Postoperative swelling can be dangerous condition

Clinicians should also be aware of primary acquired cold urticaria (PACU), an under-recognized cause of postoperative swelling with potentially serious consequences. A recent report of patients who had undergone oculoplastic surgery and developed progressive postoperative swelling attributable to PACU elucidates the importance of diagnosing this entity.¹ Cold urticaria is either primary or secondary with both localized and systemic, potentially fatal, forms.^2,3

Sample case

The differential diagnosis considered included: toxoallergic reaction, cold urticaria, and infection. She was admitted to the hospital, treated with intravenous antibiotics, antivirals, and eventually intravenous corticosteroids. Orbital CT imaging showed profound preseptal, facial, and cervical swelling but no localized abscess (Figure 1). Her white blood cell count and differential were normal. The swelling resolved over 1 week and all cultures remained negative. Three months later she underwent ptosis revision, and within 24 hours postoperatively she again developed unilateral swelling. Her ice packs were stopped and diphenhydramine and oral corticosteroids were given, resulting in full recovery within 3 days. Cold urticaria was diagnosed, which was confirmed by a cold stimulation test. Systemic work-up was negative for any secondary causes.

PACU can begin at any age, but the mean age of onset is 18 to 26 years, with a mean duration of approximately 6 to 9 years.^2,4-7 There is no obvious gender predilection and the natural history of the disease is quite variable, with spontaneous recovery possible.² Most patients, however, experience a more chronic course.⁴

The systemic work-up includes: complete blood count with differential; erythrocyte sedimentation rate; serum protein electrophoresis; and cryoglobulin and cryofibrinogen testing. Tests for antinuclear antibody, rheumatoid factor, infectious mononucleosis spot test, and syphilis serology are also indicated if there is a suggestive history.³ The major cause of secondary acquired cold urticaria is cryoglobulinemia, whether primary or secondary to malignancy.² The next most common category is infectious, which may follow mononucleosis, syphilis, or parasitic infections.

In addition to a thorough history, the cold stimulation test (CST) is necessary to confirm the diagnosis of PACU. The test involves placing ice in a plastic bag on the patient's forearm for 1 minute. After the ice is removed, the exposed area is observed for 5 minutes for development of a confluent wheal-and-flare reaction.³ If there is no response, then the test is repeated at a different location of the forearm at increasing intervals (such as 3 or 5 minutes) for up to 10 minutes.⁸