Pruritus Causes

1. See Also
   1. Pruritus
2. Causes: Dermatologic Conditions
   1. Dry Skin or Xerosis (most common cause)
   2. Atopic Dermatitis
   3. Allergic Contact Dermatitis
   4. Bullous Pemphigoid
   5. Dermatitis Herpetiformis
   6. Folliculitis
   7. Psoriasis
   8. Lichen Planus
   9. Mycosis Fungoides (Pruritus suggests worse prognosis)
   10. Sunburn
   11. Local Infection or bites
       1. Scabies
       2. Pediculosis corporis (lice)
       3. Bed Bugs
3. Causes: Systemic
   1. Iron Deficiency Anemia
   2. Severe Chronic Renal Failure (Uremic Pruritus)
   3. Neurodermatitis or Delusions of Parasitosis
   4. Polycythemia Rubra Vera (30-50%)
      1. Provoked by hot shower or bath
      2. Pricking type itch may persist for hours
   5. Hodgkin's Lymphoma
   6. Malignant Carcinoid
   7. Multiple Myeloma
   8. Scleroderma
   9. Malignant Carcinoid
   10. Rapid weight loss (e.g. Anorexia Nervosa)
   11. Hyperthyroidism (4-11% long-standing Grave's Disease)
   12. Urticaria
   13. Cholestasis (bile salt protease release in skin)
       1. See Cholestasis associated Pruritus
   14. Systemic infection
       1. HIV Infection (see Pruritus in HIV)
       2. Filariasis
       3. Schistosomiasis
       4. Onchocerciasis (river blindness)
       5. Ascariasis
       6. Hookworm
       7. Trichinosis
       8. Parvovirus B19
4. Causes: Localized
   1. Eye
      1. Allergic Blepharitis
      2. Allergic Conjunctivitis
      3. Atopic Dermatitis
      4. Contact Dermatitis
   2. Ear
      1. See Ear canal pruritus
   3. Scalp
      1. Pediculosis (Head Lice)
      2. Psoriasis
      3. Seborrheic Dermatitis
      4. Allergic Contact Dermatitis
      5. Pustule
   4. Back
      1. Notalgia Paresthetica
      2. Xerotic Eczema
      3. Psoriasis
      4. Folliculitis
      5. Cholestasis (Butterfly rash)
   5. Arm
      1. Brachioradial Pruritus
      2. Xerotic Eczema
      3. Eczematous Dermatitis (antecubital fossa)
   6. Hands
      1. Dyshidrotic Eczema
      2. Eczematous Dermatitis
      3. Contact Dermatitis
      4. Scabies (interdigital web space involvement)
   7. Groin or inguinal area
      1. See Pruritus Vulvae
      2. Candidiasis
      3. Tinea Cruris
      4. Erythrasma
      5. Contact Dermatitis
      6. Extramammary Paget's Disease
      7. Intertrigo
      8. Lichen Sclerosis et Atrophicus (LS&A)
      9. Pediculosis
      10. Scabies
   8. Rectum
      1. Pruritus Ani
      2. Anal Fissure
      3. Condylomata acuminata
      4. Pinworm
   9. Legs
      1. Xerotic Eczema (shin)
      2. Neurodermatitis
      3. Stasis Dermatitis
      4. Atopic Dermatitis (popliteal fossa)
      5. Lichen Simplex (lateral malleolus)
      6. Dermatitis Herpetiformis (knee)
      7. Cutaneous T-Cell Lymphoma (buttocks and thighs)
   10. Feet
       1. Tinea Pedis
       2. Eczematous Dermatitis
       3. Contact Dermatitis
       4. Scabies (interdigital web space involvement)
5. Causes: Exposure related Pruritus
   1. Water
      1. Aquagenic Pruritus
         1. Intense distressing itch after water contact
      2. Cholinergic Urticaria
      3. Polycythemia Vera (follows warm bath)
      4. Swimmer's Itch
   2. Pregnancy (See Pruritus in Pregnancy)
      1. Pruritic Urticarial Papules and Plaques of Pregnancy
      2. Prurigo of Pregnancy
      3. Herpes Gestationis or Pemphigoid Gestationis
      4. Cholestasis associated Pruritus (Prurigo gravidarum)
      5. Pruritic Folliculitis of Pregnancy
      6. Atopic Dermatitis
      7. Contact Dermatitis
   3. Medications
      1. Itraconazole, Fluconazole, Ketoconazole
      2. Niacinamide
      3. B Vitamins
      4. Aspirin
      5. Quinidine
      6. Ointments with high concentrations of inert oil
      7. Narcotics (especially via spinal administration)
      8. Hypersensitivity Reaction
         1. Rifampin
         2. Vancomycin
   4. Allergan or irritant exposure (e.g. Contact Dermatitis)
      1. Heat exposure: Miliaria rubra (Prickly heat)
      2. Cat exposure
      3. Fiberglass exposure (Fiberglass Dermatitis)
6. Age-related Pruritus Causes
   1. Children
      1. Atopic Dermatitis
      2. Contact Dermatitis
      3. Lice
      4. Scabies
      5. Parvovirus
      6. Pinworms
   2. Elderly
      1. Xerotic Eczema
      2. Contact Dermatitis
      3. Bullous Pemphigoid
      4. Herpes Zoster
      5. Mycosis Fungoides
7. References
   1. See Pruritus