Makindo Medical Notes.com

The four Ds of pellagra are dermatitis, diarrhoea, and dementia leading to death. Pellagra was considered to be an infectious disease until the early 20th century

About

• Thiamine was the first B vitamin to be identified
• Inadequate dietary intake of niacin and/or tryptophan
• Pellagra is from the Italian pelle agra, sharp [i.e., rough] skin.

Causes

• People eating corn/maize-based diets
• Alcoholics, Anorexia
• Adrenal phaeochromocytoma
• Gastrointestinal disease
• Isoniazid inhibits the conversion of tryptophan to niacin

Aetiology

• Used to make NAD and NADP from precursors nicotinic acid, nicotinamide and tryptophan
• Niacin is vital to oxidation of all living cells
• There may be some liver storage
• Lowers LDL and VLDL cholesterol

Types

• Primary pellagra is said to occur due to dietary deficiency of niacin or tryptophan.
• Secondary pellagra is due to processes interfering with metabolism or absorption of niacin or tryptophan

Pellagra may occur as a consequence of isoniazid therapy (isoniazid inhibits the conversion of tryptophan to niacin

Clinical

• Glossitis and a pigmented, scaling rash that may be particularly noticeable in sun exposed areas.
• Anorexia, irritability, abdominal pain and vomiting, and glossitis.
• Vaginitis and oesophagitis may also occur.
• Dermatitis, diarrhea, and dementia leading to
• Rash called casal's necklace round the neck; it is seen in advanced cases. death.
• Progressive dementia and death

Investigations

• Microcytic hypochromic anaemia
• Hyperhomocysteinemia
• Serum niacin levels are low

Management

• Start Oral Nicotinamide and any other nutritionalsupplementation. Response is often dramatic in weeks .
• A longer-term solution for the complete eradication of pellagra may be the fortification of maize or bean flour with nicotinamide.

References

• PELLAGRA and its prevention and control in major emergencies