Pulmonary sarcoidosis is categorised as a multisystem inflammatory disorder which is caused by the formation of granulomas (clusters of immune cells). This can happen in various organs, however, the most commonly affected are the lungs. Although the cause of sarcoidosis is not fully known, it is believed that it involves a combination of environmental factors and genetic predisposition.

While sarcoidosis can affect any age group (rare in childhood), it is typically seen in adults aged between 30 and 40.¹ Most often chest pain occurs as a result of this condition which can be very uncomfortable. Read on to find out more about pulmonary sarcoidosis, resulting chest pain its pathophysiology, symptoms, treatments, and long-term outcomes. 

Introduction

Definition of Pulmonary Sarcoidosis 

Sarcoidosis is a rare condition that causes granulomas, which are small patches of swollen tissues. In most cases it affects the lungs and lymph nodes, although it can happen in any organ system.¹ A key part of how sarcoidosis development is the involvement of T cells in the promotion of cellular immune reaction. Additionally, studies have revealed increased activity of tumour necrosis factor (TNF) and TNF receptors.²

What all this means is that the body effectively attacks its own tissues, as is common in autoimmune conditions. This disease causes a hyperactive immune system that result in chronic inflammation and thus granuloma development.¹

Symptoms 

It can be difficult to determine how sarcoidosis will affect an individual. In most cases, the symptoms are developed suddenly but usually clear themselves in a few months, which is called ‘acute sarcoidosis’. However, in rare cases a person may find their symptoms gradually develop and get worse as time passes. If a granuloma becomes big enough it will stop the particular organ from working as it should, which is called ‘chronic sarcoidosis’.¹

In the case of pulmonary sarcoidosis, where a granuloma forms in the lung the symptoms can include: 

• Shortness of breath 
• Persistent dry cough 
• Pain and discomfort in the chest 

While some people may experience chest pain it a more uncommon symptom. 

Chest pain in pulmonary sarcoidosis 

In pulmonary sarcoidosis, chest pain can manifest itself in multiple forms. This reflects the ways in which the disease affects the lungs. 

Pleuritic chest pain 

Pleuritic chest pain is the most common symptom associated with the condition. It is most common in the substernal and intrascapular areas. It is described as being a sharp, stabbing pain that worsens with deep breathing or coughing.³

When there are granulomas present in the pleura (thin membrane that lines the chest cavity), it leads to inflammation and subsequent irritation. In a CT scan study, it was revealed that most chest pain in pulmonary sarcoidosis was not related to specific lung lesions. However, when observing pleural lesions specifically, it was noted that on occasion chest pain could be associated.⁴

Costochondral chest pain

Occasionally, costochondral rib junctions and joints of the chest wall will become inflamed in persons with sarcoidosis. This complication can sometimes be referred to as ‘Tietze syndrome’.⁵ This creates intense pain that radiates throughout the chest cavity.

It is described as tenderness and discomfort due to the inflamed cartilage connecting the ribs to the sternum. The mechanism behind this pain is granulomatous inflammation similarly to other types of chest pains in sarcoidosis. Pain is exacerbated by movement and/or palpation.⁵

Chest tightness 

Feelings of chest tightness can be common in pulmonary sarcoidosis and is often described as feeling a pressure sensation in the chest as if someone is squeezing it. As opposed to the other types of chest pain, this symptom develops due to granulomatous inflammation within the lung tissue. Consequently, it causes airway constriction and can arise especially during physical exertion or breathing deeply.⁴

Factors influencing severity of chest pain 

Degree of inflammation 

The degree of chest pain severity can depend on the extent of inflammation within the lungs and/or surrounding areas due to granulomas. While some studies suggest that there is little correlation between granuloma development within the lungs and onset of chest pain, it is agreed that certain specific areas of inflammation in the lungs are responsible.⁴

Granuloma formation 

The biggest characteristic of pulmonary sarcoidosis is the formation of granulomas. Therefore, the size, number, and location of these clusters of immune cells are associated with chest pain severity. This being that the bigger or the more granulomas are present, the more severe the chest pain, especially if present in particularly damaging areas of the lungs.⁶

Disease progression

The stage of the disease and its influence overtime has been shown to have influence on chest pain severity. Although not in all cases, in some, chest pain worsens as the disease advances and damages more lung tissues. In rare cases, a pneumothorax (an abnormal collection of air in the pleural space) can occur due to necrosis of subpleural granulomas or potentially from a rupture of a cystic lesion in later stages of the disease.⁴

Comorbidities

Unsurprisingly, the presence of other diseases can affect chest pain severity such as asthma, chronic obstructive pulmonary disease (COPD), or cardiovascular disease. These are all examples of conditions that can exacerbate chest pain in pulmonary sarcoidosis patients. 

Environmental factors 

Other than disease states, there are many lifestyle factors which can affect chest pain severity. These include smoking, stress, and/or high levels of physical activity. It is commonly known that smoking puts incredible strain on the normal functioning of the lungs. In the case of pulmonary sarcoidosis, smoking simply adds to lung inflammation and worsening of respiratory symptoms which in turn take their toll on chest pain severity. 

Clinical manifestations of pulmonary sarcoidosis

Abnormal chest imaging

According to clinical documentation, approximately half of all patients are diagnosed incidentally with pulmonary sarcoidosis during routine chest imaging performed for unrelated conditions.⁷

Pulmonary symptoms 

In roughly 90 to 95 percent of patients with pulmonary sarcoidosis there is involvement of the lung or thoracic lymph nodes. There could be a range of presenting symptoms including cough, dyspnoea (laboured breathing), fatigue, and of course chest pain. 

There are conflicting reports on the association between location of granulomas and chest pain severity. While there are some studies that suggest there are strong correlations⁶, others suggest that the location or severity of chest pain is not related to the location or extent of granulomatous lesions.⁷ Pulmonary symptoms are often accompanied by systemic manifestations such as fatigue, fever, and weight loss, especially in elderly patients.⁷

Evaluation and diagnosis 

Medical history 

There is some evidence that suggests that genetic predisposition plays a role in sarcoidosis development. Family history studies have shown that individuals with affected family members are at a higher risk of developing sarcoidosis.⁶ Additionally, ethnicity and geographic location has been shown to be associated factors. It has been reported that individuals with African descent and those with Northern European ancestry are at a higher risk for sarcoidosis. On the other hand, lower rates are observed in Asian and Hispanic populations.⁶

As sarcoidosis is an autoimmune disorder, dysfunction of the immune system such as dysregulation of cytokines and T-cell activity can increase chances of developing the condition. 

Laboratory examination

To diagnose pulmonary sarcoidosis, a doctor could request any number of blood tests which include looking for elevated levels of substances such as blood urea nitrogen, creatinine, glucose, electrolytes, and serum calcium. Moreover, elevated serum alkaline phosphatase concentration can suggest granulomatous development.² 

Imaging tests 

As discussed, pulmonary imaging is by far the best way to diagnose pulmonary sarcoidosis. Imaging techniques such as chest X-rays or CT scans are often very specific. Should the imaging not provide enough information on a patient’s condition, a doctor could choose to examine the inside of the lungs to paint a more complete picture.¹ This is done by using a bronchoscope which is a long, thin, flexible tube with a camera. 

Tissue biopsy 

If a definitive diagnosis cannot be made, a doctor could choose to perform a transbronchial biopsy of the affected tissues. Although the procedure is not without risks, it can provide a very clear profile of the diseased tissues and provide a final diagnosis while also ruling out other possible conditions. 

Management and treatment 

Pulmonary sarcoidosis is not only rare, but in most cases the condition simply goes away on its own. However, in some cases, the condition lingers, progresses, and worsens. Unfortunately, the condition is often asymptomatic and patients would not know they have it unless incidentally undergoing imaging as previously mentioned. 

Common painkillers

According to the NHS, the first line of treatment is simply managing the symptoms with common painkillers such as paracetamol and ibuprofen. Doctors will monitor the patient’s condition without starting treatment which is done with regular X-rays, breathing tests, and blood tests.¹

Steroid tablets 

Should symptoms worsen, a doctor will recommend steroid tablets such as glucocorticoids to reduce inflammation and prevent scarring of the lung tissue which would be irreversible. Due to the harsh nature of steroids, in some cases it is recommended to take calcium or vitamin D supplements to reduce the risk of osteoporosis caused by long-term steroid use.^1,2

Summary

Pulmonary sarcoidosis is a rare, but harmful autoimmune condition in some cases. While most cases are seen to simply fade away over time, there are some cases which remain and progress into something more sinister. 

Chest pain can be very uncomfortable to live with in this condition, although it has been observed to be an uncommon symptom. Most importantly, if you have any symptoms which seem to persist over time, it is crucial to consult your doctor for next steps.