Additional factors influencing the severity of psoriasis have been examined, such as alcohol consumption. Alcohol may enhance the production of inflammatory cytokines and cell cycle activators, which could lead to epidermal hyperproliferation. Although there is no generally recognized decisive cure for psoriasis, many treatments are commonly used to reduce the severity of symptoms and lessen their impact on the patient's quality of life. For moderate-to-severe psoriasis, phototherapy and topical and/or systemic therapies are the standard medical therapies. Examples include corticosteroids, emollients, tar, methotrexate, and cyclosporine. However, many of these treatments are associated with significant adverse effects. Some alternative systemic therapies include monoclonal antibodies, fumaric acid esters, vitamin D analogs, novel retinoids, macrolactams, and biologic immune modifiers such as anti-tumor necrosis factor (TNF) agents.