Q. A 3-year-old girl is brought to the physician’s office by her mother for worsening dry and itchy skin on her extremities for the past 6 months. Her mother says that the itch is worst at night and disturbs the child’s sleep. She has been using emollients but they are giving temporary relief. The child is not allergic to any food. Family history shows that her older brother has cow milk allergy. Her temperature is 98.4°F (36.9°C), pulse is 100/min, blood pressure is 90/70 mmHg, and respirations are 15/min. Physical examination shows scattered areas of dry scaly erythematous papules with some excoriations on the flexural aspect of both extremities. Facial skin shows small round patches of hypopigmentation. The child has a runny nose and oral examination shows cobblestoning of the posterior pharynx. The rest of the examination is unremarkable. What is the most likely diagnosis based on her clinical findings?