Liver test abnormalities in patients admitted for severe psoriasis: prevalence and associated risk factors.

BACKGROUND: Few epidemiologic data are available regarding biologic liver abnormalities during psoriasis flares.

OBJECTIVES: The aim of this study was to assess the prevalence of biological liver test abnormalities (LTA) in a psoriasis population and the risk factors associated with LTA.

METHODS: A retrospective cross-sectional study in four hospital dermatology tertiary care centres included patients admitted for severe psoriasis flare between 1st January 2010 and 31st December 2011. During the same period, a control population was selected comprising patients admitted for contact and/or atopic eczema. Data were collected on hospital records and biology software. LTA was defined as serum AST and/or ALT and/or ALP concentration above the upper normal limit (UNL) and/or GGT concentration above 2 UNL. Prevalence of LTA with 95% confidence intervals (95% CI) was compared between the psoriatic and control populations. Factors associated with LTA at P < 0.05 were considered for the final multivariate logistic regression model.

RESULTS: Two hundred and forty psoriasis patients and 96 eczema control patients were included. One hundred and fifty-five(64.6%) of the psoriasis patients were male, aged 55 years on average (±17.6); 192 (80.0%) had plaque-type psoriasis (PV) and 52 (21.6%) had localized (n = 32) or generalized (n = 20) pustular psoriasis (PP). Prevalence of LTA was 36% (95% CI, 30-42) in the psoriatic population, significantly higher than in controls (17%, 95% CI 9.5-25). Risk factors independently associated with LTA comprised PV (OR 3.79; 95% CI 1.48-9.65), PP (OR 3.80; 95% CI 1.40-10.25) and previously diagnosed liver disease (underlying hepatic steatosis, viral hepatitis or excessive alcohol consumption) (OR 3.88; 95% CI 2.02-7.45). No association was found with systemic antipsoriatic drug therapies.

CONCLUSION: In severe psoriasis, liver impacting comorbidities and/or specific psoriatic inflammation, the latter mostly in PP cases, more than drug-related liver toxicity, appears to predominantly account for LTA. Clinicians should be aware of this, to avoid unjustified withdrawal of useful systemic drugs.