Urticaria and Angioedema — Viva Defence

Long case viva — chronic spontaneous urticaria

Candidate's opening statement (SASPOP)

"Doctor, my patient is a 34-year-old woman with a 2-year history of daily transient pruritic wheals and intermittent lip swelling, who works as a primary school teacher and who has coexisting Hashimoto thyroiditis on levothyroxine. Her symptoms impair her sleep and her teaching. Her problems are: chronic spontaneous urticaria with angioedema; Hashimoto thyroiditis; NSAID-exacerbated urticaria; and impaired quality of life." [1]

Problem list

1. Chronic spontaneous urticaria (CSU) with associated angioedema — mast-cell-driven, autoimmune subgroup likely.
2. Hashimoto thyroiditis (the associated autoimmune thyroid disease, present in 15 to 25 per cent).
3. NSAID-exacerbated urticaria (worsens with ibuprofen; pharmacologic COX-1 mechanism).
4. Impaired quality of life — sleep disturbance, reduced work productivity. [1]

Integrated management plan

Investigations — limited. Full blood count, CRP, thyroid function with anti-TPO antibodies. NO extensive allergy panel (CSU is not IgE-mediated food allergy; broad panels produce false positives). Confirm regular daily cetirizine dosing. [1]

Treatment ladder. Step 2: up-titrate cetirizine to up to 40 mg daily (up to 4-fold), the standard second step in the EAACI guideline and the step most often missed. If cetirizine sedates, switch to fexofenadine up to 720 mg daily. Step 3 if refractory: add omalizumab 300 mg SC every 4 weeks (ASTERIA II; 65 to 70 per cent response). Step 4 if refractory: add ciclosporin 2.5 to 4 mg per kg per day, specialist-supervised, with blood pressure and renal monitoring. [1]

Trigger avoidance. Avoid non-selective NSAIDs permanently (use paracetamol; celecoxib if an anti-inflammatory is needed). Treat thyroid dysfunction on its merits. [1]

Supportive. Acknowledge the quality-of-life impact; screen for anxiety and depression; counsel that CSU usually remits over months to years; avoid first-generation sedating antihistamines. [1]

Examiner probing questions

Examiner: "Why is her thyroid relevant?" Hashimoto thyroiditis and positive anti-TPO antibodies are associated with CSU in 15 to 25 per cent of patients, reflecting a shared autoimmune predisposition. The thyroid must be screened and dysfunction treated on its merits. Levothyroxine for euthyroid patients with positive antibodies is sometimes tried but evidence of benefit in CSU is limited. [1]

Examiner: "Why does the ibuprofen worsen her urticaria?" Non-selective NSAIDs inhibit cyclo-oxygenase-1, shunting arachidonic acid down the lipoxygenase pathway and increasing leukotriene production. Leukotrienes activate mast cells. About 20 to 30 per cent of CSU patients NSAID-exacerbate, and the effect class-shares across non-selective NSAIDs but not COX-2 selective inhibitors. This is pharmacologic, not IgE-mediated. [1]

Examiner: "Why is omalizumab effective in CSU if the disease is autoimmune?" Omalizumab binds free IgE, lowering the expression of FceRI on mast cells and basophils and reducing the cells' responsiveness to the activating autoantibodies. It also may have direct effects on mast cell signalling. The ASTERIA I, II, and GLACIAL trials showed 300 mg every 4 weeks significantly reduced itch and wheal activity. [1]

Examiner: "When would you suspect urticarial vasculitis instead of CSU?" If an individual wheal lasts more than 24 hours, leaves bruising or pigmentation, is painful rather than pruritic, or is accompanied by arthralgia, fever, or renal involvement. Then I biopsy a fresh lesion (4 mm punch, histology and immunofluorescence) and check complement and autoimmune screen. [1]