skin bubbled,there was a bump under the skin; cringed and said that dupilumab syringe hurt; confirmed that they did not use a 45 degree; arm pain at the injection site after taking flu shot; took 400 mg loading dose, 200 mg every other week for atopic dermatitis with unknown weight; Initial information received on 19-Sep-2021 regarding a solicited valid non-serious case received from a consumer/non-hcp, in the scope of patient support program.   This case involves 10 years old male patient who had arm pain at the injection site after taking flu shot, cringed and said that dupilumab syringe hurt, skin bubbled, there was a bump under the skin and took 400 mg loading dose, 200 mg every other week for atopic dermatitis with unknown weight while receiving vaccine, while treated with vaccine INFLUENZA VACCINE and DUPILUMAB [DUPIXENT] with the use of medical device dupilumab pre-filled syringe.  The patient's past medical history, medical treatment(s), concomitant medication (s) and family history were not provided.   The DUPILUMAB PRE-FILLED SYRINGE component of the combination product (Single entity for initial use) has been identified with a device issue. It is unknown if the product was stored or used properly. The device was operated by the Patient Family Member or Friend.  On 03-Sep-2021, the patient started taking DUPIXENT (DUPILUMAB) 300mg/2mL injection at a dose of 400 mg once (Strength: 200 mg/1.14 mg)(loading dose once) subcutaneous, dosage was changed to 200 mg QOW (every other week) (with an unknown strength, batch number and expiry date) via dupilumab pre-filled syringe for Atopic dermatitis (product use issue) (same day latency). First time product used: Yes On 19-Sep-2021, the patient received a dose of suspect INFLUENZA VACCINE produced by unknown manufacturer lot number not reported.  On 19-Sep-2021 the patient developed a non-serious event 'arm pain at the injection site' (injection site pain) (latency: 16 days after dupilumab and same day after INFLUENZA VACCINE). On 26-Sep-2021 the patient developed a non-serious "cringed and said that dupilumab syringe hurt" (injection site pain) with a symptom of "confirmed that they did not use a 45 degree" (wrong technique in device usage process) 23 days following the first dose intake. On 24-OCT-2021 the patient developed a non-serious skin bubbled, there was a bump under the skin (injection site swelling) 1 month 21 days following the first dose intake of DUPILUMAB.  It was reported ''took a flu shot today and she does not know if that was a active or live virus and the consumer is having an arm pain a the injection site. Mother administered his dose yesterday (26Sep2021) at the back of the arm, it was hard for the needle to go in, attempted to administer a few times but would not go in then consumer's mother applied a little more pressure and finally went in the skin, consumer cringed and said that it hurt, confirmed that they did not use a 45 degree angle and that the nurse at the doctor's office instructed the consumer's mother to go straight in, and he had a flu vaccine 2 weeks and no issues with it. No treatment reported. Injection was administered to the left arm yesterday evening (24-Oct-2021), his skin bubbled, liquid came back out, there was a bump under the skin (injection site swelling), flattened out this morning, and consumer's mother just put a band aid on it as treatment reported, a wellness check this morning with the pediatrician and the bump was gone so events are resolved.   DUPILUMAB (DUPIXENT) was continued for injection site pain with syringe, injection site swelling and not applicable for product use issue and injection site pain with flu shot. Action taken with INFLUENZA VACCINE (INFLUENZA VACCINE) was unknown for injection site with flu shot, and not applicable for the rest events.  No corrective treatment was received for the events (confirmed that they did not use a 45 degree, cringed and said that dupilumab syringe hurt). It was not reported if the patient received a corrective treatment for the events (arm pain at the injection site after taking flu shot, took 400 mg loading dose, 200 mg every other week for atopic dermatitis with unknown weight).  At time of reporting, the outcome was Not Recovered / Not Resolved for the event arm pain at the injection site after taking flu shot, recovered for skin bubbled, there was a bump under the skin; was Unknown for the event took 400 mg loading dose, 200 mg every other week for atopic dermatitis with unknown weight and was Unknown for the event cringed and said that dupilumab syringe hurt.  Company causality: reportable for injection site swelling and not reportable for dupilumab; reportable for injection site pain and not reportable for dupilumab prefilled syringe; reportable for injection site pain and not reportable for INFLUENZA VACCINE   A Product Technical Complaint (PTC) was initiated on 27-Sep-2021 for dupilumab. Batch number; unknown, PTC number: 100161559. The reporter stated that the device pre-filled pen resulted in injection site pain. Sample was not received. Final investigation complete date: 25-Oct-2021. Summarized conclusion for this case is No investigation possible.    A Product Complaint (PC) was initiated on 25-Oct-2021 for dupilumab (lot/batch number: 0L610W and 31-Aug-2023) with PC number: 100169544.  The sample status of the PC was requested and awaited, and the PC was under investigation.   A Product Technical Complaint (PTC) was initiated on 27-Oct-2021 for dupilumab. Batch number; unknown, PTC number: 100170401. The sample was requested and awaited and PTC was set in process.  This suspected adverse reaction report is submitted and classified as a medication error solely and exclusively to ensure the marketing authorization holder's compliance with the requirements set out in the Directive 2001/83/EC and Module VI of the Good Pharmacovigilance Practices. The classification as a medical error is in no way intended, nor should it be interpreted or construed as an allegation or claim made by the marketing authorization holder that any third party has contributed to or is to be held liable for the occurrence of this medication error.  Additional information was received on 27-Sep-2021 by the consumer: Case updated from drug to device. Added events of injection site pain with a symptom of wrong technique in device usage process. Text amended.  Additional information was received on 27-Sep-2021 from quality department: PTC information added.  Additional information was received on 25-Oct-2021 from quality department: PTC results added.  Additional information was received from the patient via call center nurse and via the patient support program on 25-Oct-2021 and live follow up received on 27-Oct-2021 both processed together with the CSD of 25-Oct-2021: event added: skin bubbled, there was a bump under the skin. Clinical course updated and text was updated accordingly.  Additional information received on 25-Oct-2021 from patient and on 27-Oct-2021 from quality department: no new significant information received.  Additional information was received on 25-Oct-2021 from the quality department. PTC details were added with respect to 100169544. Strength was added. Text amended accordingly..