LAUSR

Psoriasis is an autoimmune T cell-mediated disease with a mean prevalence in Europe and North America of about 2%. In recent years, a better understanding of its immunepathogenesis has led to the improvement of drug efficacy and safety for the treatment of moderate-to-severe forms. Nevertheless, treatment of psoriasis in organ transplant recipients (OTRs) is still a challenge. In fact, immunosuppressive or biologic drugs, frequently used in psoriatic patients, may increase the risk of infections and malignancies and this risk is even higher in OTRs compared with the general population. In this study, we report the case of a 50-year-old Caucasian male patient who presented a moderate-to-severe flare of plaque-type psoriasis after a liver transplantation for non-alcoholic steatohepatitis (NASH) which progressed to cirrhosis. After the transplant, the patient was in good clinical status and started an immunosuppressive regimen with tacrolimus 4 mg daily, mycophenolate mofetil 1440 mg daily and prednisone 20 mg daily. At a follow-up visit 6 months later, the patient showed erythematous plaques covered by lamellar scales on his legs, arms and trunk configuring a flare of plaque-type psoriasis with psoriasis area severity index (PASI) of 14, despite immunosuppressive regimen (Fig. 1a). He also presented involvement of difficult to treat sites such as face, genitals and nails. The patient complained about burning and itching which seriously impacted his quality of life; the Dermatology Life Quality Index (DLQI) questionnaire showed a score of 15 (range 0–30). Therefore, re-evaluation of the biological treatment of psoriasis was set up. Methotrexate and acitretin were excluded as unsafe treatments in liver-transplant patients. Cyclosporine was not considered due to the immunosuppressive regimen already in progress. In accordance with the transplant team, ustekinumab, a human monoclonal antibody targeting the p40 subunit of IL-12 and IL-23, was started at 45 mg subcutaneously initially, after 4 weeks, and then every 12 weeks. After 1 month of treatment, an improvement was observed with a PASI decrease from a score of 14 to 6 (Fig. 1b). The DLQI improved from a score of 15 to 3, and no side effects neither deterioration of transplanted organ were observed. After 2 months of treatment, the patient reached complete resolution of psoriasis without any side effects (Fig. 1c), maintained at a 6-months follow-up visit. Currently, there are no guidelines for treatment of moderate-to-severe psoriasis in OTRs and only scattered information on the use of biologics in conjunction with immunosuppressive regimen have been reported in the literature. An improvement of the disease, with no side effects, has been reported in five OTRs affected by psoriasis treated with etanercept (anti-TNFa drug) and in one patient treated with ixekizumab (anti IL-17 drug). To the best of our knowledge, this is the first case of psoriasis in OTRs treated with ustekinumab (anti IL-12/-23 drug) with a rapid and complete resolution of the disease without any side effects at 6-months follow-up. In conclusion, as biological agents become increasingly used for moderate-to-severe psoriasis, studies with larger cohort will be needed in order to generate guidelines for their use in treating patients with organ transplantation affected by psoriasis. Table 1 Characteristics of patients with gas gangrene secondary to an infected epidermal cyst