Gastrointestinal and hepatic manifestations in patients with generalised pustular psoriasis

Generalised pustular psoriasis (GPP) is a rare and severe form of pustular psoriasis. It is defined by persisting or relapsing macroscopically visible sterile primary pustules occurring on non‐acral skin and not within psoriasis plaques. Due to its rarity, there is a lack of randomised controlled trials on GPP and its associated gastrointestinal (GI) and liver disorders. In this article, we present a review of the GI and hepatic disorders associated with GPP. GPP is known to be associated with extracutaneous manifestations such as neutrophilic cholangitis. Abnormal liver function tests are reported in up to 90% of patients with GPP upon diagnosis. Less commonly, pancreatitis and gastrointestinal bleeding have been attributed to GPP. While a psoriasis registry with 7.5% prevalence of pustular psoriasis reported an association with viral hepatitis B and C, the true relationship remains to be elucidated as hepatitis B is endemic in Asia where GPP prevalence is higher. Common genetic mutations between GPP and conditions such as hepatocellular carcinoma and inflammatory bowel disease have been identified, explaining their possible associations and providing answers to potential therapeutic options for these conditions. A lack of recognition of these association may result in unnecessary withdrawal of efficacious and definitive drugs for the treatment of GPP. Understanding the characteristics of the associated GI and hepatic disorders will have important implications for targeting the appropriate therapeutics.