<s>[INST] Our eighteen-month old nephew hit his head and briefly passed out a week ago. He was checked at A and E and there were no concerns. He then developed symptoms very like chicken pox which his GP is convinced he does not have. Is it possible that there is a connection to the concussion or are there viruses similar to chicken pox? [/INST] Hello,Welcome to HCM,Usually chicken pox presents with rashes and fever. If your nephew developed fever before the rashes came out, your kid most probably has chicken pox . If with no fever, you might be dealing with another entity (probably allergy).I am of opinion that it does noes not seems to be chickenpox , because in chickenpox lesions , rash leads to vesicles and then crust formation . Anyway if child is well you need not worry , get your child immunized for chickenpox , if not already done.Thank you. </s>