Is there a home biopsy that i can do when i break out in a rash in order for my doctor to test it? never break out at the doctor office to test.

Take Photos: A biopsy is a procedure that entails removing a tissue sample (in your case skin) & can only be performed by a trained medical professional. Rashes require visual inspection to diagnose & unfortunately diagnosing a fleeting rash can be challenging. Suggest you take photos or video at next outbreak & bring to your doctor for review. Also note duration, frequency, other features (eg.itching, etc).