Fixed recurrent chromosomal erythema rash on the skin

2021-03-24 12:00 AM

The pathogenetic mechanism of erythema of chromosomal erythema fixates the allergic immune responses of types III and IV and is considered to be hypersensitive, recurring when the patient is re-taking the drug


Fixed recurrent autosomal erythema is a drug-induced skin reaction (drug allergy), usually oral medication, characterized by a circular, oval, oedematous erythematous lesion, sometimes blistering. The chromosome is in the receding phase, often recurring after the drug administration, fixed in some places (can add new locations), usually appearing a few hours after taking the drug, the appearance of lesions is often is heralded by a burning and stretching sensation in the place where the injury will later grow.

Aetiology and mechanism of pathogenesis

The most common cause of fixed chromosomal erythema is due to drug groups: colds, antibiotics, sulfamides, sedatives, and analgesics.

The pathogenesis of erythema has fixed allergic immune responses for types III and IV and is presumed to be hypersensitivity or recurrence when the patient is re-using a drug or has a chemical formulation close to it. .



Any position, but common in the genitals, around the mouth, around the eyes, can be found on the hands, body, face ...

When the disease relapses, lesions reappear in the previously affected locations, in addition to adding new locations.

There may be cases of damage to the oral mucosa, conjunctivitis, or herpes simplex analogue, urethritis.


Reddish skin (plaque), round or oval, 1 to several cm in diameter, slightly masonry, with clear boundary, bright red, dark red, purple, with a masonry that makes a red mark on a higher ridge. Sometimes on the surface there are water bubbles and come out. When it leaves behind, dark, brown, purple and black in color due to post-inflammatory pigmentation, it lasts a few months to several years.

The number of lesions is usually small, some clusters, rarely more than 10, but also rarely a lot of lesions or lesions in large masses 10-20 cm in diameter, sometimes similar to Lyell's syndrome.

When the mouth and genital slippery lesions cause pain.

Or recurrence, because patients do not know the disease is caused by drug allergies for the first time, so they use the drug to relapse, 30 minutes to 8 hours after taking the drug will appear lesions, lasting damage if still used. drug, after stopping the drug for a few days to a few weeks, the lesions disappear. The more times it recurs, the more damaged the chromosome and lasts for a long time (dark black color).

Mechanical symptoms

Itching, burning, sometimes this sensation is preceded by the site where the lesion will grow.

Systemic symptoms

Usually no systemic symptoms, fever, headache, and gastrointestinal disturbances are rare.

There may be a number of other clinical forms

The form of papules, urticaria, masonry, blisters, blisters (most common), can be haemorrhagic under the skin, ulcerative, pseudo atrophy.

Progression and prognosis

Usually resolves after a few weeks after stopping the drug, recurrence occurs several hours after taking the drug, the post-inflammatory chromosome lasts for several months, every year, the more times it recurs, the darker the lesion.


Implementing the quadrants

Relationship with the use of drugs.

Location of the number of lesions.

Injury nature.

Recurrence properties: relapse right at the site of the previous visit, chromosome persists after inflammation.

Endoderm, patch test in damaged skin with suspected substance responding in 30% of cases or trial of suspected substance (rarely used, should be avoided).

Differential diagnosis

Erythema multiforme.

Bleeding under the skin.

Genital erosions differentiate from herpes.

Stevens Johnson syndrome.

Distinguished from aphthosis, herpes.

Treatment and prevention


Identify and immediately stop the drug in question:

Topically apply skin relievers such as zinc oxide oil, or steroid cream.

Systemic use synthetic antihistamines, corticosteroids, vitamin C, calcium chloride by slow intravenous injection.

Post-inflammatory chromosome lasts several months or years and should be treated with hydroquinone.


Be cautious in using some drugs as mentioned above, especially colds, antibiotics, sulfamides, sleeping pills.

Identify and stop taking pathogens; If there is one problem, then advise the patient not to take the same drug again, other forms of the drug may also cause cross-reactivity.