Sulfa vs. Sulfites_ Checklist of Sulfa Medicine and Sulfite Meals

Though “sulfa” and “sulfite” sound related, the 2 chemical compounds are usually not associated. Subsequently, so will not essentially be allergic to the opposite simply since you’ve had a response to at least one.

Sulfites are chemical compounds which are usually used as preservatives and antioxidants in meals (stopping browning and spoilage). A sulfa allergy refers to an allergy to sulfonamide-containing medication (additionally referred to as sulfur medication). These medication have a sulfonamide group of their chemical construction.

This text will talk about the place sulfa and sulfites are discovered and what to keep away from for those who’re delicate to sulfa or sulfites.

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Sulfa Allergy

A sulfa allergy is an allergy to medication with a sulfonamide group as a part of their chemical construction. These might be antibiotics, diuretics (water capsules), eye drops, topical lotions, and different sorts of medication.

Sulfa-based antibiotics are generally used to deal with pores and skin, hospital-acquired, and fungal infections. Some researchers estimate that sulfa allergic reactions impression as much as 8% of people that use these medication worldwide.

Signs of a Sulfa Response

Sulfa allergic reactions can current in a large number of how, together with as a rash. Your response might vary from delicate to extreme.

Regardless of how your allergic reactions current, you need to seek the advice of a healthcare supplier instantly. An initially delicate allergic response can shortly progress to anaphylaxis, a extreme life-threatening response requiring emergency medical care.

A generalized flat, crimson rash, often known as maculopapular eruption, is the commonest symptom of a sulfa allergy, however you may additionally expertise the next signs:

Generalized itching ( pruritus )

) Hives ( urticaria ), by which the crimson, itchy rash develops into raised welts with a clearly outlined border

), by which the crimson, itchy rash develops into raised welts with a clearly outlined border Swelling of the face, lips, fingers, or tongue ( angioedema )

) Shortness of breath, which in extreme circumstances could also be an indication of anaphylaxis

Stevens-Johnson syndrome or poisonous epidermal necrolysis , which is a blistering rash that destroys the highest layers of your pores and skin and mucous membranes

Solar publicity can set off or worsen your rash. Discovering some shade and cooling your physique down with ice are some preliminary steps you possibly can take must you develop a light pores and skin rash.

Checklist of Medicine That Comprise Sulfa

In some individuals, sulfa medication may cause the physique to launch histamine, inflicting a systemic (body-wide) inflammatory response that may have an effect on a number of organs.

When you’ve got a sulfa allergy, you need to keep away from antibiotics equivalent to Bactrim or Septra (TMP/SMX, trimethoprim-sulfamethoxazole). Trimethoprim-sulfamethoxazole is essentially the most generally used sulfa antibiotic. As a result of sulfamethoxazole is commonly mixed with trimethoprim, any antibiotic with trimethoprim needs to be prevented.

Different sulfa antibiotics embrace sulfadiazine, Silvadene (silver sulfadiazine), AVC Vaginal (sulfanilamide), and sulfacetamide (present in over-the-counter and prescription topical merchandise).

Sulfonamide-containing nonantimicrobial brokers embrace a number of lessons of medication. Some healthcare suppliers will keep away from prescribing these to individuals with an allergy to sulfonamide-containing antimicrobials. Nevertheless, analysis has proven {that a} response is unlikely, in order that they may be prescribed. These medication embrace.

Sulfite Allergy

A unfavourable response to sulfites might trigger a real allergy (by which the immune system reacts to their presence) or a sensitivity (by which signs are displayed however there is not an immune system response).

Signs of a Sulfite Response

A real sulfite allergy normally results in asthma-like signs. Sulfite sensitivity might trigger gastrointestinal signs. Chances are you’ll expertise the next signs in case you have an immune response to sulfite:


Shortness of breath (usually related to bronchial asthma exacerbations)

Allergic rhinitis (runny nostril, sneezing, watery eyes)

Urticaria (hives)


If you happen to ingest sulfite in processed meals or white wine, it’s possible you’ll expertise gastrointestinal signs equivalent to bloating, diarrhea, indigestion, and vomiting, which is indicative of sulfite sensitivity, particularly if there aren’t any higher respiratory signs.

Meals and Drinks With Sulfites

In case you are a wine or beer drinker, chances are high you’ve got ingested some sulfites in your lifetime, as they’re naturally current in fermented meals. Many meals comprise sulfites, particularly processed meals, to stop spoilage.

Frequent meals that comprise sulfites embrace:

Dried fruits


Condiments equivalent to ketchup, mustard, and mayonnaise

Frozen shrimp

Potato chips

Bottled lemon or lime juice


Imported fruit juice and delicate drinks

Frozen pizza and pie dough

Canned and frozen vegatables and fruits

Of word, all of the aforementioned meals needs to be prevented in case you have an allergy, however white wine and dried fruits particularly needs to be prevented since they comprise essentially the most sulfites.

The Meals and Drug Administration (FDA) requires sulfites to be listed on meals labels if the meals incorporates greater than 10 elements per million (ppm). Examples of sulfites embrace:

Sodium sulfite

Sodium bisulfite

Sodium metabisulfite

Potassium bisulfite

Potassium metabisulfite

Sulfur dioxide

Sulfa vs. Sulfites

Sulfites are generally added to meals to protect them and are naturally current in fermented meals. In case you are delicate to or allergic to sulfites, test meals labels and ask restaurant workers in regards to the components within the meals. The FDA banned sulfites on contemporary vegatables and fruits in 1986.

Notably, sulfite is added to drugs equivalent to epinephrine, Thorazine (chlorpromazine), and dopamine to stop discoloration. Nevertheless, an epinephrine injection (equivalent to an EpiPen) needs to be administered even to an individual with a sulfite allergy if they’re experiencing anaphylaxis, as it’s wanted to save lots of their life.

Sulfa is generally contained in drugs and dietary supplements. There isn’t a check for a sulfa allergy, so individuals normally discover out that they’ve an allergy after an adversarial medical response to a drug, complement, or private care product.

Reactions to sulfa medication and sulfite develop inside one to 48 hours of ingesting the substance. Each sometimes resolve inside two weeks of stopping the offending agent. Discontinuation quickly after the looks of an itchy rash or hives might result in a decision of your signs. Antihistamines and corticosteroids might assist.

No therapy prevents sulfite reactions, so you will need to keep away from the triggering substances. Some healthcare suppliers might attempt a desensitization program for an allergy to sulfa medication, prescribing small however rising doses to enhance tolerance.

You should definitely report any identified or suspected allergic reactions to a healthcare supplier to allow them to keep away from prescribing drugs which may set off a response.


Sulfa drug and sulfite allergic reactions sound related in title however are two distinctly various things. Sulfites are generally present in packaged meals and wines, whereas sulfa is present in medicines (significantly antibiotics) and dietary supplements.

Sulfite allergic reactions normally current with asthma-like signs equivalent to wheezing and hassle respiratory, whereas sulfa allergic reactions sometimes current with a rash. See a healthcare supplier in case you have a response. Search emergency medical take care of a extreme response.

Realizing what triggers the allergy or sensitivity and avoiding it’s key to stopping additional reactions. Report any allergic reactions to your healthcare supplier. Test meals labels in case you have a response to sulfites.

A Phrase From Verywell

Sulfites are preservatives which will appear inconceivable to keep away from in case you have a sulfite allergy or sensitivity. This may be irritating, however consuming contemporary vegatables and fruits limits your sulfite consumption to a negligible quantity.

Sulfa allergic reactions are normally skilled early after taking drugs. At all times inform a healthcare supplier of a identified sulfa allergy.

Whether or not you have got a sulfa or sulfite allergy, let your loved ones members and pals know, and clarify to them the distinction between the 2, to allow them to make it easier to keep away from the substances (like drugs for sulfa and meals for sulfite allergic reactions) which will trigger you to turn out to be unwell.