Rash on the right side of her abdomen that spread and was warm to the touch [Rash]; Rash on the right side of her abdomen that spread and was warm to the touch [Localised feeling of warmth]; Redness [Redness]; This spontaneous case was reported by a consumer and describes the occurrence of RASH (Rash on the right side of her abdomen that spread and was warm to the touch [Rash]), FEELING HOT (Rash on the right side of her abdomen that spread and was warm to the touch [Localised feeling of warmth]) and ERYTHEMA (Redness [Redness]) in a 56-year-old female patient who received mRNA-1273.815 (SPIKEVAX 2023-2024) for COVID-19 immunisation.    Co-suspect products included non-company products TREPROSTINIL SODIUM (REMODULIN) injection for Pulmonary arterial hypertension and INFLUENZA VACCINE (FLU [INFLUENZA VACCINE]) for Influenza immunisation.    The patient's past medical history included Gastroenteritis viral (had viral stomach flu and was taken to the emergency room. ouctome was unknown at the time of COVID-19 vaccination.) on 05-Sep-2023 and Device failure (had to use a backup cassette) on 05-Sep-2023. Concurrent medical conditions included Pulmonary arterial hypertension. Concomitant products included BIFIDOBACTERIUM LACTIS (PROBIOTIC [BIFIDOBACTERIUM LACTIS]), CURCUMA LONGA (TURMERIC [CURCUMA LONGA]), PREDNISONE, LEVOTHYROXINE SODIUM (UNITHROID), FLUTICASONE FUROATE, UMECLIDINIUM BROMIDE, VILANTEROL TRIFENATATE (TRELEGY), TADALAFIL, CARVEDILOL, ATORVASTATIN, CYANOCOBALAMIN (VITAMIN B12 [CYANOCOBALAMIN]), METFORMIN, RABEPRAZOLE, OXYGEN, IRON, VALSARTAN, MAGNESIUM, CALCIUM, VITAMIN C [ASCORBIC ACID], SALBUTAMOL SULFATE (ALBUTEROL [SALBUTAMOL SULFATE]), FUROSEMIDE (LASIX [FUROSEMIDE]), MONTELUKAST, CETIRIZINE HYDROCHLORIDE, PSEUDOEPHEDRINE HYDROCHLORIDE (ZYRTEC-D), GUAIFENESIN (MUCINEX), ROSUVASTATIN CALCIUM (CRESTOR), AMBRISENTAN, HYDROCHLOROTHIAZIDE, SPIRONOLACTONE (SPIRONOLACTONE AND HYDROCHLOROTHIAZIDE), VITAMIN D2, VITAMIN B COMPLEX (B COMPLEX [VITAMIN B COMPLEX]) and EMPAGLIFLOZIN (JARDIANCE) for an unknown indication.   On 26-Aug-2022, the patient started TREPROSTINIL SODIUM (REMODULIN) (Subcutaneous use) .07 microgram/kilogram. On 15-Oct-2023, the patient received dose of mRNA-1273.815 (SPIKEVAX 2023-2024) (unknown route) 1 dosage form. On 17-Oct-2023, the patient received dose of INFLUENZA VACCINE (FLU [INFLUENZA VACCINE]) (unknown route) 1 dosage form. In October 2023, the patient experienced RASH (Rash on the right side of her abdomen that spread and was warm to the touch [Rash]), FEELING HOT (Rash on the right side of her abdomen that spread and was warm to the touch [Localised feeling of warmth]) and ERYTHEMA (Redness [Redness]). The patient was treated with MAGNESIUM SULFATE (EPSOM SALT) in October 2023 at an unspecified dose and frequency. At the time of the report, RASH (Rash on the right side of her abdomen that spread and was warm to the touch [Rash]) was resolving and FEELING HOT (Rash on the right side of her abdomen that spread and was warm to the touch [Localised feeling of warmth]) and ERYTHEMA (Redness [Redness]) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): In September 2023, Weight: 182.6 lbs. In October 2023, Weight: 183 lbs.     For mRNA-1273.815 (SPIKEVAX 2023-2024) (Unknown), the reporter considered RASH (Rash on the right side of her abdomen that spread and was warm to the touch [Rash]), FEELING HOT (Rash on the right side of her abdomen that spread and was warm to the touch [Localised feeling of warmth]) and ERYTHEMA (Redness [Redness]) to be related.    On an unspecified date in Oct 2023, the patient got a rash on the right side of her abdomen that spread and was warm to touch. The patient tried Epsom salt (magnesium sulfate) and warm water solution over the area, and it brought down the rash drastically. The patient had a tetanus shot scheduled for 20-Oct-2023 and was directed to wait until rash disappears in 1-2 weeks before getting another vaccine. The patient was further counselled to try cortisone 10 as directed on package which could also help with redness (erythema) and if it had any itching.