Dermatologic Manifestations of Urticarial Vasculitis Medication

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. 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^{[15, 16]} and rituximab, has been reported in the literature. However, larger studies have not been performed with these agents.

Class Summary

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)

Antagonizes H1 receptors in periphery. May suppress histamine activity in subcortical region of CNS. Can be used for symptomatic control. The recommended antihistamine for pregnant patients is diphenhydramine. Has been used safely in children.

Diphenhydramine (Benadryl, Benylin, Diphen, AllerMax)

For symptomatic relief of symptoms caused by release of histamine in hypersensitivity reactions.

In pregnancy, use 25-50 mg PO q6h prn.

Class Summary

These agents modulate the immune system to reduce inflammation.

Colchicine

Alkaloid extract that inhibits microtubule formation. Often used for treatment of acute gout. Has been reported effective for urticarial vasculitis. 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.

Class Summary

Used for infectious diseases (eg, leprosy); however, sulfones are effective in inflammatory diseases. 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)

Preferred sulfone. Other sulfones must be metabolized to dapsone for their effect. Mechanism of action is similar to that of sulfonamides in which competitive antagonists of PABA prevent formation of folic acid, inhibiting bacterial growth.

Dosing guidelines for dermatologic use have been well described in dermatitis herpetiformis. Most case reports about effect in urticarial vasculitis use dermatitis herpetiformis dosing guidelines. Has been used extensively in chronic bullous disease of childhood.

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)

Preferred antimalarial agent because of its low toxicity and high effectiveness profile. Usually well tolerated if carefully monitored by prescribing physician. Therapy is required for 4-8 weeks before evaluating effectiveness.

Class Summary

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)

Only NSAID reported effective in urticarial vasculitis. Rapidly absorbed; metabolism occurs in liver by demethylation, deacetylation, and glucuronide conjugation; inhibits prostaglandin synthesis.

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)

Purine precursor that affects formation of adenine and guanine. Results in impaired DNA synthesis in immunocompetent cells such as lymphocytes, which are dividing rapidly during inflammatory process. Has slow onset of action; rarely used as monotherapy.

Class Summary

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, combination of prednisone and another medication may be required.

Prednisone (Deltasone)

Although is most effective, adverse effect profiles preclude it from use as a first-line agent. Consider only after failure of antihistamines, indomethacin, colchicine, dapsone, or hydroxychloroquine. 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.