Chronic Inducible Urticaria (CIndU)/Physical Urticaria
Diagnosis
• Diagnosis is based on clinical history and can be confirmed via provocation testing, if available
• Challenge/provocation testing considerations: risk of anaphylaxis (especially if history of severe reactions), need to discontinue urticaria treatments (stop anti-histamines for at least 5 half-lives, glucocorticoids for at least 7 days) [9]
o Indications:
▪ Determine relevant triggers
▪ Evaluate trigger thresholds
▪ Monitor treatment
▪ Testing site: ideally at areas that have not been impacted by hives in the preceding 24H (refractory period), sometimes need to be done at sites impacted by hives previously as other sites may be falsely negative [9]
o Urticaria develops after stimulus is removed (do not wait until urticaria develop to remove stimulus)