Psychogenic cough is most commonly encountered in children and adolescents. A persistent cough due to an unidentifiable cause is the most important symptom. A detailed patient history and thorough physical examination are most important parts of the diagnostic workup, which must exclude organic causes prior to making the diagnosis.
Defining clinical details of psychogenic cough are yet to be solidified, but a sudden onset of a barking or honking cough that appears due to an unknown trigger and its absence during nighttime are proposed as clinical criteria [1]. It is described in individuals of all ages [2] [3] [4], but the pediatric population is most frequently diagnosed with this disorder [2], with some form of emotional stress or anxiety considered as the main cause. Other manifestations (for example fever or weakness) are never observed [5], but the cough may disrupt daily activities and can be severely debilitating for the patient, especially when the diagnosis is delayed because of other suspected etiology [3]. Most recent guidelines, however, dispute the abovementioned clinical manifestations as sufficient to make the diagnosis, as very little evidence exists to support such criteria [1]. In fact, the term psychogenic cough was proposed to be replaced with "somatic cough", given the fact that patients with a presumed diagnosis of a psychogenic cough fulfill the diagnostic criteria for a somatic symptom disorder, such as continuous presence of a symptom that consumes excessive time and energy and high levels of anxiety related to the present symptom [1] [6]. The diagnosis may be even further complicated when a concomitant presence or recent history of other respiratory disorders - asthma or respiratory tract infection, is noted [2] [3] [4].
An extensive workup is necessary for patients with a chronic and unexplained cough [7]. The first step is a detailed patient history that can reveal possible triggers (allergens, tobacco, occupational exposure to irritants, or drugs) and assess the onset and progression of the cough [2]. If additional manifestations (fever, productive cough, weakness, nasal discharge, pain, epistaxis, etc) are noted, an infection of the upper respiratory tract, either bacterial or viral, is much more likely. Nevertheless, a thorough physical examination, with an emphasis on the respiratory system (lung auscultation and a proper throat exam, including indirect laryngoscopy), should follow [2], and if the etiology is still not disclosed, several other diagnostic procedures can be performed. Functional lung testing through spirometry, imaging studies (computed tomography) and allergen testing are recommended, but crucial part of workup if psychogenic cough is suspected is an interview with a clinical psychologist [1], which can provide more information about the emotional background of a patient [2] [7]. It is not uncommon for patients to stop coughing after guided counseling sessions [2] [7], further emphasizing the role of a clinical psychologist in evaluating chronic unexplained cough.