Inflammation / Inflamed inside; Discoloration; Swollen arm; Itchiness; Soreness 3in diameter from area; Necrotic area on her arm / Necrotic issue; A mass / She developed a 2x2cm mass in the site of the administration; Warm to touch; This spontaneous case was received on 15-Feb-2022 (reference number: SEQW23-00626), reported by other non-health care professional (consumer) and concerned a 62-year-old (61-year-old at the time of vaccination), female patient.  The subject's concurrent conditions included lupus, celiac disease, vitiligo, diabetes and hypothyroidism. The patient's concomitant medications included Plaquenil (hydroxychloroquine), unspecified insulin and Synthroid (levothyroxine sodium), all used for unreported indication.   On 28-Sep-2022, the patient was vaccinated with Flucelvax Quadrivalent (influenza vaccine inact sag 4; dose: 0.5ml, route of administration and anatomical location: not reported) for active immunization for the prevention of influenza disease caused by influenza virus subtypes A and B contained in the vaccine. The batch number reported was 350296, and expiration date: unspecified date in 2023.   On the same day, right after receiving Flucelvax Quadrivalent, from the time they took out the needle, it started the inflammation, itchiness, discoloration, and soreness of three inches (in) diameter from area.   On an unspecified date in 2022 (for three to four days, as reported), it continued, and the patient's site was warm to touch. The patient added she did not have a fever, just that the area got hot.  On unspecified date in 2022, the patient put Benadryl cream on it, and at some point, the patient developed a 2x2 big mass in the site of administration. The patient's arm was also swollen and developed necrotic area on her arm from all the inflammation. The patient described it as something akin to a hole in the site of administration (also reported as 'arm's muscle') concluding that it ate away at her muscle and there was a necrotic issue. The patient stated that the affected area looked like a spiderweb and inflamed inside. The patient also used hydrocortisone cream as treatment.   On unspecified days in 2022, the patient first went to see a primary care physician, then a rheumatologist followed by orthopaedist, an orthopaedic oncologist and finally a general surgeon, who ordered a biopsy. The patient had two magnetic resonance imaging (MRI) and the last one was showing the inflammation. It was reported that none of the patient's doctors had ever seen necrotic issue like that before. The patient was going to have a third magnetic resonance imaging (MRI) (reported as 'in three months from yesterday').  At the time of initial reporting, the patient had not recovered from the events of inflammation and 'swollen arm'.  The reporter assessed all the events to be related to Flucelvax Quadrivalent, as the patient stated that the immunisation resulted in a necrotic area on her arm from all the inflammation, and the patient's orthopaedic oncologist stated that the patient's injury was a consequence of the injection.   All events were considered to be serious due to seriousness criterion of medical significance. In addition, the event of 'vaccination site necrosis' was considered to be medically significant by a Physician within Seqirus' Pharmacovigilance and Risk Management Department.  Company comment: A 62-year-old patient was vaccinated with Flucelvax Quadrivalent. On the same day, right after receiving Flucelvax Quadrivalent, the patient experienced inflammation, itchiness, discoloration, and soreness of three inches diameter from injection site. Symptoms continued three to four days later, and vaccination site was warm to touch. The patient developed a big mass on site, necrotic area and her arm was swollen. The patient described it as something akin to a hole in the site of administration, concluding that it ate away at her muscle and looked like a spiderweb inflamed inside. The patient used benadryl and hydrocortisone cream as treatment. Causal role of the vaccine is assessed as possibly related for all events (vaccination site inflammation, vaccination site necrosis, vaccination site mass, vaccination site warmth, vaccination site pain, vaccination site discoloration, vaccination site pruritus and peripheral swelling), due to anatomical and chronological plausibility. Per collaboration criteria, presented information correspond to level 3 diagnostic certainty for cellulitis at injection site.; Reporter's Comments: The patient stated that the immunisation resulted in a necrotic area on her arm from all the inflammation, and the patient's orthopaedic oncologist stated that the patient's injury was a consequence of the injection.; Sender's Comments: A 62-year-old patient was vaccinated with Flucelvax Quadrivalent. On the same day, right after receiving Flucelvax Quadrivalent, the patient experienced inflammation, itchiness, discoloration, and soreness of three inches diameter from injection site. Symptoms continued three to four days later, and vaccination site was warm to touch. The patient developed a big mass on site, necrotic area and her arm was swollen. The patient described it as something akin to a hole in the site of administration, concluding that it ate away at her muscle and looked like a spiderweb inflamed inside. The patient used benadryl and hydrocortisone cream as treatment. Causal role of the vaccine is assessed as possibly related for all events (vaccination site inflammation, vaccination site necrosis, vaccination site mass, vaccination site warmth, vaccination site pain, vaccination site discoloration, vaccination site pruritus and peripheral swelling), due to anatomical and chronological plausibility. Per collaboration criteria, presented information correspond to level 3 diagnostic certainty for cellulitis at injection site.