Hidradenitis suppurativa on groin and buttocks; This spontaneous case was reported by a consumer and describes the occurrence of HIDRADENITIS (Hidradenitis suppurativa on groin and buttocks) in a 45-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 vaccination.    Co-suspect product included non-company product ADALIMUMAB (HUMIRA) for Hidradenitis suppurativa.    The patient's past medical history included Abscess operations (Jul 2021 and Sep 2021, patient had deroofing of the groin and buttocks three times.). Concurrent medical conditions included Hidradenitis suppurativa.   On 10-Mar-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 07-Apr-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. On an unknown date, the patient started ADALIMUMAB (HUMIRA) (Subcutaneous) Citrate Free. In July 2021, the patient experienced HIDRADENITIS (Hidradenitis suppurativa on groin and buttocks) (seriousness criterion medically significant). At the time of the report, HIDRADENITIS (Hidradenitis suppurativa on groin and buttocks) outcome was unknown.            No concomitant medications were reported. It was unknown if patient was enrolled in a COVID-19 Vaccine trial. This case was identified as part of a retrospective clean-up activity where certain emails received in the Moderna mailbox were missed to be booked-in  Company comment-This spontaneous case concerns a female patient aged 45 years with relevant  medical history of HIDRADENITIS SUPPURATIVA reported, who experienced the unexpected serious (medically significant) event of Hidradenitis that occurred on an unknown date (in July 2021)approximately 3 months after second dose of mRNA-1273 vaccination. Patient underwent deroofing of groin and buttocks procedure three times in July and September 2021. No further information on risk factors, clinical course and investigations was available in the report. Outcome of the event was not known at the time of report. Patient had received two doses of mRNA-1273 at an interval of 28 days. Relevant medical history remains a confounder to the event. The benefit-risk relationship of mRNA-1273 Vaccine is not affected by this report. Event seriousness assessed as per medical judgement.   Reporter did not allow further contact; Sender's Comments: This spontaneous case concerns a female patient aged 45 years with relevant  medical history of HIDRADENITIS SUPPURATIVA reported, who experienced the unexpected serious (medically significant) event of Hidradenitis that occurred on an unknown date (in July 2021)approximately 3 months after second dose of mRNA-1273 vaccination. Patient underwent deroofing of groin and buttocks procedure three times in July and September 2021. No further information on risk factors, clinical course and investigations was available in the report. Outcome of the event was not known at the time of report. Patient had received two doses of mRNA-1273 at an interval of 28 days. Relevant medical history remains a confounder to the event. The benefit-risk relationship of mRNA-1273 Vaccine is not affected by this report. Event seriousness assessed as per medical judgement.