URTICARIA PIGMENTOSA iii

Diagnosis: URTICARIA PIGMENTOSA iii

Case submitted by Dr.Azeem Alam Khan to the dermRounds community.

Clinical Presentation

Clinical photograph(s) submitted for peer review and discussion.

Clinical History

Submitted by Dr.Azeem Alam Khan. Originally posted September 29, 2009.

Treatment

See case discussion.

Differential Diagnosis

• Urticarial vasculitis • Drug eruption • Contact dermatitis • Erythema multiforme • Bullous pemphigoid (urticarial phase) • Insect bites (papular urticaria) • Dermatographism • Mastocytosis

Key Learnings

• Individual wheals resolve within 24 hours without residual marks — if lasting >24 hours, consider urticarial vasculitis • Acute urticaria (6 weeks): usually idiopathic; autoimmune mechanism in ~40% • CSU workup: CBC, ESR/CRP, TSH; extensive testing is low-yield • Omalizumab (anti-IgE) is FDA-approved for CSU refractory to antihistamines • Angioedema: deeper involvement — ACE inhibitor-induced angioedema is bradykinin-mediated (antihistamines won't work) • Second-generation antihistamines at up to 4× standard dose before escalating therapy

Tags: urticaria, pigmentosa, iii, dr.azeem alam khan