Got an email from the doctor at the university today and it appears Daniel just had a reaction to a random virus. The doctor wrote,
In summary, it seems like Daniel had an acute viral infection that gave him the fever, joint pain, and the rash. We call those infections ‘viral exanthems’. Although parvo is one of the common causes of viral exanthems, there are many other viruses that are known to cause this, and probably many many more that are not even known to us. As we told you, as long as he feels better and the symptoms disappear, it doesn’t really matter the exact name of the virus that caused it.
And that's okay with me. Thank you, Lord.