breakout of her atopic dermatitisand it is very severe; severe redness; dryness; itchiness; redness on the flu/booster vaccine injection site; swollen skin on the flu/booster vaccine injection site; Initial information received on 26-Sep-2022 regarding an unsolicited valid  non-serious case received from a consumer/non-hcp.  This case involves "an approximately" 73 years old male patient who experienced redness on the flu/booster vaccine injection site, swollen skin on the flu/booster vaccine injection site and breakout of her atopic dermatitis and it is very severe while receiving vaccine INFLUENZA VACCINE and while treated with DUPILUMAB [DUPIXENT] via dupilumab pre-filled syringe.     The patient's past medical history, medical treatment(s), vaccination(s) and family history were not provided.   On 21-Sep-2022, the patient received a dose of suspect INFLUENZA VACCINE produced by unknown manufacturer lot number not reported. On 23-Sep-2022, the patient started taking DUPIXENT (DUPILUMAB) (strength: 300 mg/2ml) Solution for injection 2 pens loading dose 1X subcutaneous (with an unknown batch number) then inject 1 pen on day 15, then 1 pen every other week thereafter for Dermatitis atopic.  In SEP-2022 the patient developed a non-serious event "redness on the flu/booster vaccine injection site" (injection site erythema) (unknown latency) following the first dose intake and (unknown latency) following the last dose intake of DUPILUMAB. In SEP-2022 the patient developed a non-serious event "swollen skin on the flu/booster vaccine injection site" (injection site swelling) (unknown latency) following the first dose intake and (unknown latency) following the last dose intake of DUPILUMAB. On an unknown date the patient developed a non-serious event "breakout of her atopic dermatitis and it is very severe" (dermatitis atopic) (unknown latency) following the first dose intake and (unknown latency) following the last dose intake of DUPILUMAB. On an unknown date the patient developed a non-serious event "severe redness" (erythema) (unknown latency) following the first dose intake and (unknown latency) following the last dose intake of DUPILUMAB. On an unknown date the patient developed a non-serious event "dryness" (dry skin) (unknown latency) following the first dose intake and (unknown latency) following the last dose intake of DUPILUMAB. On an unknown date the patient developed a non-serious event "itchiness" (pruritus) (unknown latency) following the first dose intake and (unknown latency) following the last dose intake of DUPILUMAB. It was reported "patient reported a breakout of her atopic dermatitis and it is very severe. Pt (patient) reports severe redness, dryness, itchiness. patient had loading injection on friday 9/23/22. pt report of having redness and swollen skin on the flu/booster vaccine injection site that pt received on 9.21.22. pt will contact md office but pt would like us notify md (medical doctor) office."  Action taken with DUPILUMAB (DUPIXENT) and INFLUENZA VACCINE (INFLUENZA VACCINE) was unknown for all events.  It was not reported if the patient received a corrective treatment for the events (severe redness, dryness, itchiness, redness on the flu/booster vaccine injection site, swollen skin on the flu/booster vaccine injection site, breakout of her atopic dermatitis and it is very severe).  At time of reporting, the outcome was Unknown for the event redness on the flu/booster vaccine injection site, was Unknown for the event swollen skin on the flu/booster vaccine injection site and was Unknown for the event breakout of her atopic dermatitis and it is very severe.