Thanks for posting your query.
You may have viral fever as the presence of rash suggest.
There may also be possibilty of bacterial infection but the exact diagnosis can be made only after examination of rash.
You should consult with physician and hematologist
and should go for blood culture
You should also consult with dermatologist
Monocef is a peniciliin and by causing platelet dysfunction
,it may also cause purpuras which appears to be just like rash.
You should take azithromycin and ofloxacin group medicines.
Dr. mayank Bhargava