[Annular erythema of infancy].

Many skin diseases appear as annular lesions. Some are more typical of adults or older children, whereas others usually appear in young children. Annular or figurate erythema of infancy comprises a group of dermatoses in which the primary lesion adopts an annular, oval circinate, or polycyclic pattern. Similarities in clinical presentation, age at onset, and duration of lesions mean that these conditions are difficult to diagnose; sometimes, they can only be identified by subtle differences in their clinicopathologic features. Clinical pictures enable us to distinguish one member of this group of diseases from another and also to differentiate them from other annular eruptions. For ease of description, we classify annular erythema of infancy into 2 types: conditions with a known etiology and conditions with characteristic reaction patterns but uncertain etiology.