People with HUV syndrome have hives (urticaria) for at least six months and low levels of proteins (complement) in the blood. Complement levels can be determined through a blood test. Click here to visit the American Association for Clinical Chemistry's Web site Lab Tests Online to learn more about this test.
In addition to these major criteria, people with HUV syndrome must also have at least two of the following minor criteria:
Inflammation in the small veins of the dermis (diagnosed by biopsy)
Joint pain or arthritis
Inflammation in the eye (uvea or episclera)
Recurrent abdominal pain
The presence of anti-C1q antibodies (this test is not widely available)
Some people have urticarial vasculitis and low complement levels (hypocomplementemia), but do not meet diagnostic criteria for HUV syndrome. These individuals may be diagnosed as having HUV (where symptoms are limited to the skin), versus HUV syndrome.
Differential diagnoses for HUV syndrome include, Schnitzler's syndrome, Cogan's syndrome, and Muckle-Wells syndrome.