A constant tickle in the throat can drive you crazy, especially when it causes you to cough at inopportune times. The sensation is caused by a mild inflammation in your throat -- enough to tickle, but not to hurt. A dry cough often accompanies the tickle because your body senses the inflammation and is trying to remove whatever might be irritating your throat. Unfortunately, though, unless you've got a foreign object in your throat, the cough is unlikely to do more than embarrass you. Getting rid of the problem means addressing the cause of the irritation.
After a Cold or Flu
A cold or flu causes many unpleasant symptoms, and it can leave behind the sort of mild throat irritation that will cause an aggravating tickle in your throat until the irritated tissues settle down. If the constant tickling sensation started after a cold or flu, the only way to get rid of it is to wait it out. It should go away within about three weeks. In the meantime, you can use throat lozenges or even hard candy to ease the tickle temporarily, especially for those times you don't want to burst out coughing.
Due to Allergies
If you have nasal allergies, the frequent postnasal drip that comes with allergies can be enough to irritate your throat and cause that constant tickle. If you suspect this is the cause, try allergy medicines -- with your doctor's OK -- to dry up your nasal secretions. Antihistamines or steroid nose drops can often be helpful. If you need advice on drying up your postnasal drip, ask your doctor.
Acid reflux is another common cause of mild throat irritation -- including a constant tickle -- and a dry cough. Stomach acid irritates the throat and can cause a minor chronic irritation that leads to the tickling sensation. If you suspect you have acid reflux -- especially if you have other symptoms, such as frequent heartburn or nausea -- see your doctor. Lifestyle changes, such as losing weight or sleeping with your head elevated, often can ease the problem. Your doctor might also prescribe medicines.
A constant throat tickle, especially with a dry, unproductive cough that continues to irritate the tissues of the throat, can have other causes as well, although these are less likely. Some people have asthma but their only symptom is a dry cough, though this is rare. Another extremely rare cause is lung cancer. Although no one should jump to frightening conclusions, it's worth seeing your doctor for a diagnosis of the cause of your irritated throat and dry cough, especially if none of the common causes seem to be your problem -- and if you're a smoker or the unexplained cough persists more than a month.