Coughing can present itself in various disguises. Doctors often look at coughing through the eyes of their own specialty. To an allergist, it’s a tickle in the back of the throat and a symptom of post nasal drip. To a gastroenterologist, coughing is due to reflux disease; to a psychiatrist it’s a nervous reaction. The infectious disease specialist wants to know if the cough could be due to HIV.