Improvement of psoriasis during exenatide treatment in a patient with diabetes.

CONTEXT AND AIM: Psoriasis is an immune-mediated skin disorder frequently associated with obesity and type 2 diabetes (T2D). This report is of a clinically significant improvement in psoriasis lesions in a patient with T2D during treatment with a GLP-1 receptor agonist (exenatide). OBSERVATION: A 61-year-old male patient (BMI: 25.5 kg/m(2)) with T2D treated with metformin and sulphonylureas had also complained, since 1980, of extensive psoriasis that required multiple steroid-based treatments [Psoriasis Area and Sensitivity Index (PASI) score: 11]. In September 2008, his diabetes treatment was intensified with exenatide (Byetta(®)) to improve poor glycaemic control. The patient, as expected, lost weight and reduced HbA(1c) levels from 65 mmol/mol to 56 mmol/mol. However, after just 1 month of treatment with exenatide, the patient also reported a dramatic improvement in psoriatic plaques that was confirmed at the 1-year follow-up (PASI: estimated at 3-4). Withdrawal of exenatide was associated with weight gain, deterioration of glycaemic control and deterioration of psoriasis (PASI:>10). After reinstating exenatide treatment, the patient again reported a prompt improvement in psoriasis (PASI: 3.1). CONCLUSION: There was a major and rapid improvement in psoriasis in our patient with T2D following treatment with exenatide. A possible mechanism might be through direct modulation of the immune system by GLP-1 receptor agonists.