Pneumonia vs. Walking Pneumonia

Before answering the above questions, I want the reader and myself to be on the same initial page and agree that the basic subject about to be presented is pneumonia. Pneumonia is a disease of the lung tissue that involves inflammation of the alveoli (air sacs in the lungs where O₂ and CO₂ are exchanged). Although bacteria and viruses cause the majority of pneumonias, there can be other causes such as fungi, parasites, chemicals, and physical injury to the lung tissue. Pneumonias can result in fluid accumulation in alveoli (congestion, with poor gas exchange) and produce the typical signs and symptoms of cough, shortness of breath, and often fever and chest pain, especially when coughing.

Pneumonia is not bronchitis (inflammation of the bronchial tissue), and it's not pleurisy (inflammation of the pleural lining of the lungs and chest), although both can produce some symptoms similar to pneumonias. Please note the use of the word "pneumonias"; it's plural and, in my view, has many different words (over 30, including the veterinary literature) used in both the lay and medical literature to identify subsets of the disease. Unfortunately, this can lead to confusion because there is a considerable amount of imprecision and overlap with these modifiers. We in the medical professions are guilty of developing and then using them; I don't see any evidence that the terminology will improve, so I'll try at least to indicate what several of the prominent pneumonia modifiers mean (and don't mean) and answer the questions asked above in the title.

• Infectious pneumonia (bacterial, viral, fungal, and parasitic are all subsets of infectious pneumonia) means that an infectious agent is causing the pneumonia.
• Chemical pneumonia (many types caused by various substances such as chlorine or gasoline fumes) means that the pneumonia results from an irritant, not an infectious or traumatic cause.
• Traumatic pneumonia (trauma such as a blunt object striking the chest as in an auto accident or an assault) is a noninfectious or nonchemical cause of lung tissue inflammation.
• Walking pneumonia (First question answer: Pneumonia doesn't walk, but patients with "walking pneumonia" do!) is an imprecise term used to describe a person with symptoms of pneumonia that are "mild" enough to allow people to do daily activities and do not require patient hospitalization; it does not describe the cause of the pneumonia-like symptoms and is often used as a preliminary diagnosis without good evidence (a chest X-ray or other tests) that pneumonia is actually present. The major difference between pneumonia and walking pneumonia are the severity of symptoms, with walking pneumonia having the least severe symptoms in most individuals.
• Double pneumonia (Second question answer: Double pneumonia is not double talk, but means that both the right and left lung has pneumonia.) means at least two lung lobes (one on the right lung and one in the left) have pneumonia. The term implies a more severe pneumonia, but the term is imprecise as it doesn't indicate the cause or how severe the pneumonia is.
• Atypical pneumonia: The meaning of this word is unfortunately multiple, and it changes depending on the context in which it is used. For example, atypical pneumonia is used by some medical personnel to mean mild or "walking" pneumonia, while others use it to describe pneumonia caused by Mycoplasma pneumoniae. Still others use the modifier to refer to all pneumonias caused by pathogens from birds that can also infect humans.
• Community acquired pneumonia is pneumonia acquired outside of a hospital setting; although usually bacterial and sometimes antibiotic resistant, the term does not describe the cause.
• Hospital acquired pneumonia is pneumonia acquired during a hospital stay; it's usually bacterial and often antibiotic resistant, but the term again does not describe the cause.
• Lobar pneumonia is pneumonia that at least in one (and often more) of the lobes of the lung, is consolidated, and is considered a more severe form of pneumonia, no matter what the cause.
• Aspiration pneumonia is pneumonia caused by inhaling foods, saliva, vomit, or gastric contents that can act as both a chemical and infectious cause of pneumonia.

Because walking pneumonia was supposed to be a focal point of this article, and I've given my view as to what it is and is not, the rest of this article will focus on how walking pneumonia is often viewed by clinicians who diagnose and treat the disease. First, the symptoms of walking pneumonia are mild -- usually a cough that can be frequent with little or no phlegm (also termed a dry cough), a low or absent fever (usually under 101 F), and feeling more tired after normal activities or simply have tiredness or fatigue. Some patients may get muscle aches or back aches, an occasional rash, appetite loss, and/or headaches. The symptoms are present for a few days usually before patients seek medical care because "the symptoms are not too bad but they just seem not to go away." In addition, many patients have additional problems such as sinus infections, sore throats, or asthma.

Most of these symptoms can occur in both adults and children; however, children may appear more short of breath than adults. Many physicians will do a chest X-ray to help obtain evidence for a presumptive diagnosis, but others will not. Mycoplasma pneumoniae is considered the major cause of walking pneumonia by many clinicians, but it is seldom confirmed by any test. Consequently, many clinicians will give an antibiotic such as doxycycline (Vibramycin, Oracea, Adoxa, Atridox) to treat the presumed Mycoplasma infection. If the "walking pneumonia" is due to Mycoplasma, the antibiotic will help rid the person of the infection and make the person either less contagious or noncontagious. However, if the cause is not Mycoplasma, the antibiotic may not help at all. In general, walking pneumonia can be contagious for up to about a month if treatment is not given. The symptoms or recovery time also can last about a month or so if the patient is not treated.

Walking pneumonia can abate without antibiotics and the person usually recovers with no lingering problems, but occasionally symptoms become worse. Children, pregnant females, the elderly, and immunocompromised patients should seek medical care if they develop symptoms of walking pneumonia because they can more easily progress to the more severe forms of pneumonia. Some people with suppressed immune systems may seem to have walking pneumonia but actually have pneumonia caused by agents like Pneumocystis jiroveci (formerly known as Pneumocystis carinii), a fungal cause of chronic pneumonia that initially causes symptoms that resemble those of walking pneumonia.

In my view, the term "walking pneumonia" just does not give the patient enough information about their symptoms. Patients with this diagnosis should ask their doctors to please explain why they are told this is their problem and what type of follow-up is required.