What is Erythema Marginatum?
These are pink rashes that form on the trunk and on the surface of the inner limbs. They may come and go or stay for as long as several months. These are rashes primarily found on the extensor (muscle that extends or straightens a limb or body part) surfaces..
Erythema Marginatum Rash
Erythema marginatum has the following characteristics which differentiate it from other exanthems that may be caused by viral infections or other diseases.
- Pink circular-ring like rash that appears on the trunk, distal parts of the extremities or surface of the inner limbs
- Rings are slightly raised
- Non-pruritic (not itchy)
- Rashes usually spare the face
- Rashes blanch under pressure (they become lighter in color when pressed)
- Not painful
- Persists for a few minutes or hours but can last weeks or months
- May recur
- Has a “smoke ring-like” appearance
- Primarily located on the extensor surfaces
Erythema Marginatum Causes
The specific cause of erythema marginatum is usually traced to an associated disease; this condition is not a separate disease entity and is usually belongs to an umbrella of symptoms related to another condition.
- Problems with the immune system including rheumatic fever and hereditary angioedema.
- Rheumatic Fever – Rheumatic fever is caused by a type of immune reaction called molecular mimicry, where the body’s antibodies attach to the bacteria and to the cells of the body itself. When immune fighters are released, they attack both the bacteria and the body cells. This then causes inflammatory reactions (includes rash formation in the skin).
- Hereditary angioedema – Hereditary angioedema is caused by a C1 esterase inhibitor deficiency. This deficiency leads to immune problems which may cause erythema marginatum.
- Bradykinin – Unusually high amount or deposits of bradykinin is also related to hereditary angioedema.
- The deposits of bradykinin can trigger a myriad of inflammatory reactions that can lead to rash formation. Bradykinin causes vasodilation or widening of the blood vessels. Wide blood vessels means more blood supply, and this increase in vascularity leads to erythema (redness) seen in erythema marginatum.
Erythema Marginatum Treatment
Treatment focuses on the diagnosed condition of the patient. If the individual is diagnosed with rheumatic fever, then treatment concentrates on treating rheumatic fever. If the manifestation of the erythema marginatum is due to hereditary angioedema, then the treatment revolves around the said condition.
- For Erythema Marginatum associated with Rheumatic fever – The following treatments are done to treat rheumatic fever and also lessen or relieve erythema marginatum:
- Regular Penicillin injections
- Salicylates such as aspirin
- Anti-inflammatory drugs such as corticosteroids
- ACE inhibitors, digoxin, diuretics and beta blockers if carditis is present
It should be noted that even if the stated treatments are employed, some cases of erythema marginatum could still persist. The same persistence can happen even if the other symptoms of rheumatic fever already subsided. In these cases, consultation with a physician for further evaluation and differential diagnosis is essential. For Erythema Marginatum associated with Hereditary Angioedema – The following treatments are done:
- Transfusion of C1-INH from a blood donor (an acute treatment especially if there is laryngeal swelling or edema)
- Prophylactic treatment of Danazol (an androgen) to increase the production of C1-INH. The mechanism behind the treatment with male androgens remains unknown, but it has the effect of increasing C1-INH, a component lacking in hereditary angioedema.
- Tranexamic acid can also be used though some studies suggest it has weak and questionable effects.
Erythema Marginatum Pictures
Erythema Marginatum found in inner aspect of limbs
Proofread on 20/12/2012