Caspase Recruitment Family Member 14 (CARD14, also known as CARMA2) is a scaffold protein that mediates NF-κB signal transduction in skin keratinocytes. Gain-of-function CARD14 mutations have been documented in familial forms of psoriasis vulgaris (PV) and pityriasis rubra pilaris (PRP). More recent investigations have also implicated CARD14 in the pathogenesis of pustular psoriasis. Follow-up studies, however, have been limited, so that it is not clear to what extent CARD14 alleles account for the above conditions. Here, we sought to address this question by carrying out a systematic CARD14 analysis in an extended patient cohort (n=416). We observed no disease alleles in subjects with familial PV (n=159), erythrodermic psoriasis (n=23), acral pustular psoriasis (n=105) or sporadic pityriasis rubra pilaris (n=29). Conversely, our analysis of 100 individuals with generalised pustular psoriasis (GPP) identified a low-frequency variant (p.Asp176His) which causes constitutive CARD14 oligomerization and shows significant association with GPP in Asian populations (P=8.4 × 10(-5); OR=6.4). These data indicate that the analysis of CARD14 mutations could help to stratify pustular psoriasis cohorts but would be mostly uninformative in the context of psoriasis and sporadic pityriasis rubra pilaris.Journal of Investigative Dermatology accepted article preview online, 23 July 2015. doi:10.1038/jid.2015.288.