Sweet syndrome induced by influenza vaccination; painful rash on his left neck and arm, hypersensitivity reaction; occasional fevers; arthralgias; erythematous papules and plaques on the lateral neck and left arm.; slight epidermal spongiosis with papillary dermal edema; diffuse dermal neutrophilic infiltrate; Initial information received on 09-Aug-2019 regarding an unsolicited valid serious case issued from a literature article.   This case involves a 41 years old male patient who experienced sweet syndrome induced by influenza vaccination slight epidermal spongiosis with papillary dermal edema, diffuse dermal neutrophilic infiltrate and diffuse dermal neutrophilic infiltrate, while he received vaccine INFLUENZA VACCINE (unknown manufacturer).  The patient had no significant past medical history. Concomitant therapy, medical treatment(s), vaccination(s) and family history were not provided.   On an unknown date, the patient received a dose of suspect INFLUENZA VACCINE produced by unknown manufacturer lot number not reported via unknown route.  On an unknown date, The patient developed a serious sweet syndrome induced by influenza vaccination (acute febrile neutrophilic dermatosis) along  with associated symptoms such as painful rash on his left neck and arm (rash) (1 day after latency), occasional fevers (pyrexia), arthralgias (arthralgia), erythematous papules and plaques on the lateral neck and left arm. (rash erythematous) (unknown latency) following the administration of INFLUENZA VACCINE. These events were assessed as medically significant. On an unknown date, The patient developed a non-serious slight epidermal spongiosis with papillary dermal edema (eczema) and diffuse dermal neutrophilic infiltrate (neutrophilic dermatosis) (unknown latency) following the administration of INFLUENZA VACCINE. The pathogenesis of sweet syndrome remains unknown but its association with underlying disease suggest hypersensitivity reaction.  Laboratory and diagnostic imaging: Laboratory evaluation was negative. Specific studies included CBC, CMP, ESR, ANCA, CRP, CPK, C3, C4, RF, ANA, anti-ENA, anti-CCP, antidsDNA, ACE, VDRL, and HSV/VZV. Chest x-ray was also negative. No vasculitis was identified and direct immunofluorescence was negative.  Final diagnosis was neutrophilic dermatosis, eczema and acute febrile neutrophilic dermatosis.  The patient was treated with triamcinolone cream, minocycline, and niacinamide. His cutaneous manifestations significantly improved, but his arthralgias were still present. Rheumatology subsequently started him on diclofenac.  The patient outcome is reported as Not Recovered / Not Resolved on an unknown date for sweet syndrome induced by influenza vaccination and arthralgias; as Recovering / Resolving for other events. (reported as cutaneous manifestations significantly improved, but his arthralgias were still present).  There will be no information available on the batch number for this case.; Sender's Comments: A 41-year-old male Patient experienced neutrophilic dermatosis, eczema and acute febrile neutrophilic dermatosis after vaccination.Time to onset is unknown with the role of vaccine. However, further information including patient's medical history, concomitant medications, previous vaccination and tolerance, would be needed to fully assess this case. Based on available information the role of vaccine cannot be assessed.