Skin Manifestations Associated with Autoimmune Liver Diseases: a Systematic Review.

Autoimmune liver diseases, which include mainly autoimmune hepatitis, primary biliary cholangitis, primary sclerosing cholangitis, and the variant syndromes, are often associated with extrahepatic autoimmune diseases. However, the association with cutaneous diseases is less well described. In the present article, we provide a systematic literature review on skin manifestations linked to each of these four autoimmune liver diseases, excluding skin manifestations of systemic diseases. The association of autoimmune hepatitis with vitiligo is well known, with a particular striking association with type 2 autoimmune hepatitis, a condition occurring almost entirely in children and adolescents, much rarer and more aggressive than type 1 autoimmune hepatitis; probable associations are also identified with alopecia areata, psoriasis, and pyoderma gangrenosum. Primary biliary cholangitis is not linked to lichen planus as previously assumed, but to vitiligo, psoriasis and the very rare amicrobial pustulosis of the folds. The proposed diagnostic criteria for this latter condition include the presence of anti-mitochondrial autoantibodies, the serological hallmark of primary biliary cholangitis. The very strong association of primary sclerosing cholangitis with inflammatory bowel diseases hampers the search for an association with skin diseases, since inflammatory bowel diseases have a strong association with various dermatological condition, including neutrophilic dermatoses and erythema nodosum. Nevertheless, a probable association of primary sclerosing cholangitis with psoriasis is identified in this review. Variant syndromes, also called overlap syndromes, are likely associated with vitiligo as well, which is not surprising, since autoimmune hepatitis is a feature of these conditions and they may share regions of the MHC.