Dear Dr. K,
Recently I got a severe leg abrasion when I had an accident on my motorcycle. I needed surgery to clean the leg and stop all the bleeding. Three days later my leg got red and swollen and itched. My surgeon gave me an antibiotic thinking it was infected. But the culture was negative, and the leg kept getting worse. Then, he gave me prednisone and the leg got better quickly. Any ideas?
Well, I’m no Dr. House, but since I know your food allergies include gelatin, I suspect you reacted to a hemostatic agent containing gelatin. “Hemostatic” means to stop bleeding and hemostatic agents are vital to surgeons. Gelatin is used in many of them because its’ protein structure provides a scaffold that promotes clot formation. It is available in two forms: a matrix (sponge, film or powder) or as a foam. Examples in common use today include: Surgifoam, Surgiflo, Gelfoam, Floseal, MeroPack, Thrombi-Gel, Gelfoam, and Optisphere. There are non-gelatin products available that are made from cellulose.
Unfortunately, the story doesn’t end there as you need to be aware of gelatin exposure in other medical settings. Some medical devices contain gelatin. Some vascular grafts contain gelatin as do some heart valve replacements. Some bone replacement implants contain gelatin and are used in both skeletal and dental products. IV fluids are generally safe but some of what are called colloid fluids (often used for patients in shock) contain gelatin. As it turns out, no colloid fluids in the USA contain gelatin, but gelatin containing fluids are frequently used in Europe.
Many medicines contain gelatin either to form the capsule (for example Advil Liqui-gels) or as a binder. Since the number of OTC and prescription drugs is so large, it is advisable to read labeling on any medication you plan to take. A few intraocular lens implants (used in cataract surgery) contain gelatin, but most do not.
Finally, some vaccines contain gelatin. Most notable is the MMR vaccine. There is an interesting side story to the MMR vaccine that is worth mentioning. Although allergic reactions to MMR are rare, when they do occur doctors initially thought it was due to egg allergy as the vaccine is prepared in an egg medium. But when these cases were more closely studied, it turned out that the gelatin, not egg, was the provocateur. Actually, children with egg allergy an receive MMR without any concern for allergic reaction. A few other vaccines may contain gelatin depending on the manufacturer: rabies vaccine, typhoid vaccine, yellow fever vaccine, and one type of flu vaccine.