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:
- 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 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)
- Some clues:
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:
- Pruritus due to inflammatory skin disease: treat the inflammatory skin disease
- 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