Depends. It depends on the condition. Usually one would like to biopsy an active lesion but sometimes even normal-appearing skin may show the disease condition.
Hi doctor, my dermatologist did a skin biopsy of a rash lesion when I was having drug eruption, can my doctor see whether I have herpes simplex1?
Yes/Can be diagnosed. There are many types and causes of skin rashes. Several types of inflammatory conditions of the skin, allergic reactions, and sometimes bacterial, viral or fungal infections can cause rashes on the skin. Insect bites can also be the cause of a rash on the skin. Have it evaluated by a professional and get the appropriate treatment. Read more...