So ive been randomly been itchy in my arm/forearm areas and when i scratch, it leaves red marks where i scratched. i dont really see hives or anything but its been happening for a while?

You're experiencing a type.of reaction called dermatographism. It's likely an allergic.response to something internal or external & its cause is very elusive. I recommend consulting an allergist for evaluation. Since your skin is in a state of hyperreactivity, I don't think skin testing for various allergies is an option though. Have you tried taking antihistamines for prevention of itchiness?

It is not uncommon, do not scratch because it makes itching worse. Apply cold compress or lidocaine cream 4-5% (OTC med) for itch relief as needed. Excessive scratching can create a secondary skin issue. Dry skin can be contributory so use moisturizer if your skin is dry. Take care.