Paradoxical neutrophilic dermatosis induced by biologics and immunosuppressive drugs: A systematic review

Cases of biological and immunosuppressive drugs induced-Sweet syndrome and -pyoderma gangrenosum have been increasingly reported in the literature.
 We reviewed all reported demographical, clinical, histological, pathological and therapeutic features of paradoxical neutrophilic dermatosis secondary to biologics and immunosuppressant drugs. 42 articles were included, with a total of 84 patients. Twenty-nine patients (34.5%) developed paradoxical Sweet syndrome with a mean age of 39 and a male to female ratio of 1.4:1, most incriminated drug being azathioprine (62%). Fifty-five patients (65%) experienced paradoxical pyoderma gangrenosum with a mean age of 35 and a male to female ratio of 1:2.5, most incriminated drug being rituximab (76%). Clinical presentations of paradoxical neutrophilic reaction were mostly cutaneous with rare systemic involvement. Most regressed with drug discontinuation alone, and only a minority required the addition of topical or systemic steroids or cyclosporine or antibiotics. Paradoxical neutrophilic dermatosis secondary to biologics and immunosuppressant should not be underestimated especially with the increasing use of these drugs.