For The Last Few Days I Have Been Experiencing A

For the last few days I have been experiencing a very strange rash. I got a streak of red bumps originally on the inside of my wrist. That began soon after it seemed an insect had bitten that area. It itched terribly and I thought it was poison ivy because it caused bumps also. It is slowly fading now. But then I've had a very itchy rash on one of my shins that popped up soon after that. There are some streaks that are extremely red and look like lesions rather than the bumpy aspect of poison ivy. I have treated these areas for the itch with Cortisone gel, so the itch is under control. But I wonder if I need to see a dermatologist because this is strange and it has me wondering when and how these lesions might heal!