unilateral laterothoracic exanthem
An idiopathic* dermopathy affecting children ± age 2 (6 months to 10 years), male:female ratio—2:1, more in winter and spring, typically after a fever, upper respiratory or gastrointestinal prodrome, resolves spontaneously in 3 to 6 weeks.
Clinical findings Predominantly unilateral exanthem that spreads centrifugally. It typically arises in the axilla, less often in antecubital, inguinal or popliteal folds
*Viral aetiology is suspected
Synonym Asymmetrical periflexural exanthem of childhood
Reference Am Family Physician 2013; 87:791-792