Erythema is a skin disorder that occurs when there is excess blood flow due to vasolidation. It causes redness and inflammation and is a symptom of several infectious and skin diseases. It can also appear after a radiological procedure, due to prolonged exposure to heat and, above all, the sun; and from insect bites.
It is difficult to identify a specific cause for erythema. In adults, the most common cause is the intake of medications such as penicillins, sulfonamides, and barbiturates; usually due to some allergy. It can also appear due to a radiological procedure or radiotherapy treatment.
In children it usually appears due to viral infection, especially the herpes simplex virus.
Types of erythema:
- Erythema nodosum or nodosum. Inflammation of the thick layer under the skin. Red or purple tender lumps (nodules) appear. In children it can appear due to an infection in the urinary system due to streptococcal bacteria. In adults, the cause is usually an infection caused by these bacteria or sarcoidosis.
- Erythema multiforme or polymorphous. Inflammation with the presence of red, raised, target-like lesions distributed symmetrically throughout the body.
- Erythema infectiosum or 'slap disease'. Rash on face due to parvovirus infection.
- Lupus erythematosus.
- Thermal erythema. It is caused by a superficial burn of the skin. It is the most common type of erythema.
- Acneic erythema. Red spots accompanied by acne. It appears mainly in preadolescence and adolescence.
- Erythema pernio or chilblain. Red spots, inflammation and itching that usually appear on the fingers and toes.
- Intertrigo. It appears due to friction and rubbing of the skin folds.
Signs or symptoms of erythema are:
- Redness of the skin.
- Inflammation.
- Itching.
- Fever.
- General discomfort.
- Joint pain.
- Skin lesions. (nodules, papules...).
- Bloodshot eyes.
- Dry eyes.
- Eye pain.
- Vision problems.
- Mouth ulcers.
Diagnosis is based on physical examination, description of symptoms, and a biopsy of the lesion to examine the tissue under a microscope.
Treatment will depend on the cause of the erythema. If the symptoms are mild, it could be treated with antihistamines. You can also apply cold cloths to the lesions. If the cause is the herpes simplex virus, it will be treated with an antiviral. Fever and discomfort are treated with painkillers such as paracetamol. Corticosteroids will treat the inflammation.
Mild forms usually improve in a period of two to six weeks; however, the erythema usually recurs.
Prevention depends on the type of erythema; In the case of parvovirus erythema infectiosum, the most important thing is to maintain good hygiene, especially of the hands. It is also key not to share food or drinks.
In the case of erythema multiforme, it helps to use sunscreen, avoid sun exposure, and wear protective clothing.
