10-year-old boy seen in Urgent Care today for what we thought was a sinus infection. Blood pressure was taken and was low at 80/40. Diagnosed with allergic rhinitis and pharyngitis and cough, prescribed steroid tablets (which he has not started yet). Every morning (for past several months) he already takes 10 mg Zyrtec, Pulmicort 90 mcg, and Flonase 50 mcg nasal spray. 5 hours later he now has temp of 100.5 and bright red cheeks. What could this be.

Summarized question: What causes fever, red cheeks, rhinitis, pharyngitis and cough?