Final answer:
The discussion describes skin conditions in newborns but the described well-circumscribed erythematous plaques on a newborn require medical evaluation to determine the specific cause and treatment.
Step-by-step explanation:
The question describes indurated well-circumscribed nodular erythematous plaques on the shoulder and back of a newborn, which could potentially be indicative of a number of skin conditions that might present in neonates. The discussion on skin conditions in newborns addresses various common findings such as vernix, lanugo, and developmental features like brown fat and the prominence of the head relative to the body. However, the presentation of well-defined erythematous plaques suggests a more specific skin condition that could require medical evaluation, and might relate to infections, congenital disorders, or inflammatory conditions. It's important for a clinician to evaluate these findings to determine the underlying cause and appropriate treatment.