Patterns and Humans

Abstract

The appearance of spiral structures on the human tongue (geographic tongue) and skin (pathological rashes) are described. Affected and often migrating areas on the tongue can be bistable, patch-like fronts or waves. Pathological rashes with an expanding region of redness is often a result of an autoimmune disease in which the human immune system becomes hyperactive and attacks healthy tissues. In addition, we show a rotating spiral created by humans, which has been described as a reaction-diffusion waves in an excitable medium.