What is the diagnosis and treatment for a patient with a circular pale skin lesion on the face associated with pruritus?

Diagnosis and Management of Circular Pale Facial Lesion with Pruritus

The most likely diagnosis is tinea faciei (facial dermatophyte infection), which should be treated with topical antifungal therapy as first-line management, specifically topical azole antifungals applied twice daily for 2-4 weeks. 1

Clinical Diagnosis

The presentation of a circular pale skin lesion on the face with associated pruritus is highly characteristic of:

• Tinea faciei: A superficial fungal infection presenting as annular (circular) lesions with central clearing (appearing pale), raised borders, and associated pruritus 1
• The face is a common location for dermatophyte infections, though less frequently affected than the trunk or extremities 2

Diagnostic Confirmation

Before initiating treatment, obtain:

• Skin scraping with KOH preparation: Scrape the active border of the lesion to identify fungal hyphae 3
• Fungal culture: If KOH is negative but clinical suspicion remains high 3
• Consider skin biopsy only if the diagnosis remains uncertain after initial testing or if the lesion fails to respond to antifungal therapy 3

First-Line Treatment Algorithm

Topical Antifungal Therapy

Apply topical azole antifungals (clotrimazole 1% cream or miconazole 2% cream) twice daily to the affected area and 2-3 cm beyond the visible border for 2-4 weeks. 4, 1

• Topical azoles achieve 80-90% cure rates for superficial dermatophyte infections 4
• Continue treatment for at least 1 week after clinical resolution to prevent recurrence 4

Symptomatic Pruritus Management

While awaiting antifungal efficacy:

• Apply emollients regularly to maintain skin barrier function and reduce irritation 4, 5
• Keep fingernails short to minimize excoriation from scratching 4
• Add non-sedating antihistamines if pruritus is severe: fexofenadine 180 mg daily or loratadine 10 mg daily 4, 5
• Avoid sedating antihistamines (hydroxyzine, diphenhydramine) due to risk of cognitive impairment and falls 5

Adjunctive Topical Therapy for Inflammation

If significant inflammation or dermatitis is present alongside the fungal infection:

• Apply low-potency topical corticosteroid (hydrocortisone 2.5%) to affected area 3-4 times daily for symptomatic relief 6, 1
• Critical pitfall: Do not use topical steroids alone without concurrent antifungal therapy, as this can worsen fungal infections by suppressing local immune response 5
• Use corticosteroids only for the first 3-5 days while antifungals take effect 7

Alternative Diagnoses to Consider

If the lesion does not respond to antifungal therapy within 2-4 weeks, reassess for:

Nummular Eczema

• Presents as coin-shaped patches but typically more erythematous than pale 7, 1
• Treat with moderate-potency topical corticosteroids (triamcinolone 0.1%) twice daily for at least 2 weeks 5, 1

Pityriasis Alba

• Common in children and young adults, presents as hypopigmented patches on face 8
• Generally self-limited; treat with emollients and low-potency topical steroids if symptomatic 7

Early Cutaneous Lymphoma

• Rare but important not to miss, especially if lesions persist despite appropriate treatment 5
• Requires skin biopsy for diagnosis 2

When to Escalate or Refer

Refer to dermatology if: 4, 5

• No improvement after 4 weeks of appropriate topical antifungal therapy
• Diagnostic uncertainty persists after initial evaluation and testing
• Lesions are extensive or rapidly progressive
• Patient is immunocompromised (consider systemic antifungal therapy)

Systemic Therapy for Refractory Cases

If topical therapy fails and tinea faciei is confirmed:

• Oral terbinafine 250 mg daily for 2-4 weeks or oral itraconazole 200 mg daily for 2-4 weeks 1
• Systemic therapy is particularly indicated for extensive lesions or immunocompromised patients 1

Common Pitfalls to Avoid

• Do not apply topical antibiotics (neomycin, bacitracin) as these are common allergens that can worsen dermatitis and do not treat fungal infections 5
• Do not assume all circular facial lesions are fungal; 20-30% of pruritic skin conditions have alternative diagnoses requiring different management 4
• Do not use high-potency topical steroids on the face due to risk of skin atrophy, telangiectasia, and perioral dermatitis 5, 7
• Do not discontinue antifungal therapy prematurely when symptoms improve; complete the full course to prevent recurrence 4