Generality
Viral pneumonia is the medical expression that indicates the forms of pneumonia due to viruses.
From the generally benign prognosis, the phenomenon of viral pneumonia is uncommon and usually represents a complication of trivial infections, such as influenza.
Viruses implicated in the onset of viral pneumonia include: influenza virus, parainfluenza virus, adenovirus, respiratory syncytial virus, SARS virus, adenovirus, varicella zoster virus etc.
Viral pneumonia can be diagnosed simply by medical history, physical examination and chest radiography; however, doctors often resort to further investigations, to better frame the present situation.
The treatment of viral pneumonia varies from patient to patient, depending on factors such as age, health status, timing of diagnosis and severity of symptoms.
Brief review of the medical meaning of the term pneumonia
In medicine, " pneumonia " refers to any lung disease characterized by the inflammation of the alveoli . Also known as pulmonary alveoli, the alveoli are the small sacs located at the end of the bronchial tree, in which the air introduced with the inspiration and in which the extraction, by the human organism, of the oxygen contained in the aforementioned air.
What is Viral Pneumonia?
A viral pneumonia is a pneumonia due to a virus that is able to enter, through the mouth or nose, into the airways, reach the pulmonary alveoli and infect them.
As will be seen in the chapter on causes, the phenomenon of viral pneumonia is a possible complication of the action of viruses responsible for infections in some cases, even very trivial and common (eg: influenza); this means, indirectly, that there is no real pneumonia virus (as is the case for bacterial pneumonia ).
The episodes of viral pneumonia are examples of atypical pneumonia, namely the particular infectious pneumonia due to pathogens different from those usually involved in inflammatory processes affecting the pulmonary alveoli.
Is it serious?
Viral pneumonia is not a serious condition, but nevertheless it still deserves the doctor's due attention ; in fact, it is a condition that, in some situations, can degenerate to the point of being very dangerous for the patient's safety, if not fatal.
Epidemiology
According to some statistical studies, every year around the world, around 200 million people, of which half are children and half are adults, suffer from viral pneumonia.
Causes
The list of viruses capable of causing viral pneumonia is rich and includes three groups of pathogens:
- The group with the influenza A virus, the influenza B virus, the respiratory syncytial virus and the human parainfluenza virus.
This is the group that collects the most widespread causes of viral pneumonia in the general population .
- The group with the adenovirus, the metapneumovirus, the SARS virus (where SARS stands for "Severe Acute Respiratory Syndrome") and the MERS virus (where MERS stands for "Middle Eastern Respiratory Syndrome").
This is the grouping that collects the causes of viral pneumonia less common in the general population .
- The group with herpes simplex virus, varicella-zoster virus, measles virus, rubella virus, cytomegalovirus, smallpox virus and dengue virus.
This is a group reserved for all those viral agents that cause, as a primary effect, diseases without any relation to the lungs and, as a very rare secondary effect, a form of pneumonia.
Risk Factors of Viral Pneumonia
Anyone can develop viral pneumonia; however, statistics show that this particular form of pneumonia is more frequent among:
- People over the age of 65;
- Individuals under the age of 2;
- People with chronic respiratory diseases (eg, COPD and asthma);
- Immunosuppressed, that is, subjects with reduced immune defenses (eg: AIDS patients and patients with cancer undergoing chemotherapy);
- Pregnant women;
- Smokers
- Who has recently contracted a viral infection of the airways (eg, a cold).
Contagiousness and Transmission
Viral pneumonia is a contagious infectious disease, as the viruses that cause it are capable of being transmitted to a receptive subject without the intervention of a carrier or the occurrence of particular circumstances.
TRANSMISSION MODE
The transmission to a healthy individual of the most classic viruses that cause viral pneumonia usually occurs through contact with contaminated objects or the inhalation of infected saliva droplets, emitted by a patient, during sneezing, coughing or when speaking .
Symptoms and Complications
Viral pneumonia is a condition with mild symptoms and a less severe impact on the health of the patient, compared to the more classic bacterial pneumonia (eg: Streptococcus pneumoniae pneumonia ).
Typical symptoms and signs of viral pneumonia include:
- Cough with yellow or green phlegm production;
- Temperature;
- Chills;
- Sense of fatigue;
- Profuse sweating;
- Dyspnea (ie breathlessness);
- Chest pain, which gets worse on coughing and deep breathing;
- Cyanotic lips (in other words, they take on a bluish color);
- Headache;
- Widespread muscle pain (diffuse myalgia);
- Generalized weakness and lack of strength.
In symptoms, viral pneumonia and bacterial pneumonia are similar to each other, except for diffuse myalgia and headache, two exclusive symptoms of alveolar inflammation due to viruses.
Viral pneumonia in children
In children, in addition to the aforementioned manifestations, viral pneumonia could be the cause of: cyanosis, loss of appetite and difficulty in eating (only in very young children).
Viral pneumonia in the elderly
In the elderly, viral pneumonia adds disorders to the classic symptomatology such as confusion, dizziness and vertigo .
When should I go to the doctor?
Viral pneumonia requires immediate medical intervention when its deterioration leads to:
- Severe confusion;
- Increased respiratory rate;
- Barking cough;
- Sudden drop in blood pressure;
- Severe breathing difficulties;
- Fever above 38 ° C, which shows no signs of descending;
- Intense and constant chest pain;
- Clear cyanosis.
Curiosity: on what do respiratory difficulties and cyanosis depend?
The respiratory difficulties and cyanosis observed during viral pneumonia are the consequence of the inability of the inflamed alveoli to draw oxygen from the inhaled air.
Complications
Although it happens very rarely, the following complications can arise from viral pneumonia:
- Brain and nervous system infections, such as encephalitis, meningitis or myelitis;
- Hemolytic anemia ;
- Severe damage to the lung tissue, resulting in chronic conditions such as COPD.
Diagnosis
To formulate the diagnosis of viral pneumonia are sufficient: the anamnesis, the physical examination and the images of the lungs provided by a chest radiograph ( RX-thorax ).
However, it is not uncommon for the diagnostic doctor to look into the situation, using:
- Oximetry and blood gas analysis, to know the levels of oxygen and carbon dioxide in the blood;
- Blood tests, to know precisely what is the viral agent involved in the inflammation of the alveoli;
- The cultural examination of the sputum, to exclude that bacterial pneumonia is in progress;
- A magnetic resonance imaging ( MRI ) or chest CT scan, to obtain even more detailed images than those provided by the RX-chest;
- Bronchoscopy . It is used very rarely and, only, when doubts remain about the current condition.
history
A medical history useful in identifying viral pneumonia involves a careful examination of the symptoms, combined with an investigation into elements such as: the age of the patient, his past medical history, his habits and his general state of health.
Physical examination
A physical examination useful for the detection of viral pneumonia includes: measurement of body temperature, measurement of respiratory rate and pulse, and auscultation of the chest to assess breath quality.
Physical examination in a person with viral pneumonia brings to light: wheezing and abnormal noises during breathing, the presence of a rapid heartbeat and labored breathing.
Chest X-ray
Chest X-ray represents the diagnostic confirmation of what is only assumed with previous investigations. The chest X-ray, in fact, allows to recognize an inflammation of the alveoli and distinguish it from all the other pulmonary pathologies that, in spite of the different nature, cause very similar symptoms.
How to distinguish Viral Pneumonia from classic Bacterial Pneumonia
In the diagnostic field, the parameter that allows doctors to distinguish viral pneumonia from classical bacterial pneumonia is the degree of severity of the symptomatology, which is, as already stated, decidedly more tenuous in the first case.
Therapy
The treatment of viral pneumonia could:
- Limit yourself to a simple supportive care, based on absolute rest in the comfort of the home, on the constant supply of fluids and on the use of anti-inflammatories / analgesics (paracetamol or NSAIDs) to mitigate any pain.
Such a therapeutic approach is indicated when the patient is an adult, young or in any case not old, in good general health (he does not suffer from chronic diseases or from a state of immunodepression), which presents excellent resilience;
or
- Combine the countermeasures listed above with the use of a specific antiviral drug .
For the implementation of this therapeutic plan the assumptions of the previous point (adult patient in good health) and the occurrence of particular situations, such as, for example, an early diagnosis or a serious symptomatology are fundamental.
or, finally,
- Need those therapies that only one hospitalization can provide.
This therapeutic approach is indispensable when the patient is a very young child, an elderly person, a person with a chronic illness, an immunodepressed subject (ie with a deficient immune system) or an individual who, due to very intense symptoms, fails to drink and take care of yourself properly.
In essence, the treatment of viral pneumonia varies from patient to patient, depending on factors such as:
- The age;
- The state of health;
- The timing of the diagnosis;
- The severity of the symptoms.
Antiviral therapy: how is the drug chosen?
The choice of the antiviral drug depends on the type of virus that caused the viral pneumonia present. For example, antiviral drugs oseltamivir or zanamivir are used during a pneumonia virus due to influenza A or influenza B. during a viral pneumonia due to respiratory syncytial virus, ribavirin is applied; during a viral pneumonia due to the herpes simplex or varicella-zoster virus, acyclovir is indicated; in the presence of viral pneumonia due to cytomegalovirus, ganciclovir is used; etc.
Curiosity
For cases of viral pneumonia due to coronavirus (eg SARS virus) there is still no antiviral drug suitable for counteracting the infection.
Prognosis
Viral pneumonia tends to have a benign prognosis .
The situations most at risk of a negative prognosis are those in which the patient is an elderly person, a frail person or a child who does not receive timely and adequate care; in such circumstances, the expression negative prognosis also includes the patient's death.
What are the healing times?
For an adult patient, but not elderly, and in good health, complete recovery from viral pneumonia takes 1 to 3 weeks ; for a young patient or an elderly and for those suffering from a chronic illness, instead, it needs more time (certainly more than 3 weeks).
Prevention
To prevent viral pneumonia, people at risk of it should: get vaccinated against the flu, wash their hands regularly, avoid smoking, eat healthy and stay away from people with infections associated with viral pneumonia (eg, sick of influence).
