Etanercept: overview of clinical experience in the treatment of psoriasis and psoriatic arthritis

Psoriasis is one of the most common skin diseases, affecting approximately 2–3% of the Caucasian population. Plaque psoriasis, the most frequent type, is characterized by sharply demarcated erythematous scaly plaques typically located at the extensor side of the arms and legs, the head and the lower back. Nail involvement such as pits and oil drops is commonly present. Approximately 20% of patients develop an affection of the joints (psoriatic arthritis) [1,2] and 40–60% of them show a progressive course resulting into severe deformation and debilitating erosive arthropathy [3,4]. In addition, psoriasis has been associated with disorders of the metabolic syndrome such as obesity, diabetes, dyslipidemia and cardiovascular disorder, indicating the systemic character of the disease [5–7]. A chronic and often life-long disease, psoriasis is associated with a significant physical and psychological burden affecting all facets of the patient’s life and, therefore, profoundly impairs their quality of life [8]. Additionally, psoriasis as well as psoriatic arthritis causes a huge socio economic impact [9–12]. All this underlines the high need for effective and safe long-term treatments. The invention of biologics augmented therapeutic options to a great extent and revolutionized treatment modalities. Therefore, several guidelines for systemic treatments of psoriasis have been developed [13–15]. Concerning psoriasis, biologics are regarded as second-line therapeutics in Europe. They can be used when other conventional systemic treatments are ineffective, contraindicated or cause adverse reactions. This is different in the USA, where biologics might be used as first line if systemic treatment is warranted [15]. Etanercept (ETA), the first approved biologic for the treatment of psoriasis in Europe, is now in use for psoriasis, especially psoriasis arthritis, treatment for nearly a decade and, therefore, a firmly established treatment.