Erythema Marginatum

Erythema marginatum is a non-painful dermatological disorder that affects many adults and children across the globe and often goes unnoticed. Read and know all about the symptoms, causes, diagnosis and treatment of this ailment.

Erythema marginatum Definition

It is a rare condition of the skin marked by the presence of multiple pink circles or rings on the trunk and inner regions of the arms and limbs. These rings are generally found on surfaces that underlie the extensor muscles which extend or straighten a limb or any other body part. The condition is usually associated with periodic appearance and disappearance of these skin rashes that may even continue for months.

Erythema marginatum Types

The disorder is classified into two different forms:

Picture of Erythema marginatum

Picture 1 – Erythema marginatum

Erythema marginatum rheumaticum

This particular form is asymptomatic and occurs superficially. It is generally considered to be a type of gyrate erythema – a non-specific group of cutaneous disorders – the causes of which are unknown. It is typically associated with rheumatic fever due to which multiple eruptions get scattered over the trunk and upper areas of the arms or legs.

Erythema marginatum perstans

In this case, erythematous lesions generally spread all over the skin of the thighs or legs. These can also be present on other regions of the body, except on the palms or soles. The lesions grow at a higher rate and could either be superficial or deep in type. This condition is also a part of gyrate erythema and may have an underlying disorder.

Erythema marginatum Incidence

The disorder commonly affects the light-skinned population. It accounts for 2-5% of cases of rheumatic fever and affects males twice as often as females.

Erythema marginatum Symptoms

The rashes are normally doughnut-shaped. In some patients, the condition may appear as serpiginous where these skin lesions have a wavy or indented margin similar to the shape of a snake. Such a pattern of growth can be highly attributed to the slow development of the condition. The rings are not elevated and could be open or closed. Although the disorder affects multiple areas on the body, such light pink circular rings are not observed on the face of an affected patient.

The condition is represented by macular rings with pale centers, which are small, flat, distinct circumscribed changes in the color of the skin. These macules are neither elevated nor depressed, but have sharp and well-demarcated edges. Adjacent rings, that give rise to polycyclic configuration, comprise of a class of cyclic configurations. The skin condition spreads peripherally while clearing centrally.

The circular areas are normally non-pruritic due to which the skin does not undergo irritation or itchy sensations. The macules may become worse with increase in the body temperature or while taking a hot shower, but reduces when a patient attains normal temperature.

The diameter of the annular lesions may vary from few to several centimeters. The rashes usually begin on the lower trunk and migrate slowly in the upward direction. The lower rashes disappear when the upper ones become visible. In some patients, residual hyperpigmentation may also occur and can be characterized by the development of rashes that are either dull red or brown or violet.

Erythema marginatum Causes

The superficial as well as the deep dermal vessels undergo acute lymphohistiocytic thickening. Here, basically the lymphocytes and the phagocytic cells called histiocytes are responsible for triggering inflammation of the blood vessels. This causes a sudden transformation of the epidermal layer of the skin.

The exact etiology of this disorder is still undetermined and could even arise spontaneously. However, there are certain factors that may possibly produce such polycyclic skin rashes. Some of them include:

Rheumatic fever

It is an inflammatory disorder caused by a bacterium called Streptococcus pyogenes. The disorder can adversely affect the heart, joints, brain and skin. Presence of ring-shaped eruptions on the skin is a common symptom of this condition. High fever intensifies the rashes and turns them more severe. The macules take on a snake-like appearance when a number of such rings aggregate.

Hypersensitivity

Excess intolerance or reactivity towards a wide spectrum of stimuli or agents may generate an allergic skin reaction in the form of such rashes. Food allergy frequently causes this condition. Blue cheese and tomatoes are the most common food allergens.

Malignancy

The condition can also be present as a serious symptom in many life-threatening disorders like lymphoma, leukemia, squamous cell carcinoma, and breast cancer.

Infection

Small reddish eruptions can sometimes be an outcome of an array of infections caused by Escherichia coli, Candida albicans or Ascaris lumbricoides

Drugs or chemicals

In some cases, regular intake of antimalarial chloroquine/hydroxychloroquine, gold, penicillin and cimetidine could be linked to this condition.

Erythema marginatum Diagnosis

The diagnosis of the disorder is completely based on the observation and examination of the skin of affected patients. A thorough analysis of a patient’s medical history is equally important to the physicians to verify presence of any other associated disorder or use of any drug. A skin biopsy is often essential to rule out the possibility of other associated cutaneous disorders. A small section of the outermost layer of macular skin is removed for further examination. In case of any infection, swabs cultures can be taken to detect the presence of the causative microorganism.

Rheumatic fever can be exclusively diagnosed by using the following tests:

  • Blood test to evaluate the complete blood count
  • Throat swab to detect the presence of Streptococcus pyogenes
  • Electrocardiogram (ECG) to check the functioning of the valves and chambers of the heart

Erythema marginatum Differential Diagnosis

The symptoms of the condition are similar to Hives or Urticaria – a condition marked by red, itchy, raised areas of skin in various shapes and sizes. Drug reaction can flare up such eruptions on the skin. Unlike Urticaria, however, these rashes are neither pruritic nor elevated. These few points may aid the health care providers as the basis for distinguishing the condition from ordinary hives.

Erythema marginatum Treatment

Management of the condition requires treatment of any underlying disorder as well as withdrawal of any drugs that might be aggravating it. Foods that evoke allergic reaction should be completely avoided.

Rheumatic fever, being the most common cause of this condition, must be treated by appropriate means. Eradication of the bacteria can be accomplished by using penicillin or benzathine benzylpenicillin. This prevents the throat from another bacterial attack. Patients with significant inflammatory response may require corticosteroids. Use of salicylates may ease pain and reduce fever.

Erythema marginatum Complications

This dermatologic condition does not usually involve any severe consequences. However, problems like Rheumatic fever may give rise to a few complications like:

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Picture 2 – Erythema marginatum Image

  • Myocarditis
  • Subcutaneous nodules
  • Sydenham’s Chorea
  • Polyarthritis

Erythema marginatum can be prevented by timely recognition and diagnosis of the bacterial infection that causes rheumatic fever. The condition is not fatal or contagious and can easily recover on its own. Long-term antibiotic treatment can prevent the reoccurrence of fever. Medical experts are continuously attempting to develop a vaccine in order to completely eliminate rheumatic fever, which in turn could prevent formation of such lesions.