To this end, a third promising type of biomarker is the presence and composition of the cutaneous bacterial flora; the skin microbiome. The term "cutaneous microbiome" describes the microbiological flora which colonizes human skin. There is evidence that the flora may be regulated in a time-, sex-, and medication-dependent manner. Indeed, describing and understanding the cutaneous microbiome is now the focus of intense research efforts to determine the role it may play in several skin diseases, including atopic dermatitis and bullous diseases.