Airbus Flight Attendant crew reported a fume event during descent which lasted until gate arrival. Captain was notified and medical assistance requested. After much delay Flight Attendants were transported to local hospital for evaluation.

Narrative

On takeoff; both the FA's (Flight Attendant's) and myself noticed a slight smell in the aft of the aircraft; but it dissipated; so we just thought it was the jet fuel or deicing fluid. We didn't notice any unusual smells during flight. On descent; the smell returned; a lot stronger. It could be smelled in the front of the Cabin; we did go up front and confer with one another to determine if we should call the pilots (it was below 10;000 ft.). We decided to notify them on landing; as the odor was the only concern. As we returned to our jumpseats; the odor got increasingly strong; a mostly a chemical smell (different from the normal jet fuel smell that is common on the Airbus on takeoff and landing). Both myself and the B Flight Attendant felt nauseated and the smell was irritating our throats. I was gagging and almost threw up; and the B Flight Attendant said her throat felt tight and she also felt nauseated. After we disarmed our doors; I went to the bathroom because I thought I was going to throw up. My head started throbbing and I felt very nauseated and throat felt tight. I called the Flight Deck to notify them of the incident. They didn't smell the same odor; but came back to assess; and then we all got off the aircraft so we could get some fresh air. We stood in the jetway; the B Flight Attendant and I kept feeling increasingly worse. My head felt foggy and I was very nauseated. The Captain suggested I use the pilot oxygen; as I was feeling pretty bad; (my eyes were closed but going back and forth uncontrollably). So I went into the Flight Deck and used the Pilot Oxygen. That did help a bit. After conferring as a crew and with the CSA's (Customer Service Agent); the CSA's called the paramedics. The A FA and the C FA made most attempts at the list of Air Quality contacts. Services wanted us to evacuate the jetway and get away from the aircraft; so we went into the terminal. As the paramedics evaluated us; we attempted on multiple phones to get in contact with MedAire. The A FA got a hold of someone first; and that person told the A FA that we each individually had to call on a separate phone call to speak with someone. The B FA & I waited on hold for 45 minutes; and were not successful in getting a hold of anyone to be cleared. In the meantime; the Chief Pilot gave the ok for us to be transported to the hospital (since we couldn't get a hold of anyone). This whole process of 'being cleared' to go to the ER took over an hour. Eventually the 3 Flight Attendants were transported to the Hospital by ambulance.