Breath analysis as well as the detection of abnormal respiratory rate can provide important feedback on people's health status. In this contribution we propose a wearable radiofrequency identification (RFID) epidermal device consisting of a flexible open loop antenna, that enables an easy adhesion on the user's skin, coupled with a graphene oxide-based sensor sensitive to the water vapour. The graphene oxide sensor was characterised in reference conditions, while the communication performance of the antenna was estimated by electromagnetic simulations over a human head phantom as well as by means of measurements on a volunteer. Finally, the whole system was experimentally demonstrated to be capable of comfortably detecting the inhalation/exhalation cycles and abnormal patterns of respiration like the apnea and tachypnea conditions by measuring the changes in graphene oxide resistance.