Her biggest fear is that the rash comes back.; Pain after 3rd vaccine; Discomfort after 3rd vaccine; Rash spread even more and it was itching; Rash got worst, Rash spreading into genital and upper thighs, Rash spread even more 5 hours after took medicine, Rash spread again despite taking oral steroid/ Rash around hip; Mild itching and had mild redness on both hands; Mild itching and had mild redness on both hands; This spontaneous case was reported by a consumer and describes the occurrence of PAIN (Pain after 3rd vaccine), DISCOMFORT (Discomfort after 3rd vaccine) and RASH (Rash got worst, Rash spreading into genital and upper thighs, Rash spread even more 5 hours after took medicine, Rash spread again despite taking oral steroid/ Rash around hip) in a 71-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 045B21A, 032B21A and 046B21A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     The patient's past medical history included Chemotherapy (Chemotherapy Pertuzumab IV,  Trastuzumab IV every 2 weeks) since 2020. Concurrent medical conditions included Breast cancer (on Chemotherapy) since 2020. Concomitant products included PERTUZUMAB from 2020 to an unknown date and TRASTUZUMAB from 2020 to an unknown date for Breast cancer.   On 14-May-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 11-Jun-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 08-Sep-2021, received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 10-Sep-2021, the patient experienced PRURITUS (Mild itching and had mild redness on both hands) and ERYTHEMA (Mild itching and had mild redness on both hands). On 11-Sep-2021, the patient experienced RASH (Rash got worst, Rash spreading into genital and upper thighs, Rash spread even more 5 hours after took medicine, Rash spread again despite taking oral steroid/ Rash around hip) (seriousness criterion medically significant). On 12-Sep-2021, the patient experienced DISCOMFORT (Discomfort after 3rd vaccine) (seriousness criterion medically significant) and RASH PRURITIC (Rash spread even more and it was itching). On 13-Sep-2021, the patient experienced PAIN (Pain after 3rd vaccine) (seriousness criterion medically significant). On 14-Sep-2021, the patient experienced FEAR (Her biggest fear is that the rash comes back.). The patient was treated with LORATADINE (CLARITINE) on 12-Sep-2021 for Adverse event, at an unspecified dose and frequency; DIPHENHYDRAMINE HYDROCHLORIDE (BENADRYL [DIPHENHYDRAMINE HYDROCHLORIDE]) on 12-Sep-2021 for Adverse event, at an unspecified dose and frequency; FAMOTIDINE (PEPCID [FAMOTIDINE]) on 12-Sep-2021 for Adverse event, at an unspecified dose and frequency; PREDNISONE (oral) on 12-Sep-2021 for Adverse event, at an unspecified dose and frequency and METHYLPREDNISOLONE SODIUM SUCCINATE (SOLUMEDROL) (intravenous) on 13-Sep-2021 for Adverse event, at an unspecified dose and frequency. At the time of the report, PAIN (Pain after 3rd vaccine), DISCOMFORT (Discomfort after 3rd vaccine), RASH (Rash got worst, Rash spreading into genital and upper thighs, Rash spread even more 5 hours after took medicine, Rash spread again despite taking oral steroid/ Rash around hip), PRURITUS (Mild itching and had mild redness on both hands), ERYTHEMA (Mild itching and had mild redness on both hands) and RASH PRURITIC (Rash spread even more and it was itching) was resolving and FEAR (Her biggest fear is that the rash comes back.) outcome was unknown.            The patient did not have any side effects after the first two doses. On Saturday night 11 SEP 2021, She started having a rash around her hip. On 12 SEP 2021, she got worst, the rash was spreading into genital and upper thighs.  She visited Urgent care and the doctor prescribed medications.She took the medications but 4 - 5 hours later the rash spread even more and it was itching. On same day they visited the ER again. This time they gave her Prednisone Pack, after taking the oral prednisone, she was a little better. On 13 SEP 2021 around 6-7PM, the rash spread again, and she had pain this time. At 10 PM same night, went back to the ER again and received IV solumedrol and fluids. On 14 SEP 2021, she is doing better.  She cancelled the chemotherapy infusion for 14 SEP 2021 and rescheduled it for next day. On 14 SEP 2021, at the time of reporting she was fine, and her biggest fear was that the rash comes back.  Other treatments reported included IV fluids.  This case concerns a 71 year-old, female with a history of breast cancer under chemotherapy, who experienced the unexpected serious events of pain, discomfort and rash (criteria: medically significant based on info avail and medical judgment). The events occurred between 2-4 days after the 3rd dose of mRNA-1273 Moderna vaccine. The benefit-risk relationship of mRNA-1273 Moderna vaccine in not affected by this report.; Sender's Comments: This case concerns a 71 year-old, female with a history of breast cancer under chemotherapy, who experienced the unexpected serious events of pain, discomfort and rash (criteria: medically significant based on info avail and medical judgment). The events occurred between 2-4 days after the 3rd dose of mRNA-1273 Moderna vaccine. The benefit-risk relationship of mRNA-1273 Moderna vaccine in not affected by this report.