A 5-month-old infant is brought to the clinic for an itchy rash that has waxed and waned for the past 6 weeks. The parents report frequent scratching and poor sleep. The infant has a history of wheezing episodes and the father has allergic rhinitis. Physical examination shows erythematous, scaly plaques with excoriations on the cheeks and the outer (extensor) surfaces of the elbows and knees. There is no honey-colored crusting.

Which of the following body surface distributions is most characteristic of this condition as patients get older?