Pellagra is a disease caused by a severe deficiency in the vitamin B3, known as niacin, and/or tryptophan, an essential amino acid that helps produce niacin in the body. We typically get our crucial sources of niacin and tryptophan through a balanced diet. Niacin is very important as it helps our cells and organs function properly, and a lack of this vitamin can lead to symptoms throughout the body - the skin, mouth, gastrointestinal tract, and the brain and nervous system. If left untreated, pellagra can lead to death.¹ 

Therefore, awareness of the disease’s treatments and preventative measures is crucial to ensure this does not happen. This article will outline the development of pellagra, as well as the current treatments and prevention methods available to tackle the disease.  

Types of pellagra

There are two main types of pellagra, which have different causes. 

Primary pellagra

Primary pellagra is caused by the lack of niacin and/or tryptophan in one’s diet. This type of pellagra is known as a malnutrition disease - specifically undernutrition of a micronutrient. Primary pellagra typically occurs in developing countries, in impoverished populations where they do not eat a balanced diet due to a limit in the variety of food available. In particular, primary pellagra is prevalent in countries where corn (maize) is a main food source. This is because our body cannot process and digest the form of niacin found within corn. 

Secondary pellagra

Secondary pellagra occurs when the body is unable to absorb the niacin and tryptophan from the food we eat. This type of pellagra typically occurs in developed countries, where people do eat the right amount of niacin and tryptophan thanks to a balanced diet, however, due to underlying health conditions, they cannot absorb and use the niacin they are eating. 

Examples of health conditions which can lead to secondary pellagra include:

Gastrointestinal diseases

Your gastrointestinal tract is in charge of absorbing nutrients such as niacin and tryptophan, allowing cells to use them. When someone suffers from a disease involving this tract, malabsorption can occur, making it difficult to absorb nutrients from food. An example of a gastrointestinal disease that can lead to pellagra is Crohn’s disease.² 

Bariatric surgery

This type of surgery, which is designed to make the stomach smaller, can negatively affect the gastrointestinal system, by damaging the soft tissue that lines it. This in turn can lead to malabsorption and the development of pellagra.³

Heavy use of alcohol

When someone excessively drinks alcohol, this can damage their organs, including the gastrointestinal system. This means that this system cannot absorb niacin and tryptophan properly, potentially resulting in pellagra.⁴ 

Hartnup disease

This is a genetic disorder that prevents the body from absorbing amino acids such as tryptophan. Without absorption of this essential amino acid, production of niacin cannot occur, potentially resulting in pellagra.⁵  

Iron deficiency

Iron is used to help convert tryptophan into niacin, hence deficiencies in this mineral could lead to pellagra.⁶ 

Carcinoid syndrome

This disease consists of tumour cells actively stopping tryptophan from producing niacin, in turn leading to the potential development of pellagra.⁷ 

Drugs

Some drugs, such as antispasmodic and chemotherapy medications used to treat conditions such as irritable bowel syndrome and cancer, can in turn affect how the gastrointestinal tract processes niacin. These disruptions can lead to pellagra. 

What is niacin and why is it important to us?

Niacin is important to us as it helps convert the food we eat into energy that our cells use to function. In a healthy body, the niacin and tryptophan we eat is absorbed through the small intestine and into our body’s tissues and organs. Once absorbed, the tryptophan is converted into niacin. All the niacin is then further converted into nicotinamide adenine dinucleotide (NAD).¹ NAD is a coenzyme, which is a type of substance which helps enzymes in speeding up important chemical reactions in the body. Over 400 types of enzymes rely on NAD to function. The essential chemical reactions which NAD helps speed up include those which convert potential energy from food we ingest into energy which is accessible to our cells to use (this energy being known as adenosine triphosphate, ATP). This energy is essential in keeping our cells and organ systems functioning properly.⁸   

How does niacin deficiency affect the body? 

Niacin and NAD are crucial in giving essential energy to our cells to help them function. when there is a lack of niacin, such as in pellagra patients, symptoms typically show in the organ systems that require the highest amount of energy to function properly. These body systems include the skin, the gastrointestinal tract, and the brain.⁹ 

Classic Pellagra Symptoms: the “3 Ds”

Classic symptoms of both primary and secondary pellagra are described as the “3 Ds”: dermatitis, diarrhoea, and dementia. Sometimes a fourth “D” is added, which stands for death. This can occur in pellagra patients if no treatment is given for several years after the first symptoms show.⁹ 

Dermatitis

Pellagra leads to dermatitis on the sun-exposed areas of the body (for example the face, neck, arms, legs, and hands). Since the skin cells do not have any energy, due to the lack of niacin, they become more sensitive to sunlight, and hence itchy, red, painful rashes which resemble sunburn will appear. These rashes can then become rough and scaly plaques. A specific type of dermatitis unique to pellagra is Casal’s collar, a plaque that forms around your neck.⁹ 

Diarrhoea

Without energy, the cells of the lining of the gastrointestinal tract will fail to digest food properly, leading to chronic diarrhoea. In addition, a lack of a functioning gastrointestinal lining will result in other symptoms such as chronic inflammation and irritation of the tract, stomach pain, mouth sores, and a swollen, red tongue.⁹

Dementia

The lack of energy in cells will affect the brain and the nervous system as well. Early signs of pellagra-related dementia include having difficulties in concentrating and lacking enthusiasm and energy. As the disease progresses, patients can also experience confusion and delusions. In very severe cases, where pellagra has been left untreated for a long time, permanent neurological damage can also occur, leading to coordination problems, numbness in the limbs, and muscle tremors.⁹  

How to diagnose pellagra

Both primary and secondary pellagra are diagnosed in the same manner, as both types show similar symptoms. You are suspected to have pellagra if you exhibit the “3 Ds''. You will then visit your doctor who will examine your medical history and diet to assess the cause behind the pellagra. To confirm the disease, you will do a urine test. If you have pellagra, there will be significantly low levels of certain chemicals, namely N-methylnicotinamide and pyridone, in your urine, indicating a niacin deficiency in your body.

How to treat pellagra

As pellagra is a disease caused by a deficiency of niacin, the best way to treat it is by replacing this missing vitamin. The World Health Organisation (WHO) recommends 300g of nicotinamide, an active form of niacin that can be easily digested. This treatment should be given orally daily for 3-4 weeks. 

Other supplements that could be used alongside nicotinamide are general vitamin B supplements. This is because pellagra patients are likely to also suffer from deficiencies in other types of vitamin B, so, these supplements will replenish their overall vitamin B levels. 

Alongside these supplements, additional ways to help treat pellagra is by eating good food sources of niacin and tryptophan which we can easily digest. Examples of these foods include:

• Meat/fish: Such as salmon, tuna, beef liver, red meat and chicken
• Legumes: Such as peanuts and groundnuts
• Cereals: Such as bread and rice 
• Green leafy vegetables

To treat dermatitis symptoms, moisturisers (known as topical emollients) can be applied to the skin to help relieve them. 

If yousuffer from secondary pellagra, then further specific treatment will be needed to treat the pre-existing health condition that caused the pellagra. 

Side effects from the treatment

There are very few side effects from taking the supplements described above as part of the pellagra treatment plan. If the prescribed dosage is taken, there should be no side effects. If a patient significantly overdoses on supplements, then they may feel the following temporary side effects:

• Red rashes on the face (flushing)
• Itching
• Bloating and indigestion
• Headaches
• Feeling dizzy 

Prognosis

With nicotinamide supplements, most symptoms of pellagra patients will improve within a few days of starting treatment. The first symptoms to heal tend to be gastrointestinal and skin-related ones - within the first two weeks. If you have neurological deficits, these may take longer to heal. Some nerve damage may be irreversible if the pellagra is left untreated for too long.⁹ 

With regard to secondary pellagra, the prognosis will depend on how easy it is to treat the underlying condition.⁹

Prevention strategies

There are various ways that WHO has explored and suggested as methods to prevent both primary and secondary pellagra. 

Supplementation of niacin tablets and a balanced diet

WHO indicates that a daily oral intake of 15-20mg of niacin can prevent pellagra from developing in all age groups. This can be done either via niacin tablets, vitamin B tablets, or by consuming a balanced diet containing rich sources of niacin (as mentioned above). 

Fortification of food

For decades, developed countries have added vitamin B, such as niacin, to white flour and cereal products (such as corn, pasta, bread, white rice, and breakfast cereals) through a process known as fortification. This practice has increased the intake of essential vitamin Bs in these populations. These fortification policies have helped reduce the incidence of pellagra, and prevented many others from suffering from this disease.¹⁰  

Provision of food rations containing niacin-rich foods 

Food rations (packages of food) can be delivered to poor communities that suffer the most from pellagra outbreaks and whose diet mainly consists of corn. These packages can contain niacin-rich foods, such as different types of meat and fish, fortified cereal products, and legumes. 

Treating maize to make its niacin content available

There are strategies to make the niacin in maize easily digestible by treating the corn with a mild alkali. For instance, it is tradition in Central America to first treat maize in the alkaline lime-water, to allow the niacin to be easily digested. This method has been shown to protect this population from pellagra.¹¹ 

Education and awareness

Raising awareness about pellagra and their treatments in communities where the disease is prevalent is an effective way to prevent the disease from occurring. Alongside this education, encouragements can be made to help these communities find ways to further prevent pellagra. For instance, promoting the cultivation of home gardens and keeping livestock will diversify their diet and provide them with niacin-rich food sources.

Summary

Pellagra is a malnutrition disease caused by a deficiency in the essential vitamin B3, called niacin, and its precursor tryptophan. Niacin is crucial to us, as it provides our cells with the energy they need to help our body systems function properly. Without niacin, our whole body can be affected due to a lack of energy. The main organ systems affected by pellagra include the skin, the gastrointestinal tract, and the nervous system. Symptoms associated with pellagra are dermatitis on sun-exposed parts of the body, diarrhoea, and dementia. If left untreated for too long, pellagra can result in death.

The most efficient treatment plan to cure pellagra includes taking nicotinamide (niacin supplements) and supporting this treatment with vitamin B supplements and a diet consisting of niacin-rich foods. With such treatments, pellagra symptoms can be quickly reversed. There are also various ways to prevent pellagra, such as daily intake of niacin via supplements and a balanced diet, fortifying and treating foods with niacin, and providing niacin-rich food rations to poor communities. Hence, pellagra can be easily preventable, and when found early can be easily treatable, highlighting the importance of spreading awareness about this disease.