Pruritus

Pruritus can be a common complaint endorsed in both ambulatory and inpatient settings.

The best strategy for approaching pruritus is to stratify the pruritus into:

  1. Pruritus related to an underlying skin condition
    • Skin is abnormal with evidence of inflammation
    • common primary skin disorders that may be associated with pruritus are indicated in the table below

      Pruritus due to skin disease.png

  2. Pruritus related to a systemic process
    • Skin is normal OR
    • The only skin abnormalities are related to chronic rubbing or scratching
      • Some clues:
        • Lichenification (thickened skin) or prurigo nodules (thickened, dark nodules)
        • Erosions in a linear pattern
        • Butterfly sign (sparing of the mid-back in a region that cannot be access for direct scratching)
    • Pruritus Systemic.png

When a secondary/systemic etiology is being considered, a comprehensive history and physical should be directed to evaluate for renal, liver, hematologic, endocrine, infectious, or autoimmune disease (as indicated in above table).

A basic series of investigations might include:

  • CBC + Blood Film
  • LDH, Uric acid, CXR +/- Flow cytometry of peripheral blood
  • Creatinine and urea with electrolyte and extended electrolyte panel
  • Liver enzymes, GGT, INR, Bilirubin, and bile acids along with hCG (age/gender-appropriate)
  • TSH

Depending on the clinical history and examination, additional testing could include evaluation for connective tissue disorders as well as HIV and DM.

Principles of Pruritus Management:

  1. Pruritus due to inflammatory skin disease: treat the inflammatory skin disease
  2. Other general pruritus strategies include:
    • Nonpharmacologic: loose-fitting garments, moisturizer usage, reduced bathing, CBT/Biofeedback
    • Pharmacologic:
      • Topical: lidocaine, menthol, capsaicin
      • Systemic: Antihistamines, neuropathic agents (gabapentin, pregabalin)
      • Other: Phototherapy

Further Study:

  • The American Academy of Dermatology offers a free, web-based Basic Dermatology curriculum consisting of multiple modules on high-yield, commonly encountered dermatology topics. Many of these are relevant for trainees of all backgrounds. Follow the link for more information: AAD Basic Dermatology Curriculum

 

 

 

 

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