Objectives: To review the literature on habit, tic, and psychogenic cough, and to make evidence-based recommendations regarding diagnosis and treatment.
Design/methodology: For data on adults, an Ovid MEDLINE literature review (through February 2005) was performed for all studies published in the English language, including case series and case reports, since 1966 using the medical subject heading terms "habit cough," "psychogenic cough," "tic disorder," "vocal tic," "Tourette's syndrome," "honking cough," and "barking cough." For pediatric data, articles were identified dating from 1966 from searches of the Cochrane Library, PubMed, EMBASE, the list of references in relevant publications, and the authors' collection of references with the last search performed in February 2005. The search terms used were "children" and "vocal tics" or "habit cough," or "psychogenic cough" or "chronic cough."
Results/conclusions: The methodologies used and rigor of the diagnostic and therapeutic interventions reported in the literature are inconsistent. The putative clinical characteristics of habit cough and psychogenic cough, for the most part, have not been prospectively or systematically studied. Therefore, on the basis of expert opinion, the diagnoses of habit cough or psychogenic cough can be made only after an extensive evaluation is performed that includes ruling out tic disorders and uncommon causes of chronic cough, and when cough improves with behavior modification or psychiatric therapy. In adult patients with chronic cough that remains persistently troublesome despite an extensive and thorough evidence-based evaluation, and after behavior modification and/or psychiatric therapy have failed, unexplained cough should be diagnosed rather than habit cough or psychogenic cough. In children, the depth of investigations to rule out uncommon causes must be individualized as some investigations and/or treatment may increase morbidity. In adult and pediatric patients with chronic cough that is associated with troublesome psychological manifestations, psychological counseling or psychiatric intervention should be encouraged after other causes have been ruled out.