After teaching nursing students about childhood exanthems, the instructor determines that the teaching was successful when the students identify what as the primary cause?

The correct answer is - viruses.

Explanation:

Most of the exanthems that occur in childhood are due to viruses such as adenovirus, measles, chickenpox and many others including various herpes infections.

These exanthems are very normally common in general but appearance could be different. Viral exanthems are major cause of the childhood exanthems these are appeared to pink or red skin patch over various and large part of body.

Thus, the correct answer is - viruses.