Review Alcohol, psoriasis, liver disease, and anti-psoriasis drugs Nicoletta Cassano, MD, Michelangelo Vestita, MD, Doriana Apruzzi, MD, and Gino A Vena, MD 2nd Dermatology Clinic, Department of Biomedical Sciences and Human Oncology, University of Bari, Bari, Italy Correspondence Gino A. Vena, MD 2nd Dermatology Clinic University of Bari Policlinico Piazza Giulio Cesare 11 70124 Bari Italy E-mail: g.vena@dermatologia.uniba.it Conflict of interest: The authors declare no conflict of interest. Abstract 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-a 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. Introduction Psoriasis is a chronic, immune-mediated, multisystem, inflammatory disorder that has a complex multifactorial pathogenesis resulting from the interaction between genetic and environmental factors. The immunopathogen- esis of the disease is associated with a T-helper (Th)1 and Th17 response, with overproduction of proinflammatory cytokines, including interleukin (IL)-2, IL-12, IL-17, IL-21, IL-22, IL-23, interferon (IFN)-gamma, and tumor necrosis factor (TNF)-alpha. The course is chronic with flares related to endogenous and/or environmental trig- gers. In fact, several factors have traditionally been asso- ciated with psoriasis outbreaks, such as physical and psychological stresses, metabolic factors, smoking, admin- istration of peculiar drugs, infections, and traumas. While alcohol has been suspected to act as a promoting factor in various medical conditions, the actual data related to its precise role in psoriasis have been scarce and somewhat contradictory until recently. Specifically, even if many authors had long theorized a detrimental effect of alcohol on psoriasis, early reports showed con- flicting results. 1–4 However, hints indicating a significant correlation, derived from several large epidemiological studies, have been accumulating over the last years. In particular, large Scandinavian surveys found both a higher alcohol intake and an increased prevalence of alco- holism among psoriatic patients. 5,6 Detailing the tendency, women were found to drink more following the diagnosis of psoriasis, probably reflecting the negative impact of the skin disease on life quality. This evidence might represent a stress response, elicited by the patient in order to cope with the disease. Possibly, the rising incidence of alcohol misuse (= alco- hol intake over the recommended weekly limit) and addiction (= dependent drinking, when alcohol is both physically and psychologically addictive and it is possible to become dependent) in the general population has played a role in tightening the association with psoria- sis, 7,8 although it is difficult and impractical to quantify its exact influence. As a matter of fact, even if several studies have shown an accrued alcohol consumption in 1323 ª 2011 The International Society of Dermatology International Journal of Dermatology 2011, 50, 1323–1331