{"id":4422608,"date":"2025-01-12T07:48:27","date_gmt":"2025-01-12T13:48:27","guid":{"rendered":"https:\/\/myendoconsult.com\/learn\/topics\/pellagra\/"},"modified":"2025-01-12T07:58:09","modified_gmt":"2025-01-12T13:58:09","slug":"pellagra","status":"publish","type":"oen_topic","link":"https:\/\/myendoconsult.com\/learn\/topics\/pellagra\/","title":{"rendered":"Pellagra"},"content":{"rendered":"\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">OVERVIEW OF B3 DEFICIENCY<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Vitamin B3 (niacin)<\/strong>: Exists primarily as <strong>nicotinic acid<\/strong> and <strong>nicotinamide<\/strong>.<\/li>\n\n\n\n<li><strong>Key dietary sources<\/strong>:\n<ul class=\"wp-block-list\">\n<li>Meats (especially liver)<\/li>\n\n\n\n<li>Yeasts<\/li>\n\n\n\n<li>Whole-grain cereals<\/li>\n\n\n\n<li>Legumes<\/li>\n\n\n\n<li>Seeds<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Geographic distribution<\/strong>: Historically linked to diets based heavily on maize\/corn; still seen in parts of India, China, and Africa.<\/li>\n\n\n\n<li><strong>Causes in developed countries<\/strong>:\n<ul class=\"wp-block-list\">\n<li>Gastrointestinal malabsorptive disorders<\/li>\n\n\n\n<li>Anorexia nervosa<\/li>\n\n\n\n<li>Alcoholism<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">BIOCHEMICAL ROLE<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Niacin<\/strong> (nicotinic acid &amp; nicotinamide) is converted (along with <strong>tryptophan<\/strong>) to form:\n<ul class=\"wp-block-list\">\n<li><strong>NAD<\/strong> (nicotinamide adenine dinucleotide)<\/li>\n\n\n\n<li><strong>NADP<\/strong> (nicotinamide adenine dinucleotide phosphate)<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>NAD &amp; NADP<\/strong>:\n<ul class=\"wp-block-list\">\n<li>Vital in <strong>redox reactions<\/strong> and <strong>hydrogen transport<\/strong><\/li>\n\n\n\n<li>Essential for <strong>synthesis and metabolism of carbohydrates, fats, and proteins<\/strong><\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Absorption<\/strong>: Occurs in <strong>jejunum and ileum<\/strong>.<\/li>\n\n\n\n<li><strong>Tissue uptake<\/strong>: Rapidly taken up by <strong>liver, kidney, RBCs<\/strong>.<\/li>\n\n\n\n<li><strong>Storage\/Use<\/strong>: Intracellularly converted to NAD\/NADP; stored mostly in <strong>liver &amp; muscle<\/strong> (high metabolic activity tissues).<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">PELLAGRA<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Definition<\/strong>: A nutritional deficiency disorder caused by <strong>insufficient intake of niacin<\/strong>.<\/li>\n\n\n\n<li><strong>Name origin<\/strong>: \u201cRaw skin,\u201d first described in 1735 by Cas\u00e1l in Spanish peasants subsisting on maize-based diets.<\/li>\n\n\n\n<li><strong>Classic triad<\/strong>: <strong>Dermatitis<\/strong>, <strong>diarrhea<\/strong>, <strong>dementia<\/strong> (\u201c3 D\u2019s\u201d).<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Clinical Features<\/h3>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Dermatitis<\/strong>:\n<ul class=\"wp-block-list\">\n<li><strong>Photosensitivity<\/strong> with symmetric lesions; sharp borders between affected\/unaffected skin.<\/li>\n\n\n\n<li>Common on <strong>extensor surfaces<\/strong> (hands, arms, feet) \u2192 \u201cglove-and-stocking\u201d distribution.<\/li>\n\n\n\n<li><strong>Cas\u00e1l necklace<\/strong>: circumferential lesion around neck.<\/li>\n\n\n\n<li>Facial lesions may appear over the alae of the nose and forehead.<\/li>\n\n\n\n<li>Intertriginous and moist areas also commonly affected.<\/li>\n\n\n\n<li>Lesions evolve from sunburn-like erythema \u2192 reddish-brown, rough, scaly patches \u2192 central desquamation revealing thickened, red skin.<\/li>\n\n\n\n<li>Chronic changes: skin may remain roughened and pigmented.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Stomatitis &amp; GI Involvement<\/strong>:\n<ul class=\"wp-block-list\">\n<li>Sore mouth, angular cheilitis.<\/li>\n\n\n\n<li>Indigestion, bright red tongue with flattened papillae.<\/li>\n\n\n\n<li><strong>Diarrhea<\/strong> (watery; may contain blood or pus).<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Neurologic\/Psychiatric<\/strong>:\n<ul class=\"wp-block-list\">\n<li>Can present with encephalopathy mimicking mental illness (e.g., <strong>depression, suicidal tendencies<\/strong>).<\/li>\n\n\n\n<li>Anxiety, disorientation, hallucinations, confusion, delirium, dementia, and coma.<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">DIAGNOSIS<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Clinical recognition<\/strong> of dermatitis, diarrhea, dementia is key.<\/li>\n\n\n\n<li><strong>Lab confirmation<\/strong>: Blood niacin concentration (typical normal range is approximately 0.50\u20138.45 \u03bcg\/mL in adults).<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">PREVENTION<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Recommended Daily Allowance (RDA)<\/strong>:\n<ul class=\"wp-block-list\">\n<li>~16 niacin equivalents\/day (men)<\/li>\n\n\n\n<li>~14 niacin equivalents\/day (women)<\/li>\n\n\n\n<li>~18 niacin equivalents\/day during pregnancy, 17 niacin equivalents\/day during lactation<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li>One niacin equivalent = 1 mg niacin or ~6 mg tryptophan.<\/li>\n\n\n\n<li><strong>High-risk groups<\/strong>: Individuals who have had malabsorptive procedures or are on renal dialysis may need extra supplementation.<\/li>\n\n\n\n<li><strong>Dietary advice<\/strong>: A balanced diet that includes meat, yeasts, whole grains, legumes, seeds usually provides sufficient niacin.<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>OVERVIEW OF B3 DEFICIENCY BIOCHEMICAL ROLE PELLAGRA Clinical Features DIAGNOSIS PREVENTION<\/p>\n","protected":false},"featured_media":0,"template":"","oen_topic_chapter":[689],"class_list":["post-4422608","oen_topic","type-oen_topic","status-publish","hentry","oen_topic_chapter-obesity-medicine","post-wrapper","thrv_wrapper"],"_links":{"self":[{"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/oen_topic\/4422608","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/oen_topic"}],"about":[{"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/types\/oen_topic"}],"version-history":[{"count":4,"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/oen_topic\/4422608\/revisions"}],"predecessor-version":[{"id":4422613,"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/oen_topic\/4422608\/revisions\/4422613"}],"wp:attachment":[{"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/media?parent=4422608"}],"wp:term":[{"taxonomy":"oen_topic_chapter","embeddable":true,"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/oen_topic_chapter?post=4422608"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}