What is the diagnosis and treatment for a patient with random circular itchy lesions (pruritic lesions) that appear all over their body with a lighter central clearing, and how should they be managed?

Urticaria (Hives)

This presentation is most consistent with urticaria (hives), and the primary treatment is non-sedating antihistamines with avoidance of identified triggers.

Clinical Diagnosis

The description of random circular itchy lesions with lighter central clearing that appear and disappear spontaneously across the body is pathognomonic for urticaria. While the provided evidence focuses on other dermatologic conditions, this classic presentation—transient wheals with central pallor and peripheral erythema—is diagnostic of urticaria rather than the fungal infections (tinea corporis) or other conditions discussed in the evidence.

Key Distinguishing Features

Urticaria differs from tinea corporis in several critical ways:

• Lesion behavior: Urticaria lesions are transient, typically lasting less than 24 hours at any single site before resolving and appearing elsewhere, whereas tinea corporis lesions are fixed and slowly expand 1, 2
• Scale presence: Tinea corporis presents with scaly borders and scaling within the lesion 1, 2, while urticaria has smooth, edematous wheals without scale
• Central clearing mechanism: In tinea, central clearing occurs due to fungal growth pattern at the periphery 2; in urticaria, central pallor results from dermal edema compressing superficial vessels

First-Line Treatment Approach

Begin with second-generation (non-sedating) antihistamines:

• Start with cetirizine 10 mg daily, loratadine 10 mg daily, or fexofenadina 180 mg daily 3
• These can be safely increased up to 4 times the standard dose if symptoms persist after 2 weeks
• Avoid first-generation sedating antihistamines in routine management due to cognitive impairment and anticholinergic effects 4

Supportive Measures

Implement trigger avoidance and skin care:

• Avoid hot water; use tepid water for bathing 3
• Avoid harsh soaps and use mild, pH-neutral non-soap cleansers 3
• Keep nails short to minimize trauma from scratching 3
• Avoid alcohol-containing preparations that worsen skin irritation 3
• Apply fragrance-free moisturizers after bathing to damp skin 3

When Initial Treatment Fails

If symptoms persist despite optimized antihistamine therapy after 4 weeks:

• Consider short course of oral corticosteroids for acute severe flares (though not for chronic management) 4
• Evaluate for underlying causes including thyroid disease, infections, or malignancy with appropriate laboratory testing 4
• Refer to dermatology for consideration of second-line agents such as omalizumab or immunosuppressants 3

Critical Pitfalls to Avoid

Do not misdiagnose as tinea corporis and treat with antifungals alone, as this delays appropriate antihistamine therapy. If there is genuine diagnostic uncertainty between urticaria and tinea corporis, perform KOH preparation or fungal culture before initiating antifungal treatment 1, 2.

Avoid topical corticosteroids as monotherapy for widespread lesions, as they provide minimal benefit for urticaria and can cause skin atrophy with prolonged use 3. The exception would be if this were actually tinea corporis misdiagnosed as urticaria—in which case topical steroids would worsen the infection by causing local immunosuppression 5, 6.

Do not overlook secondary bacterial infection if lesions become crusted, weeping, or show signs of superinfection, which would require appropriate antibiotic therapy 3.