Circular RNA: A novel potential biomarker for skin diseases

•Circular RNA (circRNA) with a covalent closed continuous loop, the 3’and 5’ ends of which are normally joined together, can function as regulators to participate in different diseases.•Accumulating investigations have found that many circRNAs are abnormally expressed in skin disorders such as malignant melanoma, psoriasis and abnormal wound healing. Because circRNAs can participate in the occurrence and development of skin diseases through a variety of molecular mechanisms, and have special structural and functional properties (stability, specificity and sensitivity), they are promising in serving a biomarker for diagnosis, prognosis, and therapy of skin diseases.•The RNA modification and secondary structure of circRNA need further exploration, and the circRNA abundance in plasma or other body fluids will need to be detected in the future to determine their suitability as non-invasive biomarkers for the diagnosis or prediction of skin diseases. And the safety and reliability of circRNAs as biomarkers or therapeutic targets in skin diseases need more verification. Moreover, the standardization of bioinformatics tools and the establishment of skin-related circRNA databases are crucial.