Synopsis
Recognise chronic spontaneous and inducible urticaria, separate mast-cell angioedema from bradykinin disease and vasculitis, investigate selectively and escalate non-sedating antihistamine treatment without unnecessary food restriction.
- Urticaria produces itchy raised wheals that migrate and usually disappear from each site within 24 hours; chronic means recurring on most days for more than six weeks.
- Angioedema affects deeper eyelid, lip, hand, foot or genital tissue and may last up to 72 hours; airway symptoms require an anaphylaxis pathway.
- Chronic spontaneous urticaria in children is rarely driven by food allergy, so broad IgE panels and exclusion diets are usually harmful.
- Ask for photographs and lesion duration, triggers, NSAIDs, infection, physical stimuli and systemic symptoms; provocation testing confirms suspected inducible forms.
- Do not routinely order large autoimmune, infectious or allergy screens in an otherwise well child with classic transient wheals.
- Use a daily second-generation non-sedating H1 antihistamine rather than as-needed first-generation sedatives; check adherence before declaring failure.
- Under specialist guidance, increase a second-generation antihistamine up to fourfold the licensed standard dose when ordinary dosing fails, with age-appropriate selection and monitoring.
- Omalizumab is a specialist add-on for severe chronic spontaneous urticaria from age 12 when high-dose H1 treatment remains inadequate; ciclosporin is a later selected option.
- Systemic corticosteroids are not maintenance therapy; a very short rescue course is reserved for exceptional severe flares under a clear plan.
- Recurrent isolated angioedema without wheals needs C4 and C1-inhibitor assessment and a separate hereditary-angioedema emergency plan.
Key red flags
Angioedema with tongue or laryngeal symptoms, breathing difficulty or circulatory change is an emergency regardless of whether urticaria is visible.
Individual lesions that remain fixed beyond 24 hours, hurt or burn and leave bruising or pigmentation suggest urticarial vasculitis and need specialist investigation.
Recurrent non-itchy angioedema without wheals, especially with abdominal pain or family history, suggests hereditary C1-inhibitor deficiency.
Fever, bone pain, weight loss, lymphadenopathy, hepatosplenomegaly or persistently abnormal inflammatory markers broadens systemic inflammatory, infectious and malignant differentials.
Food is rarely the cause of near-daily wheals for more than six weeks; temporal claims need reproducible immediate exposure evidence before restriction.
Sedation, school impairment or paradoxical excitation from first-generation antihistamines is avoidable and should prompt a second-generation regimen.
Investigation priorities
Confirm evanescence, distinguish wheals from fixed inflammation and document angioedema distribution.
Management branches
Wheals or swelling appear acutely or recur.
- Assess airway, breathing and circulation and give adrenaline if anaphylaxis physiology is present.
- Confirm lesion duration, itch, bruising and whether angioedema occurs with or without wheals.
- Escalate fixed vasculitic lesions and isolated laryngeal or abdominal swelling through the correct pathway.