Clinical problem-solving. Nothing to cough at--a 73-year-old man presented to the emergency department with a 4-day history of nonproductive cough that worsened at night

Concentrations of Immunoglobulin G Antibodies Against Pertussis Toxin Does Not Decrease Over a Long Period of Time in Japan

Objective Adult patients with pertussis rarely show typical symptoms, such as paroxysmal coughing, inspiratory "whoop", or post-tussive vomiting. While a culture is regarded as the gold standard for diagnosis, the sensitivity is very low. Therefore, the diagnosis of pertussis in adults in clinical practice is mostly based on single-sample serology using an enzyme-linked immunosorbent assay (ELISA) with the pertussis toxin antigen. Various cut-off values for the anti-pertussis toxin IgG (PT-IgG) have been proposed. It has been reported that concentrations of PT-IgG fall below the defined cut-off about 4.5 months after infection on average, and within 1 year in most patients. We investigated the distribution and time course of the PT-IgG levels. Methods The data were collected from the medical records. Patients The study retrospectively identified subjects who had visited Ikebukuro Otani Clinic, which is a specialized clinic for patients with cough. We retrospectively reviewed 406 patients with PT-IgG measurements to investigate the age distribution of PT-IgG levels. The changes in PT-IgG levels over time were assessed in the 205 patients who had more than one PT-IgG measurement. Results PT-IgG levels were ≥100 EU/mL in more than 15% of subjects. The PT-IgG levels of a few subjects had diminished over a long period of time. Conclusion A PT-IgG level greater than the defined cut-off value simply indicates past infection or immunization in most subjects. As such, a single measurement of PT-IgG using the cut-off values might lead to overdiagnosis of pertussis. Further data collection and analysis are required.

Chronic cough: Stepwise application in primary care practice of the ACCP guidelines for diagnosis and management of cough

PURPOSE

To illustrate decision points encountered when using evidence-based guidelines for diagnosis and management of chronic cough by means of a composite case study based on primary care practice.

DATA SOURCE

The American College of Chest Physicians (ACCP) Evidence-Based Clinical Practice Guidelines for Diagnosis and Management of Cough, and review of the scientific literature on cough and related topics.

CONCLUSIONS

The ACCP guidelines offer a systematic approach that uses trials of empirical therapies to diagnose and resolve the very common, often perplexing complaint of chronic cough. The major diagnoses reached are upper airway cough syndrome, cough-variant asthma, gastroesophageal reflux disease, and nonasthmatic eosinophilic bronchitis.

IMPLICATIONS FOR PRACTICE

Cough is the most common reason that patients seek an office visit. Many coughs resolve spontaneously, but coughs that persist significantly impair the quality of life. Use of the ACCP guidelines allows a stepwise empirical approach to the problem of unexplained chronic cough. This approach greatly increases the percentage of chronic coughs that are accurately diagnosed and effectively treated, and avoids unnecessary diagnostic testing.