Erythema marginatum

Erythema marginatum is described as the presence of pink rings on the trunk and inner surfaces of the limbs which come and go for as long as several months. It is found primarily on extensor surfaces.

An association with bradykinin has been proposed in the case of hereditary angioedema.

Presentation
The rings are barely raised and are non-pruritic. The face is generally spared.

Associated conditions
It occurs in less than 5% of patients with rheumatic fever, but is considered a major Jones criterion when it does occur. The four other major criteria include carditis, polyarthritis, Sydenham's Chorea, and subcutaneous nodules. In this case, it is often associated with Group A streptococcal infection, otherwise known as Streptococcus pyogenes infection, which can be detected with an ASO titer.

It is an early feature of rheumatic fever not pathognomic of it. It may be associated with mild myocarditis (inflammation of heart muscle). It is also seen in conditions like allergic drug reactions, sepsis and glomerulonephritis.

Types
Some sources distinguish between the following:
 * "Erythema marginatum rheumaticum"
 * "Erythema marginatum perstans"