​Dermatology - Pellagra

​Dermatology - Pellagra 
A diet low in tryptophan, niacin, or both can cause pellagra. A diet high in maize is typically the culprit.
The three Ds of pellagra are dementia, diarrhea, and dermatitis. Pressure and solar exposure determine changes in the skin.
Damage
On the dorsa of the hands, neck, and face, asymmetric itching and smarting erythema is followed by breakouts of vesicles and bullae, which may burst and crust to form scaly lesions. Subsequently, the skin develops fissures, cracks, and a clear separation from normal skin. It also becomes rough, lichenified, and indurated, with dark scales and crusts covering it.
The finding of lower urine metabolite levels confirms the diagnosis.

Complete resolution is achieved by taking 100–300 mg of niacinamide orally together with other B vitamins.