PEDIATRICS Vol. 106 No. 4 October 2000, pp. 852-853

EXPERIENCE AND REASON:
Use of a Peak Flow Meter for Positive Feedback in Psychogenic Cough

Peak flow meters are recommended for the control of chronic asthma.¹ They often detect airflow obstruction before it is clinically manifested, and can be a useful tool for asthma self-management. Early detection of airflow obstruction may result in earlier, more effective therapy.² In certain select cases the peak flow meter can be used to reassure a patient that symptoms are not being caused by asthma. We report such a case.

	CASE PRESENTATION

A.C. was first referred to us at age 8 1/12 years because of prolonged cough with upper respiratory tract infection (URI). By history she had cough only with URI, but the cough lasted 3 or more weeks with each URI. She had missed 15 days of school in each of the past 2 school years because of the cough. She had exercise induced cough only when otherwise ill. Nebulized albuterol provided some relief. She had occasional urticaria of unknown cause. Allergens do not provoke asthma symptoms, and there was no seasonal pattern to the asthma, other than the expected increased frequency of URI in the winter.

When initially seen she had developed a URI 1 week before, and was coughing considerably. Wheezes were heard on physical examination, which was otherwise unremarkable. She was controlled on beclomethasone, albuterol and a short course of prednisolone. She was subsequently seen when clinically well, and had a normal physical examination. However, spirometry revealed airflow obstruction, with her forced expiratory flow after 25% to 75% of vital capacity had been expelled (FEF_25-75) at 48% of the predicted value. Her clinical state and airway physiology were normalized with chronic beclomethasone, salmeterol and nedocromil, and prn albuterol. She did well for the next 6 months, with only minor cough with URI. She was no longer missing school.

At 8 9/12 years she developed a URI with cough controlled by her chronic therapy, prn albuterol and prednisolone was added at 2 mg/kg/day. On the fourth day of prednisolone, a cough returned. She was afebrile and had no headache, nasal discharge, eye, or nose symptoms. An unusual facial twitch was noted. The cough was harsh and barking, incessant throughout the day. The cough disappeared once she went to sleep. She was otherwise well. With the new cough she missed 2 days of school. There was no relief from changing the beclomethasone to fluticasone 220 µg BID, and adding ipratropium 2 puffs TID. A physician added hydrocodone and an antihistamine, but the cough persisted. The added therapy increased her sleepiness, indirectly decreasing her cough.

I saw her during Friday afternoon office hours, the seventh day of prednisolone. She had no cough in the office. Her physical examination and spirometry were normal, unchanged from her best baseline values. I stopped the hydrocodone and antihistamine, continued the other therapy. That weekend she remained cough-free, and the ipratropium was discontinued. On Monday in school she began coughing again, with the same pattern. Her mother was called to school. Mrs. C. brought the peak flow meter to school, showed A.C. that the peak flow was the same as it had been, and at the level of her personal best. The cough stopped and did not return. She was weaned off the systemic corticosteroids, and was again well-controlled on her inhaled therapy.

	DISCUSSION

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This young girl with moderate persistent asthma well-controlled on chronic inhaled therapy developed an exacerbation of her asthma triggered by URI. She had a good initial response to increased inhaled albuterol and oral corticosteroids, but after 4 days developed an unusual cough with a facial tic. There was no clinical evidence of sinusitis or allergies, and this occurred after the ragweed season. There was no direct response to cough suppressants or antihistamines. These did make her sleepy, which secondarily decreased her cough. A number of factors led me to believe the cough was psychogenic. The cough had a barking, "Canada goose" quality.^3,4 It disappeared as soon as she went to sleep. The facial tic was suggestive of anxiety, as well. The disappearance of the cough and the tic with the office visit was either attributable to reassurance,⁵ the sedating effect of some of her medications, or the upcoming weekend. The scenario the next Monday, after remaining cough-free over the weekend, confirmed the nature of the new cough. The inciting stress was never detected, and there has been no recurrence in the year since. She remains well-controlled with normal exercise tolerance. She does well in school, and takes part in soccer and basketball.

We prefer the terms "stress-related cough" or "anxiety-related cough" to the term "psychogenic cough." We find parents and patients more accepting of the former terms. This also emphasizes that the symptoms are a reaction to an external stress, not "in the child's head." A number of treatments have been suggested for this entity. Cohlan and Stone⁶ suggested wrapping the chest in a bed sheet, and we have used his technique with some success. Other treatments include relaxation techniques, biofeedback, and speech therapy.^5,7 We describe a child in whom the peak flow meter was used as positive biofeedback, with a resulting cessation of the previously troublesome cough.

In summary, we recognize that a child with asthma can have abnormal airway physiology in the face of a normal peak flow rate.⁸ Clinicians cannot assume that a normal peak flow rate signifies normal airway function. However, in select cases where the child has normal airway physiology, and the clinician has made a diagnosis of stress-related cough, the peak flow meter can be helpful in providing positive feedback to the child. We were able to use it successfully in our patient to abort the cough.

Michael R. Bye, MD
Pediatric Pulmonary Medicine
Babies and Children's Hospital of New York Presbyterian Hospital
Children's Lung Center
New York, NY 10032

	FOOTNOTES

Dr. Bye is a member of the speakers bureaus of Schering-Key, which makes an albuterol and beclomethasone inhaler; and Glaxo, which makes fluticasone.

Received for publication Dec 20, 1999; accepted Apr 4, 2000.

Address correspondence to Michael R. Bye, MD, Pediatric Pulmonary Medicine, Babies and Children's Hospital of New York Presbyterian Hospital, Children's Lung Center, 3959 Broadway, BH7S, New York, NY 10032. E-mail: mb255{at}columbia.edu

	ABBREVIATIONS

URI, upper respiratory (tract) infection.

	REFERENCES

Top Introduction Discussion References

1. Expert Panel Report 2: Guidelines for the Diagnosis and Management of Asthma. Bethesda, MD: National Asthma Education Panel and Prevention Program. National Heart, Lung, and Blood Institute; 1997. NIH Publication No. 97-4051
2. Lloyd BW, Ali MH How useful do parents find home peak flow monitoring for children with asthma? Br Med J 1992; 305:1128-1129
3. Weinberg EG Honking: psychogenic cough tic in children. S Afr Med J. 1980; 57:198-200 [Medline]
4. Bernstein L A respiratory tic: the barking cough of puberty. Laryngoscope. 1963; 13:315-319
5. Lokshin M, Lindgren S, Weinberger M, Koviach J Outcome of habit cough in children treated with a brief session of suggestion therapy. Ann Allergy. 1991; 67:579-582 [Medline]
6. Cohlan SQ, Stone SM The cough and the bedsheet. Pediatrics. 1984; 74:11-15 [Abstract/Free Full Text]
7. Lavigne JV, Davis AT, Fauber R Behavioral management of psychogenic cough: alternatives to the "bedsheet" and other aversive techniques. Pediatrics. 1991; 87:532-537 [Abstract/Free Full Text]
8. Bye MR, Kerstein D, Barsh E The importance of spirometry in the assessment of childhood asthma. Am J Dis Child. 1992; 146:977-978 [Abstract/Free Full Text]