PSP typically manifests in young men who are tall, thin, and likely to be smokers [9]. This subtype occurs in ages of 20 to 30 years. However, SSP develops in individuals aged 60 to 65 who exhibit underlying disease.

The presentation typically consists of a sudden onset of sharp pleuritic pain, which may radiate to the neck, shoulder, or abdomen. The pain subsides within 24 hours [10] as the lung adapts by slowly re-inflating.

The features are varied as some patients have mild dyspnea while others develop sequelae such as shock and possibly death. Factors that determine the severity include the amount of air that enters the pleural space, the percentage of lung collapse, and the baseline lung function.

Physical exam

Clinical findings that reflect a large pneumothorax include decreased or absent breath sounds, less movement of the chest wall, tympanic percussion, and reduced tactile fremitus [11]. Additionally, reflex tachycardia is common.

The clinical assessment consists of the patient's history, the physical exam, and the appropriate tests. A large pneumothorax is diagnosed based on the exam findings.

Imaging

A pneumothorax on a chest radiograph is depicted as a collection of air as the collapsed lung is portrayed by a thin line demarcating the pleural edge. Specifically, the upright posteroanterior angle can confirm and accurately determine the size of the pneumothorax [12].

A computed tomography (CT) scan is obtained if the diagnosis is inconclusive. This modality can detect a small pneumothorax and differentiate this from other lung pathologies. CT studies can also be used to monitor the management and progress of these patients.

The treatment of a pneumothorax will depend on the cardiorespiratory status, the severity of the symptoms, and the size of the defect [13] [14]. Mild cases of PSP and SSP are managed through observation while large ones require aspiration or insertion of a chest tube [15]. The latter is indicated if catheter aspiration fails to remove the air or in cases of SSP.

Some patients will warrant surgery, in which a thoracoscope is placed into the pleural space. These individuals will also need high flow oxygen.

Uncomplicated cases do not require treatment and will usually resolve in about 10 days. Recurrences occur especially in smokers and those with COPD or AIDS.

PSP is very likely caused by a ruptured subpleural bleb or bulla [1] [2] whereas SSP develops in those with underlying lung disease such as chronic obstructive pulmonary disease (COPD), cystic fibrosis (CF), infections, congenital disorders, or lung cancer [3] [4].

There may be a genetic component as well. For example, Marfan syndrome, Birt-Hogg-Dube (BHD) syndrome, and homocystinuria have been associated with PSP.

Smoking is a major risk factor as it may elevate the risk by 9 -fold [5].

The incidence of first -time spontaneous pneumothorax in men is 7.4 to 18 patients per a population of 100,000 and in women is 1.2 to 6 per 100,000 [6]. With regards to SSP, the incidence in men is 6.3 cases per 100,000 individuals and in women is 2 cases per 100,000 [7].

Normally, the pressure in the pleural space is negative due to the outward expansion of the chest wall and the intrinsic elastic recoil. Therefore, the chest has a tendency to collapse inward. Hence, when air enters this pleural space, the pressure increases while the vital capacity decreases. Additionally, there is an inverse relationship between the size of the pneumothorax and the volume of the lung. When the former expands, the latter becomes smaller.

The pathogenesis is not uniform in all individuals and has not been established with regards to how ruptured blebs or bullae could cause air to enter the pleural space [8].

Since some patients may experience recurrence. Preventive measures such as surgery may be beneficial in these patients. Surgery involves repairing the weak sites of the lung and strengthening the pleural layers by suturing them to each other.

Spontaneous pneumothorax (SP) refers to the presence of air in the pleural space. It may occur as a primary spontaneous pneumothorax (PSP) or secondary spontaneous pneumothorax (SSP) due to different etiologies. The diagnosis is made clinically with the help of imaging. Management of this condition depends on numerous factors.

What is a spontaneous pneumothorax?

This is a condition in which air enters the space between the chest wall and the lung. It may occur spontaneously, or secondary to lung diseases. Smoking increases the likelihood of developing this especially in individuals in their 20s and 30s.

What are the symptoms?

• Sharp chest pain that spreads to shoulder, neck, or abdomen
• Shortness of breath
• Dry cough

How is it diagnosed?

The clinician will ask the appropriate questions, perform a physical exam and order imaging tests such as chest x-ray and possibly a CT scan.

How is it treated?

Mild cases can be observed without any active treatment . Severe cases will require drainage of the air by either aspiration or insertion of a chest tube.

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