Abstract
Accumulation of neutrophils within the epidermis and formation of pustules represents a unique, however, ill-understood phenomenon in human skin. In this overview, we compare localized versus systemic pustular disorders. Localized pustules are mostly infectious and appear to be generated by the interaction of skin cells with Th17 cells and macrophages. IL-1β, IL-17 and TNF-α in concert stimulate IL-8 secretion by keratinocytes. This cutaneous defense circuit creates the ensuing pustular pathology. In systemic pustular disease, dendritic cells (DCs) are activated by TLR-mediated signaling. IL-23 secreted by myeloid DCs feeds the cutaneous defense circuit, which results in neutrophilic infl ammation and pustules, as seen in infectious pustules. The distinction between local and systemic infl ammation, leading to neutrophil migration into the epidermis appears to be helpful in improving understanding of these common disorders of the skin.
Financial & competing interests disclosure
The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.
No writing assistance was utilized in the production of this manuscript.