Contemporary Pediatrics Puzzler

Infant girl develops bulging sacral massA 3-week-old female presented to the emergency department with a 3-day history of a progressively enlarging, erythematous, seemingly painful lump on her back.
Infant’s seizures and skull fracture could point to child abuseA 5-month-old Hispanic male presented to the emergency department (ED) at a children’s hospital in the Northeast United States directly from his daycare after caretakers witnessed 2 shaking, seizure-like episodes. The episodes lasted 1 to 2 minutes in the setting of a fever as palpated by the parents.
Pallor and swelling in an athlete’s upper armA 15-year-old female presents to the emergency department of a community hospital with acute onset of duskiness in her left arm.
Nervous teenager’s hands turn blueThe father of a healthy 15-year-old girl brings her to the emergency department (ED) for evaluation of blue hands.
Delayed menarche with normal pubertal growthA 14-year-old female presents for a wellness visit. On history, she is noted to not have started her menstrual cycle but on physical exam has significant breast and pubic hair development since the age of 10 years.
Boy with ear pain and facial weaknessA 13-year-old boy with poorly controlled type 1 diabetes (T1D) presents to the emergency department (ED) for evaluation of left ear pain and left facial weakness.
Erythema and ecchymosis after newborn’s phototherapyA male infant is born and delivery is remarkable for yellow amniotic fluid and a jaundiced infant. Following delivery he is given intensive phototherapy and then develops erythema, which later becomes ecchymosis. What's the diagnosis?
Right question resolves teen’s pain dilemmaA 16-year-old girl presents to an emergency department (ED) accompanied by her boyfriend to report a 24-hour history of right lower quadrant pain. The pain is associated with midline lower back pain and light vaginal bleeding (1 to 2 tampons per day). She has experienced some nausea but no vomiting.
Infant with failure to thrive and hypotoniaA 4-month-old girl arrives at the clinic for a well-child visit. Her mother voices concerns about the infant’s poor weight gain, slow feeding habits, and physical delays such as head lag, poor grasp reflex, and rolling over.
Tight, shiny membrane encases newborn’s skinAfter a cesarean delivery at 30 weeks, a 1430-gram premature female neonate was noted to have generalized thick, dark brown scale forming a tight membrane over her entire skin surface. Her mother was a healthy 19-year-old gravida 1 with normal prenatal screening ultrasound and laboratory studies. Family history did not reveal any congenital malformations or genetic disorders.