The type of cough associated with a tickle in the throat is a dry cough, which is typically caused by inflammation in the throat, according to NHS Choices. The cough occurs because the brain interprets the presence of the inflammation as an actual irritant and provokes coughing to try to remove it.
A dry cough is also known as a non-productive cough because it fails to bring up any mucus. As noted on A. Vogel, "tickly" coughs are often caused by colds or the flu, and can also be triggered by an allergic response to hay fever, pollution, smoke and very cold air. When the cause is pollution or smoke, the cough is caused by tiny particles being trapped in the throat's mucus lining and irritating it.
Sometimes non-productive coughs become chronic, and according to the Mayo Clinic, this can indicate the presence of an underlying disease or other cause. Causes for chronic, non-productive coughs include asthma, gastroesophageal reflux disease, whooping cough, lung disorders and reactions to ACE inhibitors. A major cause of this type of cough is postnasal drip, which causes the nasal passages to become inflamed, often due to allergies, and mucus to enter the back of the throat.