Bacteria-Associated Cytokine Storm Syndrome.

While viruses are considered the most common infectious triggers for cytokine storm syndromes (CSS), a growing list of bacterial pathogens, particularly intracellular organisms, have been frequently reported to be associated with this syndrome. Both familial and sporadic cases of CSS are often precipitated by acute infections. It is also important to note that an underlying precipitating infection might not be clinically obvious as the CSS clinical picture can mimic an infectious process or an overwhelming septicemia. It is important to detect such an underlying treatable condition. In addition, infections can also be acquired during the course of CSS due to the concurrent immune suppression with treatment. Optimal CSS outcomes require treating bacterial infections when recognized.CSS should always be suspected in patients presenting with a sepsis-like or multi-organ dysfunction picture. There are many criteria proposed to diagnose CSS in general, with HLH-2004 being the most commonly used. Alternatively, criteria have been proposed for CSS occurring in specific underlying conditions such as systemic lupus erythematosus (SLE) or systemic juvenile idiopathic arthritis (sJIA). However, waiting for many of these criteria to be fulfilled could lead to significant delay in diagnosis, and the physician needs a high index of suspicion for CSS in critically ill febrile hospitalized patients in order to properly recognize the condition. Thus, there should be diagnostic equipoise between CSS and infections, including bacterial, in this population. In this chapter, we discuss the more common bacterial precipitants of CSS with many of the cases being discussed in the pediatric age group.