Shar peis are known for their wrinkles, deep dermal folds that make them look like the Michelin Man. What causes the wrinkles? Hyaluronan the major compoment of mucin. Shar peis have a genetic defect that leads to excess production of hyaluronan, formerly called hyaluronic acid. Although the excess hyaluronan makes this breed of dog very cute, it does have a down side. When hyaluronan is broken down, the degredation products cause inflammation leading to a painful condition called mucinosis. Prednisolone will decrease production of hyaluronan but will also also decrease the wrinkles. Pictured below is Lulu, one of the most beautiful Shar peis I have ever seen. I hope she never gets mucinosis because I love her wrinkles!
Source: Zanna, G., et al., Hereditary cutaneous mucinosis in shar pei dogs is associated with increased hyaluronan synthase 2-mRNA transcription by cultured dermal firbroblasts. Vet Dermatol 2009;20(5-6)377-82.