(BMJ)—A woman in her 50s presented with a 2-day hx of rash and tingling sensation on her thighs, but no pruritus. Exam: annular and targetoid eruptions with symmetric rings of ecchymosis. No systemic findings. CBC with diff, erythrocyte sedimentation rate, C3, C4, cryoglobulin, autoimmune panel all WNL. Skin bx revealed the dx. What is it?
Schnitzler syndrome
Lyme disease
Acute allergic reaction
Erythema multiforme
Urticarial vasculitis
You are correct. Skin bx showed features compatible with urticarial vasculitis. No deposition of immune complexes was seen under direct immunofluorescence.

Urticarial vasculitis is a small-vessel vasculitis with predominantly cutaneous involvement. In most cases, the cause is idiopathic, but the condition can be precipitated by drugs, infections, autoimmune disease, and, rarely, malignancy.

Consider urticarial vasculitis in patients presenting with this characteristic skin eruption who experience pain/tingling rather than pruritus.

BMJ 2021;373:n1457