Can you be allergic to insulin?

This week I saw a very interesting man in the hospital. He was concerned that he had an allergy to insulin and shared his story with me.

This man, in his 70’s, has been a diabetic for about five years. He was previously using pills for his diabetes, but his blood sugars became very high when he was ill with pneumonia, so he was placed on insulin for a period of time. He had a variety of strange symptoms, including flushing of the face and nausea.{{more}} After he stopped taking the insulin, the symptoms went away. He was later put on a different type of insulin, because his blood sugars became very high again. He had a similar reaction to this different insulin. The night before I was called to see him, he was given a different type of insulin again, and he became very sick, face flushing, vomiting, etc. The morning that I saw him, he was feeling tired, but much better. He had not had any insulin for 12 hours.

Does this man have an allergic reaction to insulin? I am not sure. He has several other illnesses that may contribute to his symptoms. In the past, I have only come across one other case of an allergy to insulin, and in that case the woman actually had a RASH when she used a specific type of insulin. She was able to switch to another type and did just fine.

I brought this up to you because, every now and then I have patients who ask me about the possibility of them being “allergic” to insulin, because they do not feel well while taking it. There are few issues to sort out regarding this question:

1) Is this really an ALLERGY (immune reaction) or an adverse effect (something, unpleasant happening, not true allergy)? It is important to figure that out, and this man I spoke with will be seeing an allergy specialist for specific testing to figure this out. Feeling bad does not mean allergy. By the way, blood sugars dropping “too fast” are not an allergy – instead it most likely means your insulin dose is too high or it was administered incorrectly. Having a red mark or itchy skin around where the insulin was injected COULD be a mild allergy, but the data shows that this usually improves over time, so that it will eventually stop happening. Severe reactions, such as you stop breathing after you receive a medication, are different, and should lead to you NOT using that medication again.

2) Are you allergic to INSULIN or the preparation/preservatives? Insulin that is used today is no longer from pork and cow, so that is not an issue. However, the insulin is combined with other proteins or chemicals, and you could have allergy to those. Having an allergy to insulin itself is extremely rare. Even having an allergy to the preservatives/preparation is uncommon, and estimated at less than one per cent when using the newer non-animal derived insulin.

So, for this gentleman, I asked that he stop using his insulin, start taking diabetes pills again instead (his kidneys were okay, so he could do that) and have special tests done by an allergist to figure out if this allergy was real. If you are concerned about possible allergy to insulin, of course, talk to your doctor about it. Please don’t just stop taking the medication and say nothing. It is very uncommon, so you most likely do NOT have an allergy, but it should be checked out anyway.

Until next week, stay safe and healthy Vincies!

Anita Ramsetty, MD endodocs@endocrinehelp.com

Medical Director Endocrine Care Group

www.endocrinehelp.com

Tel: 843-798-4227