What is the treatment for eosinophilic folliculitis?

Treatment of Eosinophilic Folliculitis

Topical corticosteroids are the first-line treatment for eosinophilic pustular folliculitis, followed by oral indomethacin if topical therapy fails. 1

Types of Eosinophilic Folliculitis

Eosinophilic pustular folliculitis (EPF) has several variants:

• Classic type (Ofuji disease) - most common in Japan
• HIV-associated type
• Infantile type
• Palmoplantar type
• Medication-associated variant
• Neoplasia-associated variant

Diagnostic Approach

A skin biopsy is essential to confirm the diagnosis of EPF, which typically shows:

• Subcorneal eosinophilic and neutrophilic pustules in the follicular infundibulum
• Marked spongiosis of the follicular epithelium
• Perivascular mixed inflammatory cell infiltrate with eosinophils, neutrophils, and lymphocytes 2

Laboratory findings may include:

• Peripheral eosinophilia
• Elevated serum IgE levels
• Negative bacterial and fungal cultures from pustules 2

Treatment Algorithm

First-line Treatment:

• Topical corticosteroids - potent formulations applied twice daily to affected areas 1

Second-line Options (if topical corticosteroids fail):

• Oral indomethacin (50-75 mg/day) - highly effective for classic EPF but can cause peptic ulcers 1, 3
• Topical tacrolimus 0.1% ointment - effective steroid-sparing agent, especially for recurrent cases 4

Additional Treatment Options for Refractory Cases:

• HIV-associated EPF specific options:

  • Cetirizine (20-40 mg/day)
  • Metronidazole (250 mg three times daily)
  • Itraconazole (starting at 200 mg/day, increasing to 300-400 mg/day)
  • Topical permethrin
  • UVB phototherapy (considered the "gold standard" for HIV-associated EPF) 1, 5

• Other options for resistant cases:

  • PUVA photochemotherapy
  • Oral corticosteroids (prednisolone 30 mg in divided doses) 2
  • Synthetic retinoids (isotretinoin 1 mg/kg/day or acitretin 0.5 mg/kg/day)
  • Cyclosporine (5 mg/kg/day)
  • Minocycline (100 mg twice daily)
  • Dapsone (50-100 mg twice daily) 1

Special Considerations

1. HIV-associated EPF:

   • Test for HIV in suspected cases
   • Highly active antiretroviral therapy (HAART) may lead to resolution as CD4 counts rise above 250/mm³ 1, 5
   • Multiple biopsies may be needed to confirm diagnosis 5

2. Long-term management:

   • EPF is often chronic and recurrent
   • Avoid prolonged use of topical steroids due to risk of skin atrophy, hypertrichosis, and dyspigmentation 4
   • Consider maintenance therapy with steroid-sparing agents like tacrolimus for recurrent cases

3. Pathergy phenomenon:

   • Some patients develop new lesions at sites of trauma or scratching
   • Advise patients to avoid scratching to prevent spread of lesions 2

Monitoring and Follow-up

• Regular follow-up to assess treatment response
• Monitor for side effects of medications (especially gastrointestinal effects with indomethacin)
• Consider alternative therapies if initial treatment fails after 2-4 weeks
• Be prepared for relapses, which are common with this condition

Treatment Pitfalls to Avoid

1. Failing to confirm diagnosis with skin biopsy before initiating treatment
2. Prolonged use of high-potency topical steroids without considering steroid-sparing alternatives
3. Not considering HIV testing in appropriate clinical scenarios
4. Overlooking the potential for drug-induced variants of EPF

The diversity of clinical presentations suggests that EPF may be a reaction pattern rather than a single disease entity, so therapy should be tailored to the specific variant and underlying etiology 1.