Do you suffer from a red ring on your skin that started as a red dot and slowly expanded into a ring? You may be suffering from erythema annulare centrifugum, abbreviated as EAC, which is considered a reaction pattern or skin hypersensitivity reaction to a variety of underlying causes. The presence of a red ring on the skin does not always mean that you have been bitten by a tick.
- What is erythema annulare centrifugum?
- Causes of erythema annulare centrifugum
- Symptoms: red ring on skin
- Examination and diagnosis
- Treatment of erythema annulare centrifugum
What is erythema annulare centrifugum?
Erythema annulare centrifugum, abbreviated as EAC, is thought of as a reaction pattern or skin hypersensitivity reaction to a variety of underlying causes. However, despite investigation, no cause is often found. Erythema annulare centrifugum is actually a descriptive term. Erythema stands for ‘redness’, annulare for ‘ring formation’ and centrifugum for ‘from the center’ or ‘spreading in all directions’. This is a red, ring-shaped skin lesion that spreads from the center. The condition is seen in both men and women, more commonly in adults than children. Some studies indicate that it occurs (slightly) more often in women.
Ringworm / Source: ProjectManhattan, Wikimedia Commons (CC BY-SA-3.0)
Causes of erythema annulare centrifugum
Often no specific cause for the skin abnormality(s) is found. However, erythema annulare centrifugum is associated in the literature with the following conditions:
- Infections with bacteria, fungi, parasites and viruses, such as tuberculosis (TB), sinusitis (sinusitis), candidiasis and tinea (ringworm);
- Drugs: amitriptyline, cimetidine, cotrimoxazole, finasteride, gold salts, hydrochlorothiazide, hydroxychloroquine, ibuprofen, estrogens, penicillin, piroxicam, salicylates and spironolactone;
- Antigens in food, usually blue cheese or (raw) tomatoes;
- Recurrent or chronic appendicitis (appendicitis);
- Urinary tract infection;
- Thyroid diseases, such as hyperthyroidism (overactive thyroid gland), Hashimoto’s disease;
- Autoimmune diseases such as rheumatoid arthritis, lupus erythematosus, Sjögren syndrome;
- Cancer, including Hodgkin lymphoma (with symptoms such as enlarged lymph nodes, fever and fatigue), lung cancer, breast cancer, ovarian cancer and prostate cancer.
Consultation with the doctor / Source: Syda Productions/Shutterstock.com
In these situations, erythema annulare centrifugum may ‘blanch’ when the underlying cause is treated, or the drug causing the skin abnormality is stopped. However, never stop taking a medicine without consulting your doctor.
Symptoms: red ring on skin
Erythema annulare centrifugum usually begins as a small raised pinkish-red spot (or bump) that gradually enlarges, spreading in all directions and taking the shape of a red ring, while the central area returns to its original color although there may be a temporary dark discoloration of the skin may remain. There is often some flaking at the edge. The red ring may enlarge slightly every day, on average about 2-5 mm, until it reaches a diameter of about 6-8 cm. Sometimes it does not take the shape of a complete ring, but takes an irregular, jagged shape. The lesion may also take the shape of a half ring or horseshoe shape. It may involve one or more lesions. The spot may disappear spontaneously after a few weeks, but it can also be present in varying degrees for many months and even years. Erythema annulare can occur on any part of the skin, but the trunk, face, arms and thighs are preferred locations. Usually no other complaints occur, but in some people it is accompanied by mild itching.
Blood collection / Source: Istock.com/anna1311
Examination and diagnosis
The diagnosis can be made directly, but microscopic tissue examination (a biopsy) is also necessary to make the correct diagnosis. There are more skin diseases that can take the shape of a ring, such as a tick bite. At the place where a tick has attached itself, roughly half of the people develop a characteristic red spot within two days to four weeks, which gradually expands into a pale red ring, which is lighter in color in the middle, with a diameter of about 15 centimeters. This spot is called ‘erythema migrans’. The doctor may also look at some skin flakes under a microscope to see if they contain hyphae. A fungal infection can also be ring-shaped (ringworm). Sometimes it is indicated to do additional research (for example blood tests), and if there are complaints that indicate an underlying disease or infection, further research will be done.
Treatment of erythema annulare centrifugum
If there is an underlying disease, this will need to be treated. Then the skin abnormalities will also disappear. However, often no cause can be found. In that case, treatment is in principle not necessary, because the erythema annulare will disappear on its own sooner or later. The spots remain visible for some time, after which they disappear spontaneously. However, keep in mind that it can take months to years for the stains to resolve. On average, it takes about a year for the spots to disappear completely. In case of severe redness or itching, the spots can be temporarily treated with a mild corticosteroid cream. This will have to be prescribed by your GP.
read more
- Skin disorders AZ: symptoms, cause and treatment
- Erythema annulare centrifugum (EAC): symptoms and causes
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