Many emerging studies have implicated the Janus kinase/signal transducer and 
activator of transcription (JAK-STAT) cytokine signalling mechanism in disease 
pathogenesis. This signalling pathway is involved in haematopoiesis and immune 
development. Mutations in genes regulating JAK-STAT signalling can cause common 
inflammatory disorders and myeloproliferative disorders. JAK and STAT inhibitors 
are new management tools for disorders such as myelofibrosis and rheumatoid 
arthritis. Evidence suggests that the cytokine components of the JAK-STAT 
pathways play a crucial role in common skin disorders, including psoriasis and 
atopic dermatitis. We present an overview for the clinical dermatologist of the 
significance of these signalling pathways in various skin disorders, and 
introduce the potential application of JAK and STAT inhibition as a new 
therapeutic tool in dermatology.