Shareholic Button

November 18, 2014

Sulfa vs Sulfate vs Sulfur vs Sulfite Allergy

Having a "sulfa" allergy is quite common... What is uncommon is understanding that being "sulfa" allergic does not necessarily mean that one is also allergic to sulfates, sulfur, and sulfites. Also, when a patient states that have a sulfa allergy, they typically mean they have a "sulfonamide" allergy.

Why is this understanding of significance? It's because there is confusion whether a patient with a sulfa allergy can take sulfate containing medications safely. In the ENT world, that commonly means whether a patient can take cortisporin antibiotic ear drops which contains neomycin sulfate, polymyxin B sulfate, and hydrocortisone 10 mg (1%).

The answer is YES... a patient with a sulfa (sulfonamide) drug allergy can safely take drugs containing sulfate which is a completely different unrelated compound. They are NOT the same thing.

For that matter, sulfa allergic individuals should not be considered to be allergic to sulfur and sulfite containing substances either. Sulfite is a common preservative and can be found in small amounts in many fruits and vegetables (see below).

Sulfate allergy does not exist as far as I know, but it can act as a chemical irritant. Same goes for sulfur. Sulfite allergy does exist thru a non-immune mediated mechanism, but is exceedingly rare.

Here's a list differentiating common sulfa, sulfate, sulfur, and sulfite containing substances:

Sulfa (Sulfonamide)
• Bactrim antibiotic
• Sulfacetamide antibiotic eye drops
• Sulfasalazine used to treat IBS
• Thiazide diuretics
• Lasix diuretic
• Gyburide and Glipizide medications for diabetes

Sulfate Containing Drugs/Substances
• Cortisporin ear drops
• Heparin
• Dextran
• Morphine
• Soaps and Detergents (sodium lauryl sulfate)

Sulfite Containing Substances
• Lettuce, avocados, mushrooms
• Grapes, lemon, lime
• Wine
• Peppers, onions, pickles

Sulfur Containing Substances
• Fertilizer

So to summarize, people who react to sulfites do not need to avoid sulfates or sulfur.

People who react to sulfa do not need to avoid sulfites, sulfates or sulfur.


Fauquier blog
Fauquier ENT

Dr. Christopher Chang is a private practice otolaryngology, head & neck surgeon specializing in the treatment of problems related to the ear, nose, and throat. Located in Warrenton, VA about 45 minutes west of Washington DC, he also provides inhalant allergy testing/treatment, hearing tests, and dispenses hearing aids. He is also the chief medical officer of O2Labz, a medical and scientific 3D animation company.Google+ Christopher Chang, MD Bio


  1. I am allergic to sulfates; such as in shampoos, Neosporin, silvedene. even commercial aloe has sulfate in it, which burns like Hattie's! I use sulfate free shampoo and bar soap. bacitracin for burns and cuts.

    1. Absolutely concur. I told one allergist I was allergic to sulfates and was pooh poohed. He prescribed Elidel to treat my skin task. I used Elidel for two days. By the third day, I went from having a rash on 20% of my body to having a rash (and severe itching) on 60% of my body. Elidel has a sulfate base!!! Still haven't forgiven the bastard.

    2. Yep ! I agree was told that I could not have allergies to all three...prescribed iron tablets..ferocious rash over full body...Cataract surgery...warned nurse..given eye drops with sulfate..returned post surgery...cornea so swollen I was technically blind in eye...afraid to take albuterol inhaler..sulfate..told ok..could not be a problem.

  2. I am also allergic to all things sulfur, sulfa, sulfate, sulfide, etc. It is in fact possible. I spent a mission trip in Arizona and the sulfur in the water caused me to break out in hives and I couldn't drink the water because it caused blisters in my mouth and throat. I also had an anaphylactic reaction to the actual mineral sulfur in a class one time. People always roll their eyes and say it's not possible, but it definitely is. My reaction to neosporin was so bad when I was little they thought I had a flesh eating disease. I can't take a bath in Epsom salts (magnesium sulfate) because it causes me to break out in a rash. I'm legitimately allergic to sulfur.

  3. I too suffer with the following sulfa, sulfates, and all sulfonamides! Sulfa is found in diuretics for high blood pressure. I have to be careful what I use on my skin and hair. My outbreak was so bad due to a high blood pressure medication I was taking called tribenzor. After being on this medication for hypertension I had rashes all over my body, I itched all the time, was nauseated, and constantly in the bathroom. As soon as I stop taking my meds which contained the ingredients sulfa, using anything with a sulphate, sulfites, sulfonamides derivatives is one of the worse allergies any person can have. I had to read labels before I purchase personal care items and cleaning products. I wouldn't wish this allergy on anyone. I am waiting to see what will happen to the medication Lisinopril it also has sulfa as an ingredient used to control excess fluids from having high blood pressure! Please if you are allergic to sulfa in medications you might be allergic to other derivatives whether or not used medicinally, or personally. I don't care if you are an expert in the field of science or my opinion and from experience of knowing how my body has reacted to sulpha, and it's derivatives,I have concluded I am highly allergic to sulpha, and it's counterparts!

    1. So am I !!! Always take personal care to read all labels for food and meds ! Stay safe !

  4. I’m allergic to sulfa, sulfates, sulfur, and sulfites. I’ve had severe reactions to Heparin, Bactrim, Lasix, grapes, avocado, Cipro, and the list goes on and on. So I know that you can have allergies to all of these. And you have you watch out for sodium laurel sulfate being in some of your medications. You wouldn’t think that something used for cleaning would be put in medicine, but it’s put in as an inactive ingredient. I just found out the hard way a few days ago.


Please be aware that our office rarely if ever replies to comments. Click to read why

Banner Map

VIDEO: What Causes a Clogged Ear?