What Causes Rashes On My Body And Private Parts?

hi doctor my baby boy is 18th month old and last night he got the fever and last night i gave him ibuprofen 2.5 ml but in the morning he got the rashes on his body like his lips swelling and eyes and his private part and after thet i gave hin hydroxizine for the allergy .but right now he has fever what medicine i gave him can you please tell me.