What are some of the complications of this disease, assume that the top of your differential is the definitive?

Keisha, a 13-year-old female, has come into your urgent care center. She has red conjunctiva, a cough and a fever of about 104 F, She also has a rash on her face a possibly the beginning of a rash on her arms. About 10 days ago she was around another student who had similar symptoms.
Write three (3) differential diagnoses?
What are some of the complications of this disease, assume that the top of your differential is the definitive?
Assume that the second item you place on your differential is the definitive diagnosis. What are some complications of that disease?