Alcohol, psoriasis, liver disease, and anti-psoriasis drugs

Over the last years, data have been accumulating regarding a possible association between alcohol and psoriasis. While it is still unclear whether alcohol misuse represents a true risk factor or merely an epiphenomenon of the cutaneous disease, a number of studies support the role of ethanol and its metabolites as triggering factors of psoriasis. A drinking habit also appears to exacerbate a preexisting psoriasis, and the magnitude of alcohol consumption may be related to both a higher incidence and severity of psoriasis. Evidence also shows that deaths from alcohol-related causes are significantly more frequent in patients with psoriasis than in normal controls. Alcohol consumption may adversely affect psoriasis through multiple mechanisms, such as increased susceptibility to infections, stimulation of lymphocyte and keratinocyte proliferation, and production of proinflammatory cytokines. Moreover, alcohol misuse can predispose to a greater risk of liver disease and potential drug interactions. Alcoholic and non-alcoholic liver diseases have both been found to be common in psoriatic patients. Tumor necrosis factor (TNF)-alpha, a key cytokine in psoriasis pathogenesis, has been found to have a crucial role in alcoholic hepatitis, and small preliminary studies have evaluated the effect of anti-TNF therapy in this condition. However, the use of anti-TNF-α drugs in alcoholic hepatitis is still controversial and needs to be further investigated. In this review, the relationship between alcohol and psoriasis will be reviewed and discussed, taking also into account recent findings related to liver disease and therapeutic implications.