The skin microbiome is mainly comprised of commensal and mutualistic bacteria. Some commensal species can behave as pathogens under the right circumstances, and one of the most common examples of this is Staphylococcus aureus. This bacterium can damage multiple parts and systems of the human body, both directly and indirectly. The factors responsible for the pathogenesis of S. aureus are discussed in this article, along with its particular role in the skin disorder atopic dermatitis, shedding light on how bacteria can use complex strategies to survive in a host.