Dermatology Book

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Pruritic ConditionAka: Pruritus, Itch

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  1. See Also
    1. Pruritus Causes
    2. Pruritus Management
  2. Definition: Pruritus
    1. Unpleasant cutaneous sensation provoking scratching
    2. Itch
  3. Epidemiology
    1. Very common in elderly patients
  4. Pathophysiology
    1. Nerve fiber involvement
      1. Origin of itch is within skin free nerve endings
        1. Fibers most concentrated in wrists and ankles
        2. Unmyelinated C fibers to dorsal horn in spinal cord
      2. Scratching is a spinal reflex response
      3. Ascends to cerebral cortex via spinothalamic tract
    2. Chemical mediators
      1. Substance P
      2. Opioid and nonopioid peptides
      3. Somatostatin
      4. Neurokinin A
      5. Histamine
      6. Serotonin
      7. Prostaglandins
    3. External mediators
      1. Skin inflammation
      2. Environmental heat or dryness
      3. Vasodilation
      4. Psychological concerns
  5. Causes
    1. See Pruritus Causes
  6. Evaluation
    1. Identify primary Dermatologic Causes of Pruritus
      1. Atopic Dermatitis: Atopy, Asthma, or Urticaria
      2. Contagious contacts (Pediculosis or Scabies)
      3. Consider Localized Causes of Pruritus
      4. Consider Timing (Xerotic Eczema worse in winter)
    2. Identify potential exposures
      1. See Environmental Causes of Pruritus
      2. See Medication Causes of Pruritus
    3. Review mental health concerns (e.g. Major Depression)
    4. Consider Systemic Causes of Pruritus
      1. Observe for cholestasis (e.g. Jaundice, Hepatomegaly)
      2. Observe for Lymphadenopathy
      3. Observe for thyromegaly
  7. Labs: Systemic Cause Evaluation
    1. Approach
      1. Base lab testing on history and physical
      2. Avoid broad shotgun approach to lab testing
    2. Dermatologic Cause Evaluation
      1. Skin Scrapings for Scabies and dermatophytosis
      2. Skin biopsy
        1. Mastocytosis
        2. Mycosis Fungoides
        3. Autoimmune Bullous Disease
    3. Systemic Cause Evaluation
      1. Thyroid Function Test (evaluate for Hyperthyroidism)
      2. HIV Test for high risk behaviors
      3. Liver Function Tests (evaluate for cholestasis)
        1. Serum Bilirubin
        2. Alkaline Phosphatase
      4. Hematologic tests
        1. Serum Ferritin
        2. Blood Urea Nitrogen (BUN)
        3. Complete Blood Count (CBC)
        4. Calcium
        5. Albumin
  8. Radiology: Systemic Cause Evaluation
    1. Chest XRay (if Lymphoma suspected)
    2. Right upper quadrant ultrasound (for cholestasis)
  9. Complications of persistent scratching
    1. Bacterial superinfection
    2. Lichen Simplex Chronicus
      1. Thickened skin in response to repeated scratching
  10. Management
    1. See Nonspecific Management of Pruritus
  11. References
    1. Shellow in Goroll (2000) Primary Care, p. 1001-4
    2. Bernhard (1990) Adv Dermatol 6:57
    3. Fleisher (1995) Adv Dermatol 10:41
    4. Garden (1985) Arch Dermatol 121(11):1415
    5. Gilchrest (1982) Arch Dermatol 118(3):154
    6. Greco (1992) J Gen Intern Med 7:340
    7. Gupta (1992) J Am Acad Dermatol 27(1):118
    8. Hagermark (1995) Semin Dermatol 14:320
    9. Kam (1996) Anaesthesia 51:1133
    10. Kantor (1995) Semin Dermatol 14:290
    11. Millikan (1996) Postgrad Med 99:173
    12. Swerlick (1985) J Am Acad Dermatol 13(4):675
    13. Teofoli (1996) Int J Dermatol 35:159
    14. Valsecchi (1983) Arch Dermatol 119(8):630

Pruritus (C0033774)

Definition (MSH)An intense itching sensation that produces the urge to rub or scratch the skin to obtain relief.
Definition (CSP)intense itching sensation that produces the urge to rub or scratch the skin to obtain relief.
Definition (NCI)An intense itching sensation.
ConceptsDisease or Syndrome (T047)
ICD9698.9
EnglishIrritating sensation, Itch, Itch of skin, Itching, Itching of skin, itching skin, Itchy, Pruritic dermatitis, Pruritic disorder, Pruritic disorders, PRURITIS, Pruritus, Pruritus of skin, Skin Pruritus, Unspecified pruritic disorder
Hebrewiktzutz
NorwegianHUDKLOE/IRRITASJON EKS X16
Spanishdermatitis pruriginosa, dermatitis pruriginosas, enfermedad pruriginosa, enfermedades pruriginosas, escozor, picar, picazón, picazón de la piel, picazon, picazon de la piel, prurito, prurito cutáneo, prurito cutaneo, prurito de la piel, trastorno pruriginoso, trastornos pruriginosos de la piel
CreditsDerived from the NIH UMLS (Unified Medical Language System)



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