An 11-year-old boy presented with recurrent, self-healing, asymptomatic eruptions involving trunk, over the last three years. The eruptions used to start as small red papules, progressing centrifugally to form annular plaques with a central clearing. No systemic features or mucosal lesions were present. Physical examination revealed multiple erythematous annular and polycyclic plaques, with trailing scaling at their inner margins (Fig. 1). The lesions were present exclusively on trunk; rest of the muco-cutaneous examination was non-contributory. There was no lymphadenopathy. KOH mount of scales did not reveal any fungal hyphae. Blood investigations were non-contributory. Histopathology from the erythematous margin showed mild hyperkeratosis, focal parakeratosis, and perivascular lymphocytic infiltrate in the superficial as well as deep dermis. The patient was diagnosed with erythema annulare centrifugum (EAC).

(a)                                                     (b)

Fig. 1 Annular erythematous plaques with trailing scales on trunk; on presentation (a), and after 2 weeks (b).

EAC is one of the figurate or gyrate erythemas, others being erythema marginatum (transiently seen in acute rheumatic fever), erythema migrans (rash of localized Lyme disease caused by Borrelia burgdorferi) and erythema gyratum repens (usually associated with visceral malignancy, pulmonary tuberculosis, lupus erythematosus and azathioprine). EAC presents as asymptomatic annular, arcuate, circinate, or polycyclic erythematous plaques with indurated margin and a trailing scale noted on the inner aspect of the advancing edge. Rapid progression is typically seen. The condition is recurrent and the course may last 4-6 weeks to many years. It has been documented in association with infections, drugs (Chloroquine, Hydroxychloroquine, Piroxicam, salicylates, Amitrip-tyline, Hydrochlorothiazide etc), pregnancy, and malignancy. The differential diagnoses include tinea corporis (itchy, papules/ pustules at the margin and fungal hyphae on KOH mount), subacute cutaneous lupus erythematosus, and other figurate erythemas. Topical steroids usually cause resolution of the lesions of EAC, but they do not prevent new lesions or recurrence. A search for, and treatment of the underlying disorder is warrented, but an exhaustive workup for occult malignancy for EAC alone is not recommended.