Erythema marginatum is a type of erythema which involves ring-shaped, circular red regions on the torso and extremities. The rash is non-itchy and non-painful, leaving the area of the face uninvolved.
Erythema marginatum is a type of rash, commonly associated with rheumatic fever. Its typical appearance involves disc-shaped skin lesions that assume the color of pink to red on their margins, while the central region is pale-colored. The edges are usually elevated, but the center remains flat and small. The progressive formation of the lesions accounts for their uneven edges and their diameter ranges from small (0.5 centimeters) to large (up to 8 centimeters).
The torso and inner sides of the extremities are the location on which erythema marginatum usually appears. The external parts of the limbs and face are usually lesion-free; the lesions typically increase in size during the course of the disease and tend to spread, covering a more extensive region, compared to their initial arrangement.
This type of erythema does not cause any additional symptoms, such as itching, pain or a feeling of heat and burning; this is often the reason why it is not a concern to the patients. However, increased levels of heat tend to exacerbate its appearance: the lesions darken in color and are restored to their initial appearance as soon as the temperature is restored.
Erythema marginatum is diagnosed by observation, based on the existence of its typical characteristics. Lesions that are macular, with elevated borders and a flat edge and pink- or red-colored indicate a possible case of erythema marginatum. The absence of any feelings of discomfort also corroborates the existence of this specific condition.
Further tests aim at diagnosing a potential underlying rheumatic fever. Echocardiography should be performed on the heart, in order to detect possible cardiac involvement . The complete physical examination should also involve an examination of the joints and related medical history, heart auscultation, blood tests in order to check for inflammation markers and, as a last resort, a skin biopsy, reserved for cases that cannot be confirmed otherwise .
Therapeutic plans used to treat erythema marginatum depend on the causes of the rash. If the patient is diagnosed with rheumatic fever, proper treatment should be administered for the autoimmune disease. Its resolution will lead to the resolution of erythema marginatum as well, since the latter is a symptom caused by rheumatic fever.
More specifically, rheumatic fever is treated with regular injections of penicillin, salicylates (i.e aspirin) and anti-inflammatory medications including corticosteroids. Further medications are necessary to treat cardiac inflammation: digoxin, diuretics and ACE inhibitors are usually prescribed, depending on the extent of the inflammatory cardiac response. Although erythema marginatum is expected to fully subside as soon as the patient is successfully treated for rheumatic fever and the other symptoms have been relieved, in some cases it may fail to disappear. This condition indicates the need for further consultation and the consideration of an alternative cause which has escaped detection.
If erythema marginatum has developed due to hereditary angioedema, a different course of treatment is necessary. The primary target is to increase the levels of C1-inhibitor (C1-INH), an acute phase protein that prevents the spontaneous activation of the complement system. C1-IHN concentrations can be augmented via transfusions from a donor in cases of a severe, acute attack, or via the administration of danazol. Danazol is an androgen which is known to lead to increased levels of C1-inhibitor, even though the exact physiological pathway that underlies the process remains unknown. Tranexamic acid has been suggested as a possible treatment option, but its efficacy has been doubted up until now.
Rheumatic fever and its symptoms, such as erythema marginatum, are expected to subside within twelve weeks, if no treatment is administered. If the patient receives the proper treatment, however, symptoms are expected to disappear in the first two weeks following its initiation. Symptomatology affecting the heart tends to persist for up to two months and a reappearance of arthralgia and fever may be anticipated, should the discontinuation of anti-inflammatory and steroid medication be conducted too abruptly. This does not constitute a disease recurrence. Anti-inflammatory medication can be administered to the patient again with gradual tapering prior to discontinuation.
Erythema marginatum, alongside the other symptoms caused by rheumatic fever, completely resolve when the patient has been effectively treated for the disease. Nevertheless, patients remain susceptible to a relapsing disease pattern and are at a considerable risk of being affected by rheumatic heart disease. The latter is believed to occur more frequently to patients who have experienced a severe case of acute rheumatic fever or frequent relapses . The absence of carditis during the initial episode does not eliminate the possibility of such a complication during a relapse phase .
For these reasons, prophylactic antibiotic coverage is considered to be of paramount importance, since it reduces the possibility of recurrence   .
Erythema marginatum involves a rash caused by the neutrophilic and lymphocytic infiltration of the vessels in the lower layers of the skin. The condition may arise spontaneously and without a known cause, or, more commonly, it may be associated with rheumatic fever.
Rheumatic fever is an inflammatory disease caused by a group A streptococcal bacterial infection and is usually initiated following a streptococcal pharyngeal infection. In order to diagnose rheumatic fever, two of the following 5 major criteria have to be present:
Erythema marginatum is known to be activated by elevated temperature; it has been proposed that this is the reason why it does not develop until up to 3 weeks after the patient becomes febrile.
In countries of the industrialized West, rheumatic fever is not diagnosed in daily clinical practice and is considered a rare condition since 1980, despite a slight increase in the diagnosed cases in the USA during the 90s . However, underdeveloped countries still report an elevated incidence of rheumatic fever.
Erythema marginatum is one of the five major criteria utilised to diagnose rheumatic fever. It occurs early in the course of the disease, alongside carditis, and earlier than polyarthritis. Rheumatic fever has been established as an autoimmune condition, that arises as a response to a bacterial infection caused by group A Streptococcus that usually develops on the pharynx.
Although the exact pathophysiological mechanism that underlies the development of erythema marginatum remains unclarified, it has been suggested that cross-reactivity between human tissue and the antigens of group A Streptococcus is the possible trigger factor. The very same antibodies that are formed against the bacterial antigens are believed to cross-react with various other targets, including laminin, cardiac myosin, keratin and vimentin, thus leading to an extensive reaction that affects not only the skin, but the cardiac tissue, neuronal tissue and subcutaneous tissue as well . The heart is particularly affected by the autoimmune response, in terms of pericardiac, myocardiac and endocardiac inflammation; the myocardium often displays a granulomatous appearance when examined histopathologically, caused by the existence of Aschoff bodies . This inflammatory response can give rise to conduction abnormalities.
Erythema marginatum associated with rheumatic fever can be prevented, if rheumatic fever is prevented. In order for this to be achieved, streptococcal pharyngeal infections need to be diagnosed successfully and treated with penicillin, either per os or intramuscularly. An infection of the respiratory tract that is diagnosed as streptococcal or is believed to be streptococcal in a patient with a prior history of rheumatic fever or risk factors for the condition should never be left untreated.
Erythema marginatum (EM) is a condition which leads to the appearance of an annular rash on the area of the torso and proximal extremities. This disc-shaped type of erythema has got two distinct characteristics: slightly raised edges and a flat central point. The erythematous regions are almost always confined to the aforementioned areas of the body, leaving the face unaffected; absence of pain or itchiness is a characteristic of the disease.
There are two types of EM:
Erythema marginatum is a type of erythematous skin rash. It appears on the torso and on the inner sides of the arms and legs, and its color ranges from pink to red. Erythema marginatum lesions have some typical characteristics: circular shape, elevated edges that are not evenly shaped and a central point that is flat and clear. The rash does not itch, it is not painful and does not cause a burning sensation to the region where it develops. The outer parts of the extremities and the face are typically free of the lesions.
Erythema marginatum may develop due to causes that are unknown (idiopathic) or it may be a symptom of another condition, called rheumatic fever. Rheumatic fever is a complication of an infection with a particular bacterium, group A streptococcus. The infection affects the respiratory tract and primarily the pharynx. Antibodies produced against the bacterial parts also attack organs of the patient's body as well, through a process known as cross-reactivity. This means that rheumatic fever is an autoimmune disease, triggered by a streptococcal infection. Except for the skin, on which erythema marginatum develops, rheumatic fever also involves inflammation of the heart and joints, as well as neurological complications. Erythema marginatum is one of the five major criteria (Jones criteria), which are utilized to diagnose rheumatic fever.
The rash typically appears early during the course of rheumatic fever, before arthritis, and approximately at the same time as the inflammation of the heart, if present. The skin lesions are sized between 0.5 to 8 cm in diameter and may become worse if the patient finds themselves in conditions where the temperature is elevated, such as in a hot shower. It is also usually the last symptom to resolve after therapy has been administered.
Erythema marginatum is diagnosed by observation of its characteristics. The primary target of diagnosis, however, is the detection of rheumatic fever. The condition is diagnosed with various examinations, including echocardiography, examination of the joints and blood tests which will reveal various inflammation markers. Treatment also focuses on rheumatic fever: injections of penicillin, salicylates, anti-inflammatory medications and drugs used to treat heart conditions may all be required to treat rheumatic fever and, subsequently, erythema marginatum. If the rash is caused by hereditary angioedema, transfusions of a specific protein (C1-inhibitor) or the administration of danazol are required to treat the condition and, as a result, the rash as well.