Medication Summary
Treatment of urticarial vasculitis is based on systemic effects of the disease, extent of cutaneous involvement, and previous response to treatment. For patients with cutaneous involvement only, antihistamines or nonsteroidal anti-inflammatory drugs (NSAIDs) may provide symptomatic relief. However, Jachiet et al report that antihistamines were therapeutically ineffective for treatment of hypocomplementemic urticarial vasculitis. [14]
If these agents fail, colchicine, hydroxychloroquine, or dapsone may be effective. If all other treatment modalities have failed or if the patient has systemic involvement, consider initiating treatment with glucocorticoids. If the patient requires long-term treatment with corticosteroids, consider every-other-day dosing of the steroid or the addition of azathioprine as a steroid-reducing agent. Response to newer agents, including mycophenolate mofetil [29, 30] and rituximab, has been reported in the literature. Rituximab-based treatment can provide higher response rates compared with corticosteroids and conventional immunosuppressive agents, which supports its use in relapsing, refractory, or severe disease. [14]
Antihistamines
Class Summary
Antihistamines may serve as an adjunctive agent to relieve the itching or burning associated with urticarial vasculitis. Given alone, they usually provide only symptomatic relief.
Hydroxyzine (Atarax, Vistaril)
Hydroxyzine antagonizes H1 receptors in the periphery. It may suppress histamine activity in the subcortical region of the CNS. Hydroxyzine can be used for symptomatic control. The recommended antihistamine for pregnant patients is diphenhydramine. Hydroxyzine has been used safely in children.
Diphenhydramine (Benadryl, Benylin, Diphen, AllerMax)
Diphenhydramine is used for symptomatic relief of symptoms caused by release of histamine in hypersensitivity reactions. In pregnancy, use 25-50 mg PO q6h prn.
Anti-inflammatory agents
Class Summary
These agents modulate the immune system to reduce inflammation.
Colchicine
Colchicine is an alkaloid extract that inhibits microtubule formation. It is often used for the treatment of acute gout. Colchicine has been reported effective for urticarial vasculitis. It concentrates well in leukocytes and reduces neutrophilic chemotaxis and motility. Histologically, urticarial vasculitis presents with neutrophil involvement; therefore, colchicine possibly is useful. However, drug's effect has not been proven in clinical trials.
Sulfone antibiotics
Class Summary
Sulfone antibiotics are used for infectious diseases (eg, leprosy); however, sulfones are effective in inflammatory diseases. The mechanism of action may involve inhibiting free radical formation by neutrophils. In most case reports, these medications are effective only in purely cutaneous forms of urticarial vasculitis.
Dapsone (Avlosulfon)
Dapsone is the preferred sulfone. Other sulfones must be metabolized to dapsone for their effect. The mechanism of action is similar to that of sulfonamides in which competitive antagonists of PABA prevent the formation of folic acid, inhibiting bacterial growth.
Dosing guidelines for dermatologic use have been well described in dermatitis herpetiformis. Most case reports about effects in urticarial vasculitis use dermatitis herpetiformis dosing guidelines. Dapsone has been used extensively in chronic bullous diseases of childhood.
Antimalarials
Class Summary
Like other medications used to treat urticarial vasculitis, antimalarials are believed to exert their effect by their anti-inflammatory properties. Antimalarials reduce neutrophilic chemotaxis. In addition, they increase pH in lysosomes, which may affect antigen presentation. This class of medications usually is effective only in cutaneous disease.
Hydroxychloroquine (Plaquenil)
Hydroxychloroquine is the preferred antimalarial agent because of its low toxicity and high effectiveness profile. It is usually well tolerated if carefully monitored by the prescribing physician. Therapy is required for 4-8 weeks before evaluating effectiveness.
Nonsteroidal anti-inflammatory agents
Class Summary
Nonsteroidal anti-inflammatory agents are most commonly used for relief of mild to moderate pain. The basis behind the use of indomethacin is empiric. It was used with some effectiveness on the cutaneous manifestations of the disease in several case reports.
Indomethacin (Indocin)
Indomethacin is the only NSAID reported effective in urticarial vasculitis. It is rapidly absorbed; metabolism occurs in the liver by demethylation, deacetylation, and glucuronide conjugation. Indomethacin inhibits prostaglandin synthesis.
Cytotoxic agents
Class Summary
Azathioprine may be used as a steroid-sparing agent once other therapeutic options have been exhausted. Measurement of thiopurine methyltransferase can help ensure safe and optimal treatment with azathioprine.
Azathioprine (Imuran)
Azathioprine is a purine precursor that affects the formation of adenine and guanine. This results in impaired DNA synthesis in immunocompetent cells such as lymphocytes, which are dividing rapidly during an inflammatory process. Azathioprine has a slow onset of action; it is rarely used as monotherapy.
Glucocorticoids
Class Summary
Glucocorticoids are often the treatment of choice. However, given their long-term adverse effect profiles, they are used only for significant cutaneous disease or systemic involvement. For long-term treatment, a combination of prednisone and another medication may be required.
Prednisone (Deltasone)
Although prednisone is most effective, adverse effect profiles preclude it from use as a first-line agent. Consider it only after failure of antihistamines, indomethacin, colchicine, dapsone, or hydroxychloroquine. Its effect on urticarial vasculitis likely is mediated by its anti-inflammatory effect. This class of medications decreases capillary permeability and inhibits the mitotic rate of lymphocytes.
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Raised erythematous wheals with postinflammatory hyperpigmentations suggest urticarial vasculitis.
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A low-power histologic image of urticarial vasculitis shows leukocytoclastic vasculitis with damage to the vessel wall and a neutrophilic infiltrate.
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A high-power view of the histology of urticarial vasculitis shows extensive fibrin deposition in the vessel walls. Surrounding the vessels is a mixed infiltrate predominately composed of neutrophils with leukocytoclasis.
