View source for Cold urticaria

==Background==
*Subtype of physical [[urticaria]] (i.e. urticaria in response to a physical stimulus)
*In rare cases, can lead to fatal [[anaphylaxis]]
*Epidemiology<ref name=Hochstadter>Hochstadter, E. F., & Ben-Shoshan, M. (2013). Cold-induced urticaria: challenges in diagnosis and management. BMJ Case Reports, 2013, bcr2013010441. http://doi.org/10.1136/bcr-2013-010441</ref>
**M=F
**Most common in young adults (20-30 y/o)
**50% of patients improve within 5 years
*Cold stimulus can include<ref name=Hochstadter />:
**Handling cold items/objects
**Cold environments
**Swimming in or other exposure to cold water
**Ingestion of cold food/liquid

==Clinical Features==
[[File:Cold urticaria3.jpg|thumb|Uticaria on leg induced by cold stimulus.]]
*Localized or diffuse [[urticaria]] in response to cold stimulus
*Severe cases can present with [[angioedema]] or [[anaphylaxis]]

==Differential Diagnosis==
{{Acute Allergic DDX}}
{{Cold injuries DDX}}

==Evaluation==
*Cold Stimulation Test (CST) is main diagnostic test<ref name=Hochstadter />
**Ice cube (or other object at 0-4° C) placed on forearm for 5 minutes
**Test is positive if weal develops after 5-10 minutes of rewarming
*Consider lab testing:
**CBC if suspect infection
**C1 esterase inhibitor level in cases of angioedema
**ESR/CRP if suspect underlying autoimmune disease

==Management==
*[[Antihistamines]] (preferably second generation)
*Avoid cold exposure (wear protective clothing if unavoidable)

==Disposition==
*Generally may be discharged
*Admit if severe angioedema or respiratory involvement

==See Also==
*[[Cold injuries]]

==References==
<references/>

[[Category:Environmental]]