My son is 3.6 yes old, 104cm height, 15.4 kgs weight. He developed a rash yesterday, it was looking like 2-4 small blisters/bumps which are pinkish and he was scratching it...today when I checked it has become big may or may not spreading out. It is also swollen in that area.please help what this could be..I'm really worried . 1) could this be virus( covid) related rash 2) could this be peteriases rosea related as he had it last year same time 3) what cream can we apply to soothe and reduce it.