1. Cough, etiology not obvious e.g. pneumonia, sinusitis, etc. Many begin with a chest x-ray. This algorithm is written for, already deemed NOT pulmonary, hence CxR is either not required, or assumed to be negative. The (repeat) CxR half way through the algorithm is usually weeks or even months after the "first" CxR and is either a repeat or if not previously obtained now necessary.
   
   
2. See #3 in Globus algorithm.
   
   
3. See #5 in Hoarseness algorithm.
   
   
4. Antibiotics treat mycoplasma pneumoniae and bronchitis. The usual prescriptions are one of the following:
   1. Erythromycin 330 mgs. P.O. tid x 3 weeks
   2. Doxycycline 50-100 mgs. P.O. bid x 3 weeks
   3. Tetracycline orally for 3 weeks
   4. Second generation macrolides are also excellent treatment.

Overview of Cough

A cough means different things to different specialists. To a psychiatrist this is pertussis nervosa. To a rhinologist it is a symptom of post nasal drip; to a gastroenterologist, a symptom of gastroesophageal reflux disease; to a pulmonologist one of the symptoms of asthma or bronchitis; to the CT surgeon a cough is a symptom of lung cancer; and to the pediatric otolaryngologist, the symptom of an aspirated foreign body. The ENT surgeon sees this as a laryngeal cancer. The infectious disease consultant's top diagnosis would be tuberculosis. To the primary care physician this is a potentially difficult patient.

The algorithm written implies the primary care physician has made a reasonable history and physical exam. If the patient is coughing up blood, this is tuberculosis or cancer. If the patient has aproductive cough and all the other symptoms of pneumonia, the diagnosis is presumably infection. The algorithm is written for those elusive coughs for which no diagnosis is apparent.

Begin with a TB skin test or chest X-ray, simply because all of the treating physicians are going to need to examine the patient carefully. If, in fact, the cough is tuberculous, an unfortunate number of individuals will be needlessly exposed. Those with significant tobacco history require a chest x-ray and an ENT referral.

Assuming no diagnosis is made at this point, the two most common irritative causes are gastroesophageal reflux disease and post nasal drip. If these are excluded by empirical treatment, a chest x-ray (if not already obtained) is now required. Antibiotics are recommended, for often this represents a low grade bronchitis. The antibiotics will treat the infection and generally confirm the diagnosis. When this fails a fiberoptic laryngoscopy is indicated. Assuming this has not been performed, an ENT consultation is required. If this fails to reveal a diagnosis, the last two consultations are pulmonary and psychiatric. These are expensive and therefore saved for last.