Bullous ichthyosiform erythroderma (BIE) and non-bullous ichthyosiform erythroderma (NBIE) are rare congenital ichthyoses. Generalized pustular psoriasis (GPP) of von Zumbusch type is a rare and severe form of psoriasis marked by desquamative and pustular erythroderma associated with fever and altered general conditions. We report two adults with an ichthyosis typical of BIE in the first case and NBIE in the second, without any previous history of psoriasis, who presented with a severe and relapsing GPP of von Zumbusch type. Using current knowledge of the genetic relationship between psoriasis and congenital ichthyoses, we discuss the possibility of a common physiopathological link between congenital ichthyoses and GPP, and examine the possible therapeutic problems resulting from this pathological association, especially in BIE.