Hello, Amoclan may cause an allergic reaction and swelling of the respiratory tract. This is not supposed to happen for moment only. An allergic reaction will cause swelling that will persist until the reaction is over, usually several hours to days after the last dose was taken. Pharyngitis may also cause swelling of various structures of the upper respiratory tract. Sometimes the nostrils may be occluded because of coexistence nasal congestion. Clinical examination by your doctor is the best way to distinguish between different possibilities. If you re having shortness of breath then immediate action would be required. I hope you find my comments helpful! You can contact me again if you d like any clarification or further information. Kind regards!