On Saturday night DS complained of feeling hot. He had iced water and didn't mention it again. Yesterday, when he got dressed we noticed he had come up in hives. He has a pre existing peanut allergy and was tested for other allergies but nothing else was found. He had definitely not had any peanuts and had only had marmite on toast and a ginger nut biscuit to eat. We gave him Piriton and the rash did not really go down but with honey cream as well, it stopped itching. This morning the rash has gotten worse and covers his torso front and back slightly puffy skin. He has a slightly runny nose which he has had on and off for a week but hasn't been unwell. Has been quite touchy but given the situation we didn't think much of it. Temperature is normal. Eating as normal. We had a roast yesterday and rice pudding. No peanuts anywhere in the ingredients or listings of items pre made (stuffing only). We did go out in the car yesterday to take items to my mother who is stuck inside but he stayed in the car. However, it is a new car which we collected two weeks ago. We have been inside other than that with only my DH going out for shopping trips etc infrequently (twice a week to capture missing items). My DS and I have not been out aside from this. Am I being unreasonable to worry that this is a symptom of corona virus, and what should I do if the hives don't go away despite giving piriton?