It is an allergy due to repeated contact with your skin and a chemical or chemicals in the products (usually with gels it is acrylates, gluteraldehyde or formaldehyde which are the main culprits).
Fact is that an allergy from over exposure to products doesn't need to happen. Nail products should not touch the skin but only be used on nails and a free margin left around the application.
Sorry, there is no good news here ... Once allergic ALWAYS allergic .. in other words .. it will only get worse with continued exposure. It's gloves from now on if you work with the products and you should not be wearing them.
CND Brisa gels are hypoallergenic and do not contain the 3 chemicals listed above. You could also try a 'try me' kit of CND Retention+ monomer which many who are allergic to other acrylic monomers find they are not allergic to retention+.