Pulmonary Tuberculosis Differential Diagnosis Table

Pulmonary Tuberculosis Differential Diagnosis Table:

Pulmonary Tuberculosis is one of the two forms of Tuberculosis. Tuberculosis is an infectious disease caused by a group of bacteria of the family Mycobacteriaceae. It is a systemic disease that mostly affects the respiratory system. Pulmonary Tuberculosis is defined as tuberculosis that affects the pulmonary parenchyma.
It is estimated that one third of the world’s population is infected with Koch’s bacillus. The main risk factors for acquiring pulmonary tuberculosis are: Diabetes, HIV, malnutrition, migrant population, health personnel, as well as living with a person who has the disease.

The transmission of this disease occurs directly from person to person. The infected person eliminates these bacilli through droplets that are generated, then evaporate and become aerosols of small particles. Therefore, being so small in size they remain in suspension and are carried by the air flow. When a healthy person inhales this bacilli charge causes these bacilli to reach the pulmonary alveoli. Prolonged and intimate contact is necessary for contagion to occur. After the exposure, 5% of those infected develop the disease in the next two years and another 5% in following years.

There are people who are infected with this disease and do not show symptoms until years later when, for some reason, their immune system is compromised. There are other forms of transmission such as digestive, oral-fecal although the most common is pulmonary.

Pulmonary Tuberculosis presents an insidious onset with productive cough for more than 15 days, asthenia, night sweats, hemoptysis, high fever and weight loss.
On consultation, this is a patient who presents looking acutely ill, complaining of cough, severe chest pain, appetite and weight loss and very high fever, also chills as well.

How to Distinguish Pulmonary Tuberculosis from Other Diseases

Distinguish Bacterial Pneumonia from Pulmonary Tuberculosis – Diagnosis

Is an infection of the lungs caused by bacteria.

• Bacterial Pneumonia, unlike Pulmonary Tuberculosis, does not have a single etiologic agent, but can be caused by different bacteria.
• Bacterial Pneumonia, unlike Pulmonary Tuberculosis, is not a contagious disease that is passed from person to person.
• Bacterial Pneumonia, unlike Pulmonary Tuberculosis, is a rapidly evolving infection. It has an incubation period of 48 to 72 hours before presenting symptoms.
• Bacterial Pneumonia symptoms are high fever, yellow or green sputum, dyspnea, tachycardia, and tachypnea while Pulmonary Tuberculosis symptoms are productive cough for more than 15 days, asthenia, night sweats, hemoptysis, high fever, and weight loss.
• In an X-ray with a patient with Bacterial Pneumonia, infiltrates or consolidations in the affected lung are visualized while in Pulmonary Tuberculosis there may be evidence of cavitations in the lung apex.
• The treatment for Bacterial Pneumonia lasts about 8 days and the patient presents a good resolution in 3 or 4 days unlike Pulmonary Tuberculosis in which the recovery is slower and the treatment lasts 6 months.

Distinguish Viral Pneumonia from Pulmonary Tuberculosis – Diagnosis

Is an infection of the lungs caused by viruses.

• Viral Pneumonia, unlike Pulmonary Tuberculosis, is caused by viruses.
• Viral Pneumonia, unlike Pulmonary Tuberculosis, is more common in children.
• Viral Pneumonia symptoms are general malaise, rhinitis, headache, and muscle aches while Pulmonary Tuberculosis symptoms are productive cough for more than 15 days, asthenia, night sweats, hemoptysis, high fever, and weight loss.
• Viral Pneumonia is treated symptomatically while Pulmonary Tuberculosis requires treatment with antibiotics.

Distinguish Lung Carcinoma from Pulmonary Tuberculosis – Diagnosis

It’s a cancer that occurs in the cells of the lung.

• Lung Carcinoma is due to an uncontrollable proliferation of lung cells while Pulmonary Tuberculosis is due to a bacterial infection.
• In Lung Carcinoma, unlike Pulmonary Tuberculosis, there is no presence of sputum.
• The most common risk in Lung Carcinoma, unlike Pulmonary Tuberculosis, is tobacco.
• Lung Carcinoma is diagnosed by a chest CT, unlike Pulmonary Tuberculosis which is diagnosed by a sputum culture.

Distinguish Histoplasmosis from Pulmonary Tuberculosis – Diagnosis

It´s a fungal infection.

• Histoplasmosis is caused by the inhalation of the spores of the fungus found in the fecal matter of birds and bats, unlike Pulmonary Tuberculosis which is transmitted through respiratory droplets when the infected person speaks, coughs, or sneezes.
• In Histoplasmosis, unlike Pulmonary Tuberculosis, there is the presence of dry cough.
• Histoplasmosis is due to a fungal infection while Pulmonary Tuberculosis is due to a bacterial infection.

Distinguish Coccidioidomycosis from Pulmonary Tuberculosis – Diagnosis

It´s a fungal infection.

• Coccidioidomycosis is caused by the inhalation of the spores of the fungus found in the air through agricultural work or when the wind drags the spores, unlike Pulmonary Tuberculosis which is transmitted through respiratory droplets when the infected person speaks, coughs, or sneezes.
• Coccidioidomycosis is due to a fungal infection while Pulmonary Tuberculosis is due to a bacterial infection.
• Coccidioidomycosis, unlike Pulmonary Tuberculosis, presents joint pain and a red rash.

Distinguish Blastomycosis from Pulmonary Tuberculosis – Diagnosis

It´s a fungal infection.

• Blastomycosis is caused by the inhalation of the spores of the fungus found in the infected soil, unlike Pulmonary Tuberculosis which is transmitted through respiratory droplets when the infected person speaks, coughs, or sneezes.
• Blastomycosis is due to a fungal infection while Pulmonary Tuberculosis is due to a bacterial infection.
• Blastomycosis treatment is based on antifungals while Pulmonary is based on antibiotics.

Common Red Flags with Pulmonary Tuberculosis

One person infected with Pulmonary Tuberculosis can infect 10 to 15 people in a year. The only form of tuberculosis that can infect another person is Pulmonary Tuberculosis; latent or extrapulmonary tuberculosis cannot infect another person.

The diagnosis of Pulmonary Tuberculosis may be suspected by a random chest X-ray, but it’s confirmed microbiologically by bacilloscopy and Koch culture. Koch’s culture is the reference test or the standard that allows establishing the diagnosis of Tuberculosis. This bacteriological study consists of serial samples of morning sputum for 3 days in which the presence of acid-fast bacilli must be demonstrated.

Tuberculosis is a curable disease which has pharmacological treatment whose objectives are to interrupt the chain of transmission and prevent complications and sequelae.

The treatment must be administered and strictly supervised. It consists of 2 phases. Phase 1 (Intensive phase): Lasts 2 months in which 4 drugs are: Isoniazid(300mg), Rifampicin(600mg), Pyrazinamide(1500mg), and Ethambutol(800mg) 60 doses and is taken daily from Monday to Saturday with rest on Sundays. Phase 2 (Support phase): Lasts 4 months in which 2 drugs are: Isoniazid(600mg) and Rifampicin(600mg), 45 doses, is taken on Monday, Wednesday, and Friday.

The prognosis of this disease is excellent as long as the patient has good access to treatment. The factors that condition a worse prognosis and higher risk of mortality are: extreme age, miliary tuberculosis, co-infection by HIV.

Tuberculosis can be prevented by BCG vaccine applied in newborns to prevent severe forms of this disease such as tuberculous meningitis, but it does not prevent the infection of Pulmonary Tuberculosis. Another method of prevention is chemoprophylaxis to people at risk of being infected as health personnel or people who live with persons with the active disease or have some risk of suffering from it.