investigations

Last reviewed 01/2018

First line investigation in patient with pruritus with no obvious cause:

  • detailed history and examination -
    • timing of itch - day or night,  intermittent or continuous
    • nature – burning (in Hodgkin disease), pricking (occurs most frequently after hot baths in polycythaemia rubra vera patients) (1,2), crawling (3)
    • location - scapula/subscapula, palms of hand and soles of feet (in cholestasis)
    • provoking factors - activity/exercise, cold, water, sunlight
    • medications – opioids
    • physical examination – dry skin, scabies, mental status (1)
  • laboratory investigations
    • urine - dipstick for glucose
    • blood tests - FBC, ESR, U+Es, Ca, LFTs, Fe, TFTs, immunoglobulins (1)
  • other investigations
    • consider chest X-ray
    • abdominal ultrasound (lymphoma)
    • skin biopsy (1)

Patients who complain of itch who have a definite skin lesion do not usually need further investigation (3). Exceptions include the use of patch testing in suspected allergies and a skin biopsy in the case of suspected dermatitis herpetiformis.

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