Title: Sulfa allergies: Overview and what to avoid
Headings: What to know about sulfa allergies
What to know about sulfa allergies
Symptoms
Medications that contain sulfa
Medications to avoid
Sulfa vs. sulfite allergy
Complications
Anaphylaxis
Stevens-Johnson syndrome
Treatment
Outlook

Content: Sulfa allergies: Overview and what to avoid
What to know about sulfa allergies
Medically reviewed by Alan Carter, Pharm. D. — Written by Bethany Cadman on March 28, 2018
Symptoms
Medications
Sulfa vs. sulfite allergy
Complications
Treatment
Outlook
A sulfa allergy occurs when a person has an allergic reaction to drugs that contain chemicals called sulfonamides. Sulfa is a constituent of some antibiotics and other medications. Doctors and pharmacists use drugs that contain sulfa to treat many conditions, including skin disorders, eye infections, and rheumatoid arthritis. People should note that there is a difference between sulfa and sulfite despite their similar names. Sulfites are used as additives and preservatives in many wines and foods. Also, sulfa is different from sulfates and sulfur. Both sulfa medications and sulfite can cause allergic reactions, but these two conditions are not related. A person who has a sulfa allergy will not necessarily have a sulfite allergy, so there is no cross-reactivity.