What are the treatment approaches for contact dermatitis, dyshidrotic eczema, and herpetic whitlow?

Treatment Approaches for Contact Dermatitis, Dyshidrotic Eczema, and Herpetic Whitlow

Each of these conditions requires distinct treatment approaches, with contact dermatitis and dyshidrotic eczema primarily managed with topical corticosteroids and barrier repair, while herpetic whitlow requires antiviral therapy.

Contact Dermatitis

Diagnosis

• Determine whether allergic or irritant contact dermatitis through:
  • Detailed history of exposure to potential allergens or irritants
  • Pattern and distribution of lesions
  • Patch testing for persistent or recurrent cases 1

Treatment Algorithm

1. First-line treatment:

   • Identify and avoid triggering substances 1
   • Apply medium-potency topical corticosteroids (for body) or low-potency corticosteroids (for face) once daily for 2-4 weeks 2
   • Use moisturizers liberally after bathing to repair skin barrier 1

2. For severe or widespread cases:

   • High-potency topical corticosteroids for short periods (≤2 weeks) on thickened areas 2, 3
   • Consider systemic steroids if >20% body surface area is affected 4
   • Oral antihistamines for severe itching 2

3. For chronic/recalcitrant cases:

   • Consider topical tacrolimus where steroids are unsuitable 1
   • Consider referral for phototherapy (PUVA) 1
   • Consider alitretinoin for chronic hand dermatitis 1

Important Cautions

• Avoid potent topical corticosteroids on face, groin, or axillae 3
• Limit superpotent corticosteroids to ≤2 weeks to prevent HPA axis suppression 3
• Pediatric patients may be more susceptible to systemic toxicity from topical steroids 3

Dyshidrotic Eczema (Pompholyx)

Diagnosis

• Characterized by pruritic vesicles on palms, soles, and lateral aspects of fingers
• May be triggered by contact allergens, metals (especially nickel), or stress

Treatment Algorithm

1. Acute phase:

   • Compresses with saline or aluminum acetate solution for vesicular lesions
   • Medium to high-potency topical corticosteroids applied once daily 2
   • Oral antihistamines for itching 2

2. Chronic phase:

   • Regular use of emollients and moisturizers 1
   • "Soak and smear" technique: soak hands in plain water for 20 minutes and immediately apply moisturizer to damp skin nightly for up to 2 weeks 1
   • Consider occlusion with cotton gloves at night after moisturizer application 1

3. For severe or recalcitrant cases:

   • Consider PUVA therapy 1
   • Consider alitretinoin for chronic hand eczema 1
   • For severe cases, systemic immunosuppressants may be needed 2

Herpetic Whitlow

Diagnosis

• Characterized by painful erythema and vesicles/bullae on finger
• Caused by HSV-1 or HSV-2 infection 5, 6
• PCR testing of vesicle fluid can confirm diagnosis 5

Treatment Algorithm

1. First-line treatment:

   • Oral acyclovir 200 mg five times daily for 5 days for mild to moderate cases 7
   • For severe cases or immunocompromised patients, consider intravenous acyclovir 2
   • Avoid topical steroids which may worsen infection

2. Important precautions:

   • Avoid surgical intervention which may spread infection 6
   • Use gloves when handling secretions to prevent transmission 6
   • Healthcare workers with active lesions should avoid patient care 6

3. For recurrent cases:

   • Consider suppressive antiviral therapy
   • Evaluate for underlying immunosuppression

Key Differences and Pitfalls

Differential Diagnosis Pitfalls

• Contact dermatitis and dyshidrotic eczema can appear similar on hands
• Herpetic whitlow can be misdiagnosed as bacterial infection, leading to inappropriate surgical drainage 6
• Systemic contact dermatitis can present with widespread eruption after systemic exposure to allergens 8

Treatment Pitfalls to Avoid

• Using topical antibiotics long-term (risk of resistance and sensitization) 2
• Using topical antihistamines (risk of contact sensitization) 2
• Treating herpetic whitlow with corticosteroids or incision and drainage
• Undertreatment of contact dermatitis with insufficient potency corticosteroids 2
• Prolonged use of high-potency corticosteroids, especially on the face 3

By following these evidence-based treatment approaches and recognizing the distinct characteristics of each condition, clinicians can effectively manage these common dermatological conditions while minimizing complications and improving quality of life.