II. Causes

  1. Primary Pellagra
    1. Inadequate Niacin or Tryptophan intake
  2. Secondary Pellagra (conditions interfering with absorption or metabolism or tryptophan or Niacin)
    1. Anorexia Nervosa
    2. Chronic Diarrhea
    3. Chronic Alcoholism
    4. Chronic colitis or ileitis
    5. Cirrhosis
    6. Hartnup Disease
    7. HIV Infection
    8. Malignant Carcinoid Tumor
    9. Medications
      1. Isoniazid (Niacin analog)
      2. Pyrazinamide
      3. Phenobarbitone
      4. 6-Mercaptopurine
      5. Fluorouracil
      6. Phenytoin
      7. Azathioprine

III. Pathophysiology

  1. Results in decreased NAD production

IV. Symptoms

V. Signs: Classic Triad

  1. Diarrhea
  2. Dermatitis
  3. Dementia

VI. Signs: Dermatitis

  1. May be absent despite neurologic changes (esp. chronic Alcoholism)
  2. Early (wet Pellagra)
    1. Sunburn-like skin dermatitis (erythema in sun exposed areas progresses to overlying vessicles or bullae)
  3. Later
    1. Scaly, symmetric red-brown Skin Discoloration involving face, neck (casal necklace), extensor hands/Forearms
    2. Dull red discoloration of nose with yellow Scaling
  4. Other skin and mucosal findings
    1. Alopecia
    2. Beefy red, smooth Glossitis
    3. Edema

VII. Signs: Neurologic changes

VIII. Labs

  1. Avoid lab testing (treat empirically based on symptoms, signs)
  2. Serum Levels (e.g. Niacin, tryptophan) are typically unreliable
  3. Urine metabolites (e.g. N-methylnicotinamide, 2-pyridone) are unreliable

IX. Management

  1. Precautions
    1. Replacement of other B Vitamins without B3 replacement may exacerbate pellegra encepholopathy
  2. Vitamin B3 replacement
    1. Observe for rapid improvement in symptoms after starting replacement
    2. Initial
      1. Niacinamide 50 mg orally every 6 hours until major signs and symptoms resolve
    3. Next
      1. Niacinamide 50 mg orally every 8-12 hours until skin lesions resolve

X. Complications

XI. References

  1. Jhun et al. in Herbert (2016) EM:Rap 16(9): 8-10
  2. Rendon et al. (2017) Crit Dec Emerg Med 31(6): 15-21
  3. Ghosh (2013) Am Fam Physician 88(7):457-458 [PubMed]

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Ontology: Pellagra (C0030783)

Definition (MSH) A disease due to deficiency of NIACIN, a B-complex vitamin, or its precursor TRYPTOPHAN. It is characterized by scaly DERMATITIS which is often associated with DIARRHEA and DEMENTIA (the three D's).
Concepts Disease or Syndrome (T047)
MSH D010383
ICD9 265.2
ICD10 E52
SnomedCT 56550003, 238127001, 267491008, 154725000, 418186002, 418279001
English Pellagra, Pellagras, PELLAGRA, NIACIN DEFICIENCY <PELLAGRA>, Niacin deficiency [pellagra], pellagra, pellagra (diagnosis), NIACIN DEFICIENCY PELLAGRA, Pellagra [Disease/Finding], deficiencies niacin, deficiency niacin, nicotinamide deficiency, pellagra disorder, vitamin b3 deficiency, Niacin (-tryptophan) deficiency, niacin deficiency, deficiency; niacin, deficiency; nicotinamide, deficiency; nicotinic acid, niacin; deficiency, nicotinamide; deficiency, nicotinic acid deficiency, nicotinic acid; deficiency, Niacin-tryptophan deficiency, Niacin deficiency, Nicotinamide deficiency, Nicotinic acid deficiency, Vitamin PP deficiency, Vitamin B3 deficiency, Pellagra (disorder), Niacin deficiency (disorder)
Spanish deficiencia de niacina, deficiencia de nicotinamida, deficiencia de vitamina B3, deficiencia de ácido nicotínico, pelagra (trastorno), pelagra, deficiencia de niacina (trastorno), deficiencia de vitamina PP, hipovitaminosis PP, Déficit de ácido nicotínico, Pelagra
Italian Carenza di acido nicotinico, Pellagra
Dutch pellagra, deficiëntie; niacine, deficiëntie; nicotinamide, deficiëntie; nicotinezuur, niacine; deficiëntie, nicotinamide; deficiëntie, nicotinezuur; deficiëntie, Niacinedeficiëntie [pellagra], nicotinezuurdeficiëntie, Pellagra, Niacinedeficiëntie
French Pellagra, Carence en niacine, Carence en vitamine B3, Carence en vitamine PP, Carence en acide nicotinique, Pellagre
Japanese ペラグラ, ニコチン酸欠乏, ニコチンサンケツボウ, ペラグラ
Swedish Pellagra
Czech pelagra, Pelagra, Deficit kyseliny nikotinové
Finnish Pellagra
German Niazinmangel [Pellagra], Nikotinsaeuremangel, Pellagra
Korean 니아신 결핍증[펠라그라]
Polish Hipowitaminoza PP, Pelagra
Hungarian Pellagra, Nicotinsav hiány
Norwegian Pellagra
Portuguese Carência de ácido nicotínico, Pelagra