It is difficult to determine the exact cause of the burning sensation on the skin, especially since it appeared suddenly. It is recommended to take acetaminophen (Tylenol or other brands) or ibuprofen for the pain, unless you have any contraindications to the latter. If lesions appear, it is advisable to consult a pharmacist in person. If the pain worsens significantly or persists for more than 2 weeks without a clear explanation, it is important to see a doctor.