I am 19 years old, 70 inches in height, and weight 185 lbs. I'm pretty healthy. I do not have any illnesses and am rarely sick besides the seasonal cold here and there. I did recently have poison ivy and was taking prednisone. Other than that, I take no medications daily. I have a large, raised, red circle on my tricep. It started out much smaller than it is now. It has only been three days but it has gotten larger and redder. It does not itch and I don't notice any spirals or any bite marks at the center. It is fairly painful and it is tender.