You seem to have a delayed chemical hypersensitivity
(Type IV) agaist certain hair coloring chemicals and recommend you have a patch test
before using any more hair dyes.
For the moment, you need a systemic corticosteroid like prednisolone
1-2mg/kg BW for 15-20 days to control this reaction and also need to continue the Allegra
120mg until all of this is resolved.
As for the other 'skin allergy' I am not sure what it is, but a formal testing is recommended.