In 1991, Vignon-Pennamen and Wallach proposed a unifying and prescient concept of “neutrophilic disease” (ND) in the light of clinical observations: (1) numerous reports of clinicopathological symptoms overlapping the typical forms of ND, including subcorneal pustular dermatosis (SPD; Sneddon-Wilkinson disease); Sweet’s syndrome (SwS); pyoderma gangrenosum (PG) and erythema elevatum diutinum (EED); (2) extracutaneous manifestations of neutrophilic disease; (3) non fortuitous association with systemic diseases and (4) usual therapeutic response to corticosteroid and/or dapsone [1]. In their article, they reviewed and argued the rare cases of various organ involvement suspected to be related to ND and previously reported, generally one or two observations for each organ, including bones, liver, lymph nodes, spleen, lung and kidney. Almost a quarter century later, a large number of extracutaneous manifestations of ND have been reported and allow a clarification on the risk of organ involvement depending on type of neutrophilic diseases, mostly Sweet syndrome and pyoderma gangrenosum, and their treatment (Table 16.1).