Rosacea is a clinical pattern beginning and evolving in the genetically susceptible individual in response to a host of exposures. It produces a variety of clinical presentations, which vary over time and with age. Recently, many specific mediators of rosacea development have been described. A primary genetic cause for rosacea is suggested as single genes often control such mediators: enzymes, neuroendocrine transmitters, and cytokines are found in pathways to rosacea signs and symptoms. Currently, neither a specific cause nor a laboratory indicator of rosacea has been suggested. However, broadening interest in rosacea portends future increase in knowledge.