Is there a shot the doctor can give to help reduce the symptoms of croup?

Yes, but.........: Croup is an infectious (usually viral) narrowing of the upper airway due to inflammation. Steroids (usually dexamethasone) are potent anti-inflammatory medications to help reverse this process. Often given im, the same result can be obtained if taken orally.

Croup: The respiratory distress associated with viral croup can sometimes be treated with steroids, given by intramuscular injection (shot), orally, or intravenously. Other treatments such as cool mist to the face or nebulized Epinephrine (racemes epinephrine) are sometimes used. Not all patients with croup require medication.