A habit cough or tic cough is a chronic cough that has no underlying organic cause or medical diagnosis, and does not respond to conventional medical treatment. This was also called a psychogenic cough but this has since been differentiated from a tic cough as somatic cough syndrome. Different terms and conditions involving this form of chronic cough were ill-defined and not well distinguished, and in 2015, guidelines for the different terminologies were issued, distinguishing tic cough, and somatic cough disorder. Coughing can be a tic. It may develop in children or adolescents after a cold or other airway irritant. Similar symptoms have been less frequently reported in adults but may not be the same disorder as is seen in children or adolescents.
Classification and name
History
In the 19th century, habit cough was also referred to as stomach cough. In the 20th century, the terms habit cough, tic cough, psychogenic cough, somatic cough syndrome and somatic cough disorder have been used to describe a chronic cough in the absence of an identifiable medical disease that does not respond to conventional treatment, and is considered to have a psychological or psychiatric basis. In 2015, the American College of Chest Physicians updated the 2006 guidelines to help define the differentiation in "suspected psychogenic, habit, or tic cough". They recommended, based on "low quality" evidence, that psychogenic cough be replaced with somatic cough syndrome, and habit cough be replaced with tic cough. The 2016 Korean cough guidelines refer to habit and psychogenic cough as the same thing. According to Anne E. Vertigan, it did not appear that the ACCP recommendations were used, and "it is unclear whether this is due to the timing of submission and publication or that the authors held a different professional perspective regarding the condition."
The ACCP in 2015 recommended that the name somatic cough syndrome replace psychogenic cough to provide more consistency with the 2013 Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. They recommended eliminating the term psychogenic "because functional imaging studies have started showing cerebral correlates for disorders previously thought to be of a pure psychogenic nature". Vertigan wrote in 2017 that the distinction between other types of chronic cough and somatic cough syndrome is not entirely clear.
Habit or tic cough
The ACCP recommended in 2015 that the name tic cough replace habit cough, to reflect shared characteristics with tics and tic disorders and to be consistent with DSM-5 terminology on motor disorders. Weinberger and Lockshin wrote in 2017: "However, our experience has found habit cough to fit the syndrome best, and has been most acceptable to the families in diagnosing and explaining the nature of the disorder."
Symptoms
Habit cough is characterized by a harsh barking cough, and becomes persistent for weeks to months. The cough's hallmarks are severe frequency, often a cough every 2–3 seconds, and the lack of other symptoms such as fever. The child can have trouble falling asleep but once asleep will not cough. Absence once asleep is considered essential.
Diagnosis
There are many causes of chronic cough, and there is little consistency or consensus about how best to diagnose the condition.
Treatment
Treatments has involved hypnosis and suggestion therapy. Suggestion therapy was first described in 1966 in a small case series; further publications identified patients with the same symptoms treated effectively with suggestion therapy.
