Mohammed Abanemai

We describe an 11‐year‐old girl with PLACK Syndrome (peeling skin, leukonychia, acral punctate keratosis, cheilitis, and knuckle pads), who was found to have a novel homozygous variant in CAST, the pathogenicity of which was confirmed using blood‐derived RNA. There is no established treatment for PLACK syndrome. However, we demonstrate for the first time that this condition is associated with low levels of vitamin A and essential fatty acids, which prompted us to consider a potential treatment strategy. Indeed, we initiated this patient on intravenous lipid infusion (Vitalipid®; an emulsion of fat‐soluble vitamins and lipofundin‐MCT/LCT 20%) and the response was dramatic. Following the fourth monthly course of treatment, pruritis disappeared and the skin lesions showed remarkable objective improvement. PLACK syndrome is a very rare genodermatosis and only six families have been described to date with pathogenic CAST variants. This is the first report of an objective response to a therapeutic agent, which suggests that PLACK is a potentially treatable condition. The remarkable response we report and the relative safety of the intervention should prompt healthcare providers who care for PLACK syndrome patients to explore this as a potential treatment strategy in future studies.