Allergie in My foot

Patient: Dears help plzzzzzzzzzzzz….2 days ago i was scratching my upper foot. tonight I found a large red patch (10 cm X 5 cm) with small red spots around (more than 12 spots). note that I didn’t have any unusual food neither drink nor medicament.please advice am very afraid..P.S.: the photo of my foot is uploaded here

Doctor: