There have been reports of allergy to titanium. All metal implants release some ions into the body but allergies to titanium are rare. Small particles from the implant may have caused a foreign body reaction. Some patients with metal implants have mild skin rashes and some have had severe rashes that resolved after removal of the implant. All metallic alloys corrode in contact with body fluids---even titanium alloys corrode. Eventually, the corrosion products enter the circulation in the patient's body. The products of corrosion of metals combine with a patient's own proteins (haptens) which could eventually sensitize the patient against the specific metal e.g. titanium. When the patient's immune system is sensitized it then may attack the titanium implant because it perceives it as a foreign body. In sensitized patients their T-lymphocytes are directed against the titanium. Then they release enzymes that produce inflammation in the soft tissues which, in some patients, may cause a rash and eczema.
The only parts that are manufactured from non metallic materials and do not corrode or enter a patient's circulation are made from polyethylene and ceramic materials.
I recommend that you have a patch test where titanium salts are mixed with a non-allergic ointment and then applied to your skin and the reaction is observed after 48 hours. Then, if the patch test is positive then you should think about having the titanium replaced with a resorbable graft (if your surgeon agrees that this is appropriate, of course). If your patch test result is negative, I recommend you have a more expensive laboratory test to directly measure your T-lymphocytes' response on contact with titanium. This is a more specific and sensitive test than a patch test.
Medtronic manufactures the Mystique Resorbable Graft Containment Plating System which is made of complex sugars called Poly L-lactide and co-D L-lactide. The Mystique's cervical plate and screws are transparent so that reading X-rays after surgery is easier. Because it is natural there is usually no risk of allergy or infection due to a foreign object in the body which is sometimes the case with titanium appliances. It also reduces the difficulty in swallowing because the plate eventually dissolves. The fused disc is in the front part of the neck and the Mystique plate is placed behind the esophagus and trachea. The implant maintains the stability of the weak bony tissue during the healing period and then it is eventually absorbed by the body.
Contraindications are if the patient has an active infection or if the patient is allergic to barium sulfate.
I must worn you, however, that all implants have the potential for causing inflammation due to a foreign-body reaction.
It's worth a try since you seem to be having such a severe reaction. I recommend you give it a try.