I have a medium sized rash on forearm and it has four small open bumps or bites in it. it's is also dry and has fever. what do i do? what is it?

No way to know: Unfortunately, we can rarely diagnose a rash by a description. Many of the words that patients use to describe rashes are nonspecific. There are many 'doctor words' that aid in description: macule, papule, plaque, pustule, vesicle, and many, many more. Even when doctors describe rashes to one another, it is sometimes difficult to visualize the rash. A picture is worth a 1000 words.