholysis (nail detachment) is possible.


Diarrhea (with bleeding) is often a feature, but constipation also occasionally occurs. Other gastrointestinal symptoms (stomach and intestines) include a painful, red, rough tongue, glossitis (inflammation of tongue with smooth and red tongue surface), cheilosis (swelling, cherry-red discoloration, crusting, sometimes with erosions of lip red and corners of the mouth) and stomatitis (inflammation of the mucous membrane in and around the mouth). Recurring mouth infections and nausea are also possible. The lips, tongue and gums are therefore painful and often flake during the disease. Due to the gastrointestinal problems, the patient develops anorexia.


Dementia mainly occurs in chronically ill people. In milder cases, the patient has signs of depression, apathy (lack of motivation in life), insomnia, memory loss, confusion (disorientation in time, place and person) and sometimes other neurological abnormalities. Ataxia (balance and coordination problems), tremor (tremors), seizures, vertigo (dizziness), hearing problems due to the death of the acoustic nerve (hearing nerve) and vision problems due to the death of the optic nerve (optic nerve), double vision (diplopia) and headaches also occur. Hallucinations, acute psychosis (loss of reality with delusions and hallucinations) and anxiety are also possible in patients who exhibit severe symptoms.

Diagnosis and examinations

Physical and diagnostic examination

In endemic areas, diagnosis is made on the basis of clinical characteristics in which the doctor asks the patient about his diet. A blood test or urine test is sometimes necessary to determine the amount of niacin.

Differential diagnosis

Doctors sometimes confuse Pellagra with kwashiorkor, another form of malnutrition in which the patient exhibits a distended abdomen. The following conditions also mimic certain symptoms of the disease:

  • actinic reticuloid (skin disease caused by prolonged exposure to the harmful UV rays of sunlight)
  • atopic eczema (chronic skin disease with dry skin and itchy skin)
  • side effects of medication
  • Hartnup’s disease
  • dermatomycosis corporis
  • photodermatitis
  • lupus erythematosus
  • pemphigus vulgaris (ulcers and blisters of skin & mucous membranes)
  • polymorphic light eruption (skin disease due to sun exposure)
  • porphyria cutanea tarda
  • seborrheic eczema (skin disease with dandruff, flaking and red skin)
  • tinea incognito (fungal infection of the skin due to corticosteroid)
  • toxicoderma
  • sunburn (red, painful skin from sun exposure)

Treatment via supplements

Pellagra is treated with niacin supplements. This greatly improves skin-related symptoms and diarrhea. However, usually a vitamin B complex is needed and the patient has other deficiencies that the doctor must treat. In addition, increasing the protein content of the diet and treating malnutrition and other vitamin deficiencies is essential.

Disease prognosis is excellent

The patient recovers from the condition if the doctor identifies the cause and treats it. Most patients respond excellently to niacin treatment.


Left untreated, pellagra leads to nerve damage, particularly in the brain, resulting in organ failure and death. Occasionally a serious and painful skin inflammation occurs when the ulcers become infected.