Is There Another Form of Retainer / Invisalign Other Than Plastic?

Yes, there are a few ways to make retainers and your Dentist/Orthodontist should be able to easily explain the advantages and disadvantages of each (ie. Durability, Cleans-ability, Longevity, Cost and Cosmetics).

More importantly, you need to follow up and find out what is causing your symptoms.  Allergies to plastic can occur, but it may be something totally unrelated and requiring treatment.  Schedule an appointment soon, as you should stop wearing your retainer until you are sure of the cause of your problem, but this may lead to shifting teeth.   A Dental Professional is needed to first diagnose and then treat you quickly so you can enjoy your new smile.

Good Luck.

First of all you need to determine if you are indeed having a reaction to the plastic in the retainer.  Also make sure the plastic retainer that you have is manufactured buy invisalign and not a local dental laboratory.  This can help determine if the plastic retainer is that same material as your invisalign aligners.  As an alternative to "invisalign style" retainers your can use an acrylic retainer with a stainless steel wire or a wire bonded to the teeth permanently.  

This could be an allergic reaction as some patients may be allergic to the plastic retainer material, but a definite diagnosis in this venue is difficult. An allergic reaction can develop even if there was no similar reaction during the 15 months of Invisalign treatment. There are alternative types of retainers available such as a bonded retainer placed on the inside surface of  anterior teeth. I would definitely recommend discontinued  use of the retainer and scheduling with your treating dentist / orthodontist as soon as possible to have the condition properly diagnosed and treated.