Dermatology Made Easy is based on the most popular topics from DermNet NZ's vast array of material. The book combines the essential focus of the ‘Made Easy’ book series with the authority and knowledge base of DermNet NZ's unparalleled resources.
Author: Vanessa Ngan, Staff Writer, 2003. Updated by A/Prof Amanda Oakley, July 2015.
Erythema annulare centrifugum refers to a number of chronic annular (ring-shaped) and erythematous (red) skin eruptions. Other descriptive terms have been used to classify these types of lesions, including:
Erythema annulare centrifugum may occur at any time throughout life, from infancy to old age. The eruption usually begins as small raised pink-red spot that slowly enlarges and forms a ring shape while the central area flattens and clears. There may be an inner rim of scale. The rings enlarge at a rate of about 2–5 mm/day until they reach a diameter of about 6–8 cm. Sometimes the lesions do not form complete rings but grow into irregular shapes. One or several lesions may be present.
Erythema annulare centrifugum most often appears on the thighs and legs, but may occur on the face, trunk and arms. The lesions rarely cause symptoms but in some patients may cause mild itching or stinging.
Often no specific cause for erythema annulare centrifugum is found. However, it has been noted that erythema annulare centrifugum is sometimes linked to underlying diseases and conditions. These include:
In these situations, erythema annulare centrifugum resolves once the underlying cause is treated or the offending drug is stopped.
The diagnosis of erythema annulare centrifugum is made clinically, and confirmed by histopathology showing perivascular lymphocytic infiltration.
Further investigations may be carried out to exclude other causes of annular rashes and to look for an underlying cause, if any.
Differential diagnosis includes:
Erythema annulare centrifugum usually clears up by itself. Eruptions may be last from anywhere between a few weeks to many years (the average duration is 11 months). Most cases require no treatment (and no curative therapy is known). However, topical corticosteroids may be helpful in reducing redness, swelling and itchiness.
Book: Textbook of Dermatology. Ed Rook A, Wilkinson DS, Ebling FJB, Champion RH, Burton JL. Fourth edition. Blackwell Scientific Publications.
See the DermNet NZ bookstore
© 2018 DermNet New Zealand Trust.
DermNet NZ does not provide an online consultation service. If you have any concerns with your skin or its treatment, see a dermatologist for advice.