Hypocomplementemic urticarial vasculitis syndrome

Abstract

Hypocomplementemic urticarial vasculitis syndrome (HUVS) is an uncommon immune complex-mediated entity characterized by urticaria with persistent acquired hypocomplementemia. First described in 1973, HUVS is associated with several systemic findings including leukocytoclastic vasculitis, severe angioedema, laryngeal edema, pulmonary involvement, arthritis, arthralgia, glomerulonephritis, and uveitis. These manifestations should be present for at least 6 months. Laboratory findings include low complement levels of classical pathway, namely C1q, C2, C3, and C4. The disease marker is the serum presence of anti-C1q antibodies. Treatment, based on disease severity, involves corticosteroids and other immunosuppressive agents that have demonstrated some success. Patients may have significant morbidity and mortality, most commonly caused by chronic obstructive pulmonary disease and acute laryngeal edema.

How Not to Be Misled by Disorders Mimicking Angioedema: A Review of Pseudoangioedema

“…These characteristics, including the extracutaneous and systemic involvement, are all uncommon for typical angioedema. The appropriate management is determined by the severity of the disease, and may include combinations of antihistamines, hydroxychloroquine, corticosteroids and immunosuppression [36]. …”

Hypocomplementemic Urticarial Vasculitis in a Pediatric Patient

“…Unfortunately, renal involvement can be more severe in children [22,30]. In fact, the biopsy findings in these patients are indistinguishable from SLE [31]. Lung involvement may be non-existent at the time of presentation.…”

“…The activation of this cascade causes mast cell degranulation and generates anaphylatoxins. In addition, it upregulates chemokines and cytokines, which lead to deposition of immune complexes, increased vascular permeability, chemotaxis of inflammatory cells, and exacerbate tissue destruction and edema [16]. These events cause the clinical findings of urticaria and or angioedema.…”

Pseudoangioedema

“…The patients have been categorized into two subgroups: those with hypocomplementemia and those with normal complement levels [37][38][39]. Hypocomplementemic urticarial vasculitis syndrome is a rare entity associated with urticaria and persistent acquired hypocomplementemia.…”

“…There are also systemic findings such as renal, pulmonary, gastrointestinal, neurologic, rheumatologic and ophthalmic. Treatment is determined by severity and systemic involvement of the disease, including systemic corticosteroids and immunosuppressants [37][38][39].…”