Some people have a sulfa allergy and need to avoid medications containing sulfonamides.
Illustration by Joules Garcia for Verywell Health
What Are Sulfanilamides?
Sulfanilamides, also calledsulfonamides, are made through chemical reactions.
Illustration by Joules Garcia for Verywell Health
Some healthcare providers will avoid prescribing these to people with an allergy to sulfonamide-containing antimicrobials.
However, research has shown that a reaction is unlikely, so they might be prescribed.These drugs include.
Sulfa-based antibiotics are commonly used to treat skin, hospital-acquired, and fungal infections.
Some researchers estimate that sulfa allergies impact up to 8% of people who use these drugs worldwide.
Trimethoprim-sulfamethoxazole is the most commonly used sulfa antibiotic.
Because sulfamethoxazole is often combined with trimethoprim, any antibiotic with trimethoprim should be avoided.
People with HIV are at increased risk for experiencing allergic reactions to sulfonamide antimicrobials.
These are two separate types of allergies with no connection between them.
Your reaction may range from mild to severe.
No matter how your allergies present, you should consult a healthcare provider immediately.
An initially mild allergic reaction can quickly progress toanaphylaxis, a severe life-threatening reaction requiring emergency medical care.
The diagnosis is made based on your symptoms, physical examination, and medical history.
A sulfa reaction usually resolves within two weeks of stopping the offending medication.
Discontinuation soon after the appearance of an itchy rash or hives may lead to a resolution of your symptoms.
Antihistamines and corticosteroids may also be prescribed to relieve symptoms.
You may be able to take some medications with sulfa that are low-risk.
Summary
Sulfa allergies are usually experienced early after taking medications and typically present as a rash.
Once the offending medication is stopped, symptoms usually resolve within two weeks.
Antihistamines and corticosteroids can help relieve symptoms in the meantime.
See a healthcare provider if you have a reaction and seek emergency medical care for a severe reaction.
Always inform a healthcare provider of a known sulfa allergy to prevent future allergic reactions.
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