Dyshidrotic eczema
- Etiology & Risk Factors
- Young adults (<40 yo) with atopic diathesis (atopic dermatitis, asthma, allergic rhinitis).
- Triggers: Hyperhidrosis, frequent wet work/handwashing, nickel/contact allergens, emotional stress.
- Clinical Presentation
- Intense pruritus or burning preceding lesions.
- “Tapioca pudding” vesicles: Deep-seated, tense, clear vesicular clusters.
- Distribution: Lateral fingers/toes, palms, and soles (classically symmetric).
- Late stage: Scaling, desquamation, lichenification, and painful fissures.
- Diagnosis
- Clinical diagnosis based on history and characteristic lesions.
- KOH prep: Essential initial step to rule out dermatophyte infection (Tinea).
- Patch testing: Indicated for recurrent/chronic cases to identify contact allergens.
- High-Yield Differentials
- Tinea manuum/pedis: (+) KOH (branching hyphae), asymmetric (“two feet, one hand”).
- Scabies: Nocturnal pruritus, burrows in web spaces, (+) mineral oil scraping for mites/eggs.
- Herpetic whitlow: Severe localized pain (not itch), single digit, (+) HSV PCR.
- Palmoplantar pustulosis: Primary sterile yellow pustules, not clear vesicles.
- Management
- General: Emollients (petrolatum), avoid harsh soaps/wet work, wear cotton gloves.
- 1st-line: Super-high-potency topical corticosteroids (e.g., Clobetasol 0.05% ointment).
- Severe/Disabling: Short taper of oral corticosteroids (e.g., Prednisone).
- Refractory/Maintenance: Topical calcineurin inhibitors (Tacrolimus), phototherapy (PUVA/narrowband UV-B), or Dupilumab.
- Complications
- Secondary bacterial superinfection (most commonly Staphylococcus aureus impetiginization/cellulitis).