What is the recommended treatment for absolute eosinophil (eosinophil count elevation) elevation associated with eczema (atopic dermatitis)?

Treatment of Eosinophilia Associated with Atopic Dermatitis

The elevated eosinophil count in eczema is a marker of disease activity and does not require separate treatment—focus on controlling the underlying eczema with topical anti-inflammatory therapy, which will secondarily normalize the eosinophil count.

Understanding the Relationship

Eosinophilia in atopic dermatitis reflects the Th2-mediated inflammatory process driving the skin disease. The eosinophil elevation resolves when eczema is adequately controlled, making it an indicator rather than a separate treatment target.

First-Line Treatment Approach

Initiate aggressive topical corticosteroid therapy as the mainstay of treatment:

• Apply potent topical corticosteroids (such as mometasone furoate 0.1% ointment) once daily to all affected areas 1, 2
• Potent TCS rank among the most effective treatments, with odds ratios of 5.99-8.15 for symptom control compared to vehicle 2
• Once-daily application is as effective as twice-daily and improves adherence 3

Combine with liberal emollient use:

• Apply fragrance-free emollients to the entire body at least once daily, not just affected areas, to restore skin barrier function 1
• Use soap-free cleansers to avoid further barrier disruption 1

Potency Selection Based on Severity

For moderate to severe eczema:

• Use potent to very potent TCS (class II-IV) for initial control 4, 2
• Very potent TCS showed standardized mean differences of -1.87 to -1.99 for symptom improvement 2

For mild eczema or maintenance:

• Step down to mild to moderate potency TCS once control is achieved 4, 1

Alternative First-Line Options for Sensitive Areas

For facial, eyelid, or intertriginous involvement where steroid atrophy is a concern:

• Use tacrolimus 0.1% ointment twice daily (adults) or tacrolimus 0.03% twice daily (children) 2, 5
• Tacrolimus 0.1% ranks similarly to potent TCS in effectiveness (OR 5.06-8.06) without risk of skin atrophy 2
• In children with moderate-severe disease, tacrolimus 0.03% twice daily achieved 76.7% median improvement in disease severity versus 47.6% with 1% hydrocortisone 5

Important caveat: Tacrolimus causes transient burning/stinging in the first 3-4 days of use, occurring more frequently than with TCS, but this typically resolves 5, 2

Maintenance Strategy: "Get Control Then Keep Control"

Once eczema is controlled (clear or almost clear):

• Apply mometasone or other moderate-potency TCS twice weekly to previously affected areas for up to 36 weeks to prevent relapses 1
• This proactive maintenance approach achieves 68% remission rates over 36 weeks 1

Management of Secondary Infection

If crusting, weeping, or clinical signs of infection are present:

• Add flucloxacillin as the first-line antibiotic for Staphylococcus aureus (the most common pathogen) before or concurrent with corticosteroid therapy 4, 1
• Use phenoxymethylpenicillin if β-hemolytic streptococci are isolated 4
• Erythromycin is an alternative for penicillin allergy or flucloxacillin resistance 4

Critical point: Do not use topical or oral antibiotics for non-infected eczema, as evidence does not support their routine use 3

What NOT to Do

Avoid these interventions that lack evidence:

• Oral antihistamines for itch control have minimal benefit beyond sedation and should only be used short-term at night for severe pruritus 4, 3
• Non-sedating antihistamines have "little or no value in atopic eczema" 4
• Probiotics have no proven benefit for treating established eczema 3

When to Escalate Treatment

Consider systemic corticosteroids only as a last resort:

• Reserve oral prednisone for severe, refractory cases after all topical options have been exhausted 4, 6
• Systemic steroids "should never be taken lightly" and are not appropriate for maintenance therapy 4
• Use only to "tide the patient over" acute severe exacerbations 4

Monitoring the Eosinophil Count

The eosinophil elevation will normalize as the eczema improves with appropriate topical anti-inflammatory treatment. No specific therapy targeting eosinophils is needed—the eosinophilia is simply a biomarker of disease activity that resolves with effective eczema control.

Safety Considerations for Topical Corticosteroids

Short-term use (median 3 weeks) shows no evidence of skin atrophy:

• No increased risk of skin thinning with mild, moderate, potent, or very potent TCS used for 1-16 weeks 2

Long-term use (6-60 months) carries atrophy risk:

• Increased skin thinning observed with prolonged mild to potent TCS use compared to topical calcineurin inhibitors 2
• This supports the "get control then keep control" approach with intermittent rather than continuous application 1