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Fixed drug eruption - Oral Mucosal Lesion
See also in: Overview,Cellulitis DDx,Anogenital
Other Resources UpToDate PubMed

Fixed drug eruption - Oral Mucosal Lesion

See also in: Overview,Cellulitis DDx,Anogenital
Contributors: Rajini Murthy MD, Elizabeth B. Wallace MD, Belinda Tan MD, PhD, Susan Burgin MD, Carl Allen DDS, MSD, Sook-Bin Woo MS, DMD, MMSc
Other Resources UpToDate PubMed


Fixed drug eruption (FDE) is a drug reaction manifested by cutaneous and/or mucosal lesions recurring at the same body site each time an individual is re-exposed to the culprit drug. In most cases, FDE develops within minutes to hours of exposure. The oral and anogenital mucosa are the most frequently involved body sites. The oral mucosa may be the only site of involvement or may occur in association with cutaneous and/or genital mucosal lesions.

Lesions begin as sharply demarcated, red or violaceous patches and are often 0.5 cm to several centimeters in size or larger. Occasionally, these lesions will form vesicles or bullae, and on the mucosal skin, they can present as erosions or appear similar to aphthous ulcers. They are often associated with symptoms of burning, but may also be painful or pruritic. The most common presentation is with a solitary lesion, but some individuals may develop multiple lesions. Healing with postinflammatory hyperpigmentation is less commonly seen after oral mucosal involvement.

Numerous drugs have been implicated in causing FDE. Studies have shown certain drugs appear to have a predilection for causing the eruption to occur in or near the mouth. Commonly associated drug classes for FDE in the oral mucosal region are also the most frequently seen culprit medications for FDE in general. These medication classes include antibiotics, in particular sulfonamides, trimethoprim, and tetracyclines, and NSAIDs, including naproxen, ibuprofen, and celecoxib. Other drugs implicated in FDE include amoxicillin, erythromycin, metronidazole, fluconazole, paracetamol (acetaminophen), cetirizine, hydroxyzine, methylphenidate, oral contraceptives, quinine, and phenolphthalein. A nonpigmenting variant is seen with pseudoephedrine.


L27.1 – Localized skin eruption due to drugs and medicaments taken internally

73692007 – Fixed drug eruption

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Drug Reaction Data

Below is a list of drugs with literature evidence indicating an adverse association with this diagnosis. The list is continually updated through ongoing research and new medication approvals. Click on Citations to sort by number of citations or click on Medication to sort the medications alphabetically.

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Last Reviewed:02/02/2021
Last Updated:02/16/2022
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Patient Information for Fixed drug eruption - Oral Mucosal Lesion
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Contributors: Medical staff writer


A fixed drug eruption, also known as a drug rash or drug reaction, is a skin condition caused by a medication. In a fixed drug eruption, red or brown patches appear at the same body site every time the individual is exposed to the reaction-causing drug. Sometimes, the rash will itch, burn, or blister.

Who’s At Risk

Drug rashes can appear on people of all ages, all races, and of both sexes.

Any medication can cause a drug rash. The most common types of medications that trigger a fixed drug eruption include:
  • Antibiotics
  • Anti-inflammatories
  • Barbiturates
  • Oral contraceptives
  • Quinine
  • Phenolphthalein (sometimes found in laxatives)

Signs & Symptoms

Fixed drug eruptions can appear as red or brown patches. Drug rashes may involve the entire skin surface, or they may be limited to one or a few body parts.

Itching is common in many drug rashes. However, if fever is present, the skin is tender, or the rash is on the membranes inside the mouth or genitals, a more serious skin condition may be present.

Self-Care Guidelines

To relieve the itching of a mild drug rash:
  • Take cool showers or rest cold washcloths on the rash.
  • Apply calamine lotion.
  • Take an over-the-counter antihistamine.

When to Seek Medical Care

For a widespread or severe drug rash, call your health care provider or 911, depending upon the severity of your symptoms.

Whenever you are started on a new medication and develop a rash, immediately tell the doctor who prescribed the medicine.

If you have difficulty breathing, rapid heart rate, or swelling of your tongue, lips, throat, or face, you need emergency care.


Your doctor may want to perform blood work to look for signs of an allergic reaction. He or she may want to examine a tissue sample of your skin to rule out other skin diseases.

The best treatment for a drug rash is to stop the medication that is causing it. It may then take 5-10 days to see an improvement in the skin and up to 3 weeks for the rash to disappear.

Note: Stopping a prescription medication should be done only with a doctor's guidance.

Prescription treatments that may be helpful include:
  • Oral antihistamine pills for itching.
  • Topical corticosteroid (cortisone) creams or lotions.
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Fixed drug eruption - Oral Mucosal Lesion
See also in: Overview,Cellulitis DDx,Anogenital
A medical illustration showing key findings of Fixed drug eruption : Lips, Tongue, Feet, Hands
Clinical image of Fixed drug eruption - imageId=1453376. Click to open in gallery.  caption: 'A close-up of a round bright red plaque with a central darker color.'
A close-up of a round bright red plaque with a central darker color.
Copyright © 2023 VisualDx®. All rights reserved.