Swollen eyes, head ache, rashes.

Hello madam/sir.My sister (21 years) fell sick all of a sudden with a temperature of 102 degrees later she developed rashes all over body and she even compalined of severe head ache(in normal days too she has severe head ache).1 day after complaining about head ache her eyes got swelled very badly..we admitted her into hospital but the doctors are not able to figure out the exact cause of these multiple problems..they extracted some water from her spinal chord to knw if there are any problems associated with brain nd the report was normal they said..jst minutes before they took her to MRI scan(brain,eyes,throat)shes complaining of throat pain too from this morning..are MRI and the spinal test mandatory..i heard that these tests have some side effects..Could you please tell me the exact problem please are all these interlinked..shez not allergetic to any food...my parents and I are getting tensed seeing the deteriorating condition of hers..please guide us..