My dad is covered in rash all round his neck and head, please help me discover what this is?

you're most likely going to need to take him to the doctor. also, if you just say rash, no one can help you, becuase there are many types of rashes out there, so please be more descriptive. you might also be able to type in "rash on neck and head" and see what pops up. if you find a rash that looks similar, click on the pic, and see if it gives what rash it is and how to treat it.