Urticarial vasculitis was first reported by McDuffie in 1973. It is characterized by wheal-like rashes that persist for a long time and are accompanied by hypocomplementemia. Inflammatory mediators damage vascular endothelial cells, leading to vasculitic changes that manifest as leukocytoclastic vasculitis. The cause of the disease is unknown, but reports suggest it may be due to iodine allergy, repeated cold stimulation, or hypersensitivity vasculitis triggered by allergens such as viruses, bacteria, or Chinese Taxillus Herb insects.

bubble_chart Pathological Changes

The main manifestations are swelling of the endothelial cells of dermal blood vessels and the eyelid, with a significant presence of neutrophils around the vessels. Nuclear dust and extravasation of red blood cells can be observed, along with fibrinoid degeneration of the vessel walls. Direct immunofluorescence reveals deposits of Ig and complement in and around the vessel walls.

bubble_chart Clinical Manifestations

It is more common in middle-aged women and may be accompanied by irregular fever, followed by wheal-like skin rashes that can last for 24 to 72 hours or even several days without disappearing. The wheals may develop blisters and infiltration but do not become necrotic. After subsiding, they may leave pigmented spots or desquamation, accompanied by itching. Symptoms may also include joint pain and swelling in the limbs, swollen lymph nodes, and abdominal discomfort. In advanced stages, kidney damage may occur. Vasculitic urticaria is often an early symptom of dermatomyositis, allergic vasculitis, SLE, etc., so close monitoring of disease progression is necessary.

The peripheral white blood cell count is normal or increased, with an elevated proportion of neutrophils, rapid erythrocyte sedimentation rate, and a significant decrease in C₄.

bubble_chart Diagnosis

Wheal persisting for more than 24 hours accompanied by hypocomplementemia, with histological findings of leukocytoclastic vasculitis, can be diagnosed and differentiated from lupus erythematosus and chronic urticaria.

bubble_chart Treatment Measures

If antihistamines are ineffective, corticosteroids can be the first choice to prevent kidney damage, and dapsone can also be used for treatment. Chinese medicinals may include modified Four Wonderful Herbs Resting Hero Decoction and other treatments.