arm was not only sore, red, hot, and swollen, it became itchy and a six inch diameter red circle appeared on my skin; a six inch diameter red circle appeared on my skin/arm was very sore (hot, red, swollen); started with myalgia, chills, sweating, headache - terrible myalgia (hair, teeth, skin hurt); started with myalgia, chills, sweating, headache - terrible myalgia (hair, teeth, skin hurt); experienced a sore arm, hot, red; started with myalgia, chills, sweating, headache - terrible myalgia (hair, teeth, skin hurt); started with myalgia, chills, sweating, headache - terrible myalgia (hair, teeth, skin hurt); started with myalgia, chills, sweating, headache - terrible myalgia (hair, teeth, skin hurt); experienced a sore arm, hot, red; started with myalgia, chills, sweating, headache - terrible myalgia (hair, teeth, skin hurt); a six inch diameter red circle appeared on my skin/experienced a sore arm, hot, red; This spontaneous case was reported by a patient and describes the occurrence of HYPERHIDROSIS (started with myalgia, chills, sweating, headache - terrible myalgia (hair, teeth, skin hurt)), ERYTHEMA (a six inch diameter red circle appeared on my skin/experienced a sore arm, hot, red), PRURITUS (arm was not only sore, red, hot, and swollen, it became itchy and a six inch diameter red circle appeared on my skin), FEELING HOT (experienced a sore arm, hot, red) and PERIPHERAL SWELLING (a six inch diameter red circle appeared on my skin/arm was very sore (hot, red, swollen)) in a female patient of an unknown age who received mRNA-1273.815 (SPIKEVAX 2023-2024) for COVID-19 prophylaxis. The occurrence of additional non-serious events is detailed below.     No Medical History information was reported.    On 29-Sep-2023 at 6:00 PM, the patient received dose of mRNA-1273.815 (SPIKEVAX 2023-2024) (unknown route) 1 dosage form. On 30-Sep-2023, the patient experienced HYPERHIDROSIS (started with myalgia, chills, sweating, headache - terrible myalgia (hair, teeth, skin hurt)), ERYTHEMA (a six inch diameter red circle appeared on my skin/experienced a sore arm, hot, red), FEELING HOT (experienced a sore arm, hot, red), TOOTHACHE (started with myalgia, chills, sweating, headache - terrible myalgia (hair, teeth, skin hurt)), PAIN OF SKIN (started with myalgia, chills, sweating, headache - terrible myalgia (hair, teeth, skin hurt)), PAIN IN EXTREMITY (experienced a sore arm, hot, red), MYALGIA (started with myalgia, chills, sweating, headache - terrible myalgia (hair, teeth, skin hurt)), CHILLS (started with myalgia, chills, sweating, headache - terrible myalgia (hair, teeth, skin hurt)) and HEADACHE (started with myalgia, chills, sweating, headache - terrible myalgia (hair, teeth, skin hurt)). On 01-Oct-2023, the patient experienced PERIPHERAL SWELLING (a six inch diameter red circle appeared on my skin/arm was very sore (hot, red, swollen)). On 02-Oct-2023, the patient experienced PRURITUS (arm was not only sore, red, hot, and swollen, it became itchy and a six inch diameter red circle appeared on my skin). On 03-Oct-2023, TOOTHACHE (started with myalgia, chills, sweating, headache - terrible myalgia (hair, teeth, skin hurt)), PAIN OF SKIN (started with myalgia, chills, sweating, headache - terrible myalgia (hair, teeth, skin hurt)) and MYALGIA (started with myalgia, chills, sweating, headache - terrible myalgia (hair, teeth, skin hurt)) had resolved. At the time of the report, HYPERHIDROSIS (started with myalgia, chills, sweating, headache - terrible myalgia (hair, teeth, skin hurt)), CHILLS (started with myalgia, chills, sweating, headache - terrible myalgia (hair, teeth, skin hurt)) and HEADACHE (started with myalgia, chills, sweating, headache - terrible myalgia (hair, teeth, skin hurt)) outcome was unknown and ERYTHEMA (a six inch diameter red circle appeared on my skin/experienced a sore arm, hot, red), PRURITUS (arm was not only sore, red, hot, and swollen, it became itchy and a six inch diameter red circle appeared on my skin), FEELING HOT (experienced a sore arm, hot, red), PERIPHERAL SWELLING (a six inch diameter red circle appeared on my skin/arm was very sore (hot, red, swollen)) and PAIN IN EXTREMITY (experienced a sore arm, hot, red) had not resolved.            Concomitant medication information was not provided.  On the previous Saturday morning, the patient experienced a sore arm, hot, red. Around 3 P.M on Saturday, the patient started with myalgia, chills, sweating, headache - terrible myalgia (hair, teeth, skin hurt). On Sunday morning, the patient's arm was very sore (hot, red, swollen) and the myalgia persisted throughout the day on Sunday. On Monday, the patient still had lingering myalgia and arm was not only sore, red, hot, and swollen, but it became itchy and a six inch diameter red circle appeared on the skin. On Tuesday, the myalgia was gone, but arm was still sore.  Treatment information was not reported.