Fixed Drug Eruption - Symptoms, Causes & Treatment
Medically reviewed by Dr. Anand S. Urhekar, MD, MD Pathology, Clinical Advisor · Last updated July 2026
A distinctive drug reaction producing one or a few round, well-defined red-brown or violet patches that recur at exactly the same site each time the causative medicine is taken. Common culprits include NSAIDs, antibiotics such as co-trimoxazole and tetracyclines, and paracetamol.
Concerned this might be fixed drug eruption? Scan it with our AI skin checker or, for moles and pigmented spots, our AI mole checker. Free, no signup required.
Quick Answer
A fixed drug eruption is a round, sharply edged red-violet patch that reappears in exactly the same place each time you take a particular medicine, often within hours. It leaves a lasting slate-grey or brown mark. The diagnosis is made by the recurrence pattern; treatment is stopping and permanently avoiding the drug, plus topical steroid. Involvement of the lips, mouth or genitals needs urgent review.
Symptoms
- Round or oval sharply defined red, violet or brown patch
- Recurs at the identical site with each exposure
- Onset within 30 minutes to 8 hours of the dose
- Burning or itching
- Long-lasting grey-brown pigmentation after healing
Causes & Risk Factors
- NSAIDs, especially ibuprofen and naproxen
- Co-trimoxazole and other sulfonamides
- Tetracyclines and metronidazole
- Paracetamol
- Some laxatives and antimalarials
Treatment & Management
- Identifying and permanently stopping the causative drug
- Topical corticosteroid for the inflamed patch
- Oral antihistamine for itch
- Recording the drug as an allergy in medical records
- Dermatology referral for widespread or bullous forms
When to See a Doctor
See a doctor promptly if the patches blister, involve the lips, mouth, eyes or genitals, or if many lesions appear at once — generalised bullous fixed drug eruption can be serious.
Frequently Asked Questions
Why does the rash appear in the same spot every time?
Memory T-cells remain resident in that patch of skin after the first reaction. When the drug reappears in the bloodstream, those local cells reactivate — producing the same lesion in the same place.
Will the dark mark fade?
The residual grey-brown pigmentation is often long-lasting, sometimes a year or more, and can be permanent. Avoiding the drug prevents further episodes and further darkening.
Related Conditions
Medical References
Information on this page is sourced from and verified against reputable medical resources:
Concerned About Your Skin?
Upload a photo and get instant AI-powered analysis across 80+ skin conditions. Track your condition over time with photo timelines, or use our dedicated AI mole checker for moles and pigmented lesions.
Medical Disclaimer: This information is for educational purposes only and is not intended as medical advice. The content on this page should not be used to diagnose or treat any health problem. Always consult with a qualified healthcare professional for proper medical evaluation, diagnosis, and treatment of your condition.