Two cases of generalized pustular psoriasis: successful treatment with infliximab.

Abstract

Dear Editor: In case 1, a 41-year-old woman presented with a 3-year history of recurrent pustules on erythematous skin. The patient had been treated with methotrexate, sulfasalazine and cyclosporine for psoriatic arthritis and generalized pustular psoriasis (GPP) for 2 years. However, these treatments failed to yield satisfactory improvement. Physical examination revealed the presence of extensive erythematous patches with pustules over the entire body (Fig. 1A) and inflammatory arthritis was noted in the distal interphalangeal, sacroiliac and knee joints. We decided to use infliximab (3 mg/kg) to treat the GPP and psoriatic arthritis. The patient's pustular lesions cleared quickly within 48 hours after the first injection. After the second injection of infliximab (3 mg/kg), marked improvement in arthralgia was observed (Fig. 1B). She has since been receiving infliximab 3 mg/kg every 8 weeks as maintenance therapy. No recurrence of pustules or arthritis symptoms has been detected during 12 months of follow-up. Fig. 1 Pustular psoriasis in case 1 (A). Marked improvement was observed after the second injection of infliximab (B). In case 2, a 39-year-old woman with a 20-year history of plaque type psoriasis was admitted to our department for lower limb cellulitis. Rapid resolution of cellulitis was achieved after systemic antibiotic treatment (cefazolin 6 g/day). Three days after antibiotic treatment, she experienced abrupt onset of pustules on erythematous skin affecting more than 90% of body (Fig. 2A, B). She was initially treated with infliximab (3 mg/kg) combined with acitretin (30 mg/day) for pustular flares. Within 48 hours of the first infusion, the pustules were resolved, but diffuse erythema on the trunk and extremities remained (Fig. 2C, D). The patient received acitretin (20 mg/day) for maintenance after a single dose of infliximab. No relapse of the pustules has been noted, but mild psoriatic plaques have followed. Fig. 2 Generalized pustular papules on the entire body in case 2 (A, B). Near remission of a pustular eruption was seen 48 hours after infliximab infusion (C, D). Infliximab is a chimeric immunoglobulin G1 anti-tumor necrosis factor-α monoclonal antibody that is effective in treating moderate to severe psoriasis and psoriatic arthritis1. Several studies have documented a rapid improvement in recalcitrant GPP with infliximab (5 mg/kg)2,3. Because infliximab has a faster onset of action than that of other modalities including biologics, some researchers recommended that infliximab be used as the first-line treatment modality in patients with severe and acute GPP4. Both patients in the current study experienced dramatic resolution of pustules within 48~72 hours of infliximab infusion without any serious adverse events. Although the optimal infliximab dose and maintenance regimen for GPP has not yet been established, low dose (3 mg/kg) of infliximab showed excellent response in the current cases. In an earlier report, there was no significant difference between the 3 mg/kg treatment group and the 5 mg/kg treatment group for moderate to severe psoriasis5. However, more research is needed and we believed that low dose infliximab with or without acitretin may have an effect on acute GPP. Since infliximab appears to offer the advantage of rapid response and reduced morbidity, we may consider it extremely effective and well tolerated in adult patients with severe and acute GPP. However, since GPP tends to relapse frequently, large population studies are needed to evaluate the efficacy of maintenance infliximab therapy for GPP with recurrent pustular episodes.