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.
Plugged Ears Caused by Fluid in the Ear. Plugged ears can be a result of trapped fluid in the auditory tube. The auditory tube normally carries unwanted debris from the ears to the back to the throat where it is swallowed but sometimes it can become plugged and fluid becomes trapped in the middle ear.