The dramatic effect of dapsone on cutaneous bullous and pustular rheumatoid vasculitis on the sole.

Abstract

Dear Editor, Cutaneous rheumatoid vasculitis occurs in 0.7–5.4% of patients with rheumatoid arthritis (RA)1-3 and especially in those with severe and active RA. Depending on the level of the involved vessels, cutaneous features vary, including petechiae, purpura, livedo, nodules, digital infarcts, hemorrhagic blisters, ulcers, and gangrene.4, 5 We herein describe a case of cutaneous rheumatoid vasculitis presenting with a number of tense blisters, hemorrhagic bullae, tiny pustules and crusts on the bilateral soles and lower legs, which was successfully treated with dapsone. An 85-year-old woman suffering from RA for over 20 years, complained of skin eruptions on the soles, which had appeared 3 months previously and exacerbated prior to 1 week. She also had been diagnosed with interstitial lung fibrosis. Her RA had been treated with low-dose prednisolone (5 mg/day) and non-steroidal anti-inflammatory drugs. A physical examination revealed numerous hemorrhagic bullae, tiny pustules and crusts on the soles, as well as tense blisters on the lower legs (Fig. 1a,b). Although she had slight fever and complained of deterioration of joint pain of the knees and wrists, rheumatoid nodules and renal dysfunction were not present. Laboratory examination showed elevated C-reactive protein (CRP) (4.88 mg/dL), positive rheumatoid factor (157 IU/mL) and anti-nuclear antibody (1:160, homogeneous and speckled). A biopsy taken from the plantar hemorrhagic bullous lesion revealed a neutrophilic abscess in the epidermis, subepidermal bullae, edema and prominent neutrophil infiltration in the upper dermis (Fig. 1c,d). Polymorphonuclear leukocytes infiltration into the vessel walls, leukocytoclastic debris, fibrin deposition, altered collagen and extravasation of red blood cells were also seen in the mid-dermis (Fig. 1d). Results of the direct immunofluorescence tests were negative for deposition of immunoglobulin A (IgA), IgM, IgG and C3. Although dapsone (75 mg/day) had a dramatic effect over a 2-week period (Fig. 1e), the bullous lesions relapsed when it was discontinued. Therefore, dapsone was restarted at a low dose of 25 mg/day and continued thereafter to good effect. Cutaneous rheumatoid vasculitis occurs in patients with active and severe RA, and clinically presents on the trunk and extremities with symmetric erythematous papules, nodules, plaques, urticaria-like erythema and rarely, vesicles. Our case developed a number of tense blisters, hemorrhagic bullae, tiny pustules and crusts on the bilateral lower legs and soles. Histological features showed dense polymorphonuclear leukocytes infiltration in the interstitial tissues as well as blood vessel walls, fibrin deposition in the vessel walls, leukocytoclasis, and extravasation of red blood cells in the dermis, compatible with rheumatoid vasculitis.6 Another case with similar clinical features was previously reported, which was successfully treated by plasma exchange and immunosuppressive therapy.7 Effective treatments of cutaneous rheumatoid vasculitis include combinations of cyclophosphamide and corticosteroids, azathioprine, methotrexate, chlorambucil, dapsone and recently, infliximab. To date, only a few cases have been reported in which dapsone resulted in beneficial effects.8 Dapsone is a sulfone antibiotic with a property of anti-inflammatory action, and is used for autoimmune bullous diseases, neutrophil- and eosinophil-related disorders.9 Moreover, dapsone interferes with various neutrophil functions, and impairs neutrophil chemotaxis into the skin. In our case, dapsone showed a dramatic effect, and all of the eruption disappeared at 75 mg/day; however, the lesions relapsed after discontinuance of the drug. The soles are sites that are frequently susceptible to mechanical stress, and RA often presents with cutaneous manifestations with isomorphic response of the Köebner phenomenon.10 These mechanical stimuli may have contributed to the induction of rheumatoid vasculitis in our case. None declared. None.