9/10 people are affected with pulmonary sarcoidosis at any stage in life, although it most affects those who are 30 to 40 years of age.¹ Pulmonary sarcoidosis is the accumulation of cells that form inflamed lumps known as granuloma, affecting the lungs and lymph nodes in your chest. However, it is important to note that sarcoidosis can occur in any organ. Although this is a rare disease, it is important to understand the signs and symptoms of sarcoidosis to get treatment. Currently, it is unknown what causes pulmonary sarcoidosis, however, several factors have been suggested such as genetic predisposition, infection, and environmental circumstances.² Another suggestion is that the immune system may have gone into overdrive, in which the immune system does not recognise itself, hence it starts to attack tissues and organs resulting in inflammation.¹ The purpose of this article is to provide information on the clinical presentation of the disease, pathophysiology, diagnosis, management, and complications. 

Prevalence and incidence of sarcoidosis

The first case of sarcoidosis was narrated by Jonathan Hutchinson in 1877 as lupus pernio. Eventually, the term ‘sarcoidosis’ was coined by Caesar Boeck when he suspected that the lesions were uncanny to sarcoma.³ Since then, it has been studied that the incidence and prevalence of sarcoidosis are high in Scandinavian countries and among African Americans. However, the incidence of sarcoidosis varies around the world therefore, it is still unknown and difficult to predict estimates of the disease due to the lack of information across countries.⁴ Table 1 illustrates some of the prevalence and incidence of sarcoidosis in different countries since 1990. 

Table 1: shows the reports since 1990 on the prevalence and incidence of sarcoidosis.⁵ 

Clinical Presentation and Diagnosis 

Table 2: illustrates symptoms that are less common in individuals with pulmonary sarcoidosis. 

Pulmonary sarcoidosis can present itself asymptomatically as well as varying symptoms. As mentioned before, pulmonary sarcoidosis is a rare disease, hence it poses challenges in obtaining specific diagnostic criteria due to the lack of information reported.⁶ 

A study reported similarities between chronic beryllium disease (CBD)and pulmonary sarcoidosis, and  even stated that it was able to mimic sarcoidosis in the proportion of cases in the study. The clinical symptoms of sarcoidosis consist of weight loss, night sweats, and persistent dry cough. The most common symptoms reported are shortness of breath and chest pain that is accompanied.

Table 2 demonstrated less common symptoms in patients with pulmonary sarcoidosis. For those who do not experience symptoms, they are usually diagnosed via an X-ray for other reasons. The diagnosis of sarcoidosis is dependent on the clinical features presented on the individuals, for example, three clinical features are used to confirm the diagnosis based on the stage of sarcoidosis showcased using radiographic tools.  

The first clinical feature or stage is bilateral hilar lymphadenopathy (BHL). This is the enlargement of lymph nodes, although this is not a unique characteristic of sarcoidosis. The second stage is Lofgren’s syndrome which is associated with a fever, bilateral hilar adenopathy and erythema nodosum. The third clinical feature is dissimilar to Lofgren’s syndrome known as Heerfordt’s syndrome which is characterised by the enlargement of salivary glands, nerve paralysis on the face and a fever.^8,9 Although radiography is the main diagnostic tool, patients also undergo various examinations to rule out any other similar diagnosis:

• Physical examination: used to demonstrate weight loss, malaise, fatigue, or fever for sarcoidosis.
• Urine analysis: used to diagnose hypercalciuria (an increase in calcium levels which can affect your bones and form kidney stones. 
• Bronchial biopsy and transbronchial lung biopsy: used to observe pulmonary involvement. It can detect the presence of granulomas.⁶
• Tuberculin skin test (Mantoux): ensure the patient does not have tuberculosis.

How does pulmonary sarcoidosis affect the immune system?

The key components involved in the immune system for sarcoid granuloma are T-cells and CD4+ T-cells, in which studies have showcased an exceptionally high increase in the number of activated CD4+ T-cells of patients with sarcoidosis in their lungs.² The prime granuloma pattern in pulmonary sarcoidosis is noncaseating which is surrounded by lymphocytes within the peripheral envelope of lamellar fibrosis. The main sites involved are along the lymphatics in the lung. A granuloma is defined as a cluster of white blood cells and other cells which are a defence mechanism in your body when there is an infection or inflammation.¹¹ Therefore, in sarcoidosis, granuloma formation occurs in the lungs as a response to the unknown trigger of sarcoidosis. Although granulomas are a defence mechanism, accumulating in the lungs leads to inflammation which brings rise to the symptoms previously mentioned such as shortness of breath and chest pain. 

Treatment and management

If an individual is diagnosed with pulmonary sarcoidosis, they usually do not require treatment as the symptoms improve on their own within a timescale of months to a few years. However, if the patient does not improve within three to six months, then treatment may be considered. Alternatively, if symptoms get worse, the individual may have chronic sarcoidosis. As there is no cure for pulmonary sarcoidosis, there are ways to manage symptoms. The individual can take painkillers and get regular X-ray checks. Corticosteroids are also an option if symptoms gradually worsen. They can be taken as a tablet or via inhalation for a related cough. Additionally, steroid tablets can be used to manage symptoms and prevent scarring in affected organs. Unfortunately, taking steroids comes with a lot of side effects, therefore this is usually used as a last resort. Some examples of the side effects include mood swings, weight gain, and osteoporosis. 

How to live with pulmonary sarcoidosis: 

• Quit smoking 
• Regular physical activity 
• Ensure that you get enough sleep: recommended 7-9 hours for adults
• Ensure that you are taking care of your mental health: counselling, visiting a doctor, joining a patient support group

Summary

Overall, pulmonary sarcoidosis is a rare disease characterised by the formation of granulomas, primarily affecting the lungs and chest lymph nodes. While the exact cause remains unknown, some factors may be potential triggers. It is important to identify whether you may have symptoms of pulmonary sarcoidosis to get treatment and management by getting an early diagnosis. 

Maysaah Seif Suleiman

Bachelors of Science Microbiology, BSc Microbiology, University of Reading

I am a recent Microbiology graduate. I have had the opportunity to contribute to two research projects during my time as an undergraduate; in vitro lung models to assess antimicrobial drug activities and discover a potential diagnostic tool for Mycobacterium bovis.

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