Pruritus

An unpleasant cutaneous sensation that elicits the desire to scratch, mediated by specialized pruriceptive neural pathways distinct from nociceptive pain pathways.

Causes

• Dermatologic causes

  • Dry skin (xerosis)

  • Eczema

  • Psoriasis

  • Contact dermatitis

  • Scabies

  • Lice infestation

  • Insect bites

  • Fungal infections

  • Bacterial skin infections

• Systemic causes

  • Liver failure and cholestatic liver disease

  • Kidney failure

  • Hyperthyroidism

  • Hypothyroidism

  • Anemia

  • Polycythemia vera

• Neurological causes

  • Herpes zoster

  • Pinched nerves

  • Multiple sclerosis

  • Peripheral neuropathy

• Psychogenic causes

  • Stress

  • Anxiety

  • Depression

  • Obsessive-compulsive disorder

• Medication-induced hypersensitivity reactions

  • Opioids

  • Antihypertensive medications

• Environmental causes

  • Chemical irritants

  • Wool or other irritating fabrics

  • Extreme dryness or environmental allergens

• Other causes

  • Pregnancy-associated pruritus

  • Malignancy-associated pruritus

  • Idiopathic pruritus