1. This is an 18-month-old boy who was healthy until about 8 days ago when his mother noted reddened blotches on his neck and trunk particularly his upper back.

The reddened blotches on the 18-month-old boy's neck and trunk, particularly his upper back, could be indicative of a medical condition or skin issue. To determine the cause, it's important to consult a healthcare professional, such as a pediatrician or dermatologist. They will be able to conduct a physical examination and take into consideration the boy's medical history to provide an accurate diagnosis.

When seeking medical help for such symptoms, it's helpful to note down any additional relevant information, such as the duration of the rash, any associated symptoms like itching or pain, recent changes in the child's routine, exposure to potential allergens or irritants, and any recent illnesses or infections. This information can assist the healthcare provider in identifying the cause of the rash and determining the best course of action for treatment.

Thus, the first step in understanding the cause of the reddened blotches on the boy's body is to consult with a healthcare professional who can evaluate the child's condition and provide an accurate diagnosis.