1 Poison ivy, poison oak, and poison sumac are plants than can cause an itchy rash upon contact. 2  A substance called urushiol, found in these plants, causes the rash. 3  The rash is not contagious.  The rash usually disappears in one to three weeks.
Common factors that can cause clogged ears are wax buildup, air flow blockage to the Eustachian tubes, pressure differences in the middle ear, and cold and sinus problems. Clogged ears can affect people of all ages, but is most common among children, especially when they have colds.
A sinus infection can cause clogged ears, ear pain and temporary hearing loss. A sinus infection is when your nasal cavities become swollen or inflamed, either due to an infection or as an allergic reaction. Ear pressure is a common symptom related to sinus infections.