A Jarisch–Herxheimer reaction can appear a short time after the onset of antibiotic therapy. Due to a massive destruction of pathogens, toxins are set free. These toxins cause a release of substances which support the inflammatory reaction (so-called mediators of inflammation). A Jarisch–Herxheimer reaction is characterized by flu-like symptoms, as fever, shivering fits, aching muscles and arthritic pain. It can be prevented or at least moderated by the administration of steroidsm (prednisolone) prior to the onset of antibiotic therapy.