The spatiotemporal dynamics of inflammation provide vital insights into the understanding of skin inflammation. Skin inflammation primarily depends on the regulatory feedback between pro- and anti-inflammatory mediators. Healthy skin exhibits fading erythema. In contrast, diseased skin exhibits expanding erythema with diverse patterns, which are clinically classified into five types: circular, annular, arcuate, gyrate, and polycyclic. Inflammatory diseases with expanding erythema are speculated to result from the overproduction of pro-inflammatory mediators. However, the mechanism by which feedback selectively drives the transition from a healthy fading erythema to each of the five types of diseased expanding erythema remains unclear. This study theoretically elucidates the imbalanced production between pro- and anti-inflammatory mediators and prospective treatment strategies for each expanding pattern. Our literature survey showed that eleven diseases exhibit some of the five expanding erythema, thereby suggesting a common spatiotemporal regulation underlying different patterns and diseases. Accordingly, a reaction-diffusion model incorporating mediator feedback reproduced the five observed types of diseased expanding and healthy fading patterns. Importantly, the fading pattern transitioned to the arcuate, gyrate, and polycyclic patterns when the productions of anti-inflammatory and pro-inflammatory mediators were lower and higher, respectively than in the healthy condition. Further depletion of anti-inflammatory mediators caused a circular pattern, whereas further overproduction of pro-inflammatory mediators caused an annular pattern. Mechanistically, the bistability due to stabilization of the diseased state exhibits circular and annular patterns, whereas the excitability exhibits the gyrate, polycyclic, arcuate, and fading patterns as the threshold of pro-inflammatory mediator concentration relative to the healthy state increases. These dynamic regulations of diffusive mediator feedback provide effective treatment strategies for mediator production wherein skins recover from each expanding pattern toward a fading pattern. Thus, these strategies can estimate disease severity and risk based on erythema patterns, paving the way for developing noninvasive and personalized treatments for inflammatory skin diseases. Author summary: The spatiotemporal dynamics of inflammation provide vital insights into understanding inflammation. Healthy skin exhibits fading inflammation, while diseased skin exhibits expanding inflammation with circular, annular, arcuate, gyrate, and polycyclic patterns. Diseases with expanding inflammation are thought to be linked to an overproduction of pro-inflammatory mediators, but how does the mediator production selectively transition from healthy fading inflammation to five diseased expanding inflammation? We used a mathematical model incorporating production and diffusion of mediators in the skin to simulate the fading and expanding patterns. The model reproduced the five observed types of diseased expanding and healthy fading patterns. We found that the fading pattern transitions in the order of arcuate, polycyclic, gyrate, annular, and circular patterns with increasing production of pro-inflammatory mediators or decreasing production of anti-inflammatory mediators. Importantly, dynamic feedback between pro-inflammatory and anti-inflammatory mediators is responsible for their production balance and controls health-to-disease transition of skin inflammation pattern. This mechanism guides treatment strategies and helps skin recover from expanding patterns towards a fading pattern. This research can help estimate disease severity and risk based on inflammation patterns and has potential applications in noninvasive and personalized treatments for inflammatory skin diseases. [ABSTRACT FROM AUTHOR]