Sjögren’s syndrome is a chronic autoimmune condition primarily recognized for its effects on the body’s moisture-producing glands, leading to profound dry eyes and dry mouth. This condition is systemic, meaning the immune system can mistakenly target tissues and organs throughout the entire body. While dryness is the hallmark, many patients experience complications in other systems, including the lungs. Sjögren’s syndrome can cause shortness of breath, and understanding the specific ways this occurs is important for proper management.
How Sjogren’s Directly Affects the Lungs and Airways
The inflammatory process central to Sjögren’s syndrome can directly involve the respiratory system, leading to distinct issues that cause breathlessness. This immune-mediated inflammation can target the large and small airways, as well as the deep lung tissue. Roughly 9–20% of patients with Sjögren’s syndrome experience symptomatic lung involvement.
A serious direct complication is Interstitial Lung Disease (ILD), which involves inflammation and scarring (fibrosis) of the lung parenchyma, the deep tissue surrounding the air sacs. When this tissue scars, it becomes stiff and thick, making it difficult for oxygen to pass into the bloodstream. This results in shortness of breath, particularly with exertion. The most common form of ILD seen in Sjögren’s patients is Non-Specific Interstitial Pneumonia (NSIP).
The small airways (bronchioles) can also be affected by inflammation known as bronchiolitis. This inflammatory infiltration causes obstruction, making it difficult to exhale air efficiently, which manifests as wheezing or breathlessness. Another common complaint is airway dryness, or xerotrachea. Here, the immune attack that affects the salivary glands also dries the mucous membranes lining the trachea and bronchi. This lack of moisture can lead to a chronic dry cough and a sensation of tightness or irritation in the chest.
Other Reasons for Shortness of Breath in Sjogren’s Patients
Not all respiratory symptoms in Sjögren’s patients are due to direct inflammation and scarring of the lung tissue. Several other systemic effects or related conditions can contribute to breathlessness. One issue is pleurisy, which is inflammation of the pleura, the thin membrane lining the lungs and the chest cavity. This condition typically causes sharp chest pain that worsens with deep breaths, often leading to shallow breathing that mimics shortness of breath.
Sjögren’s is frequently accompanied by profound fatigue and muscle involvement, sometimes including myositis (muscle inflammation). This generalized muscle weakness can make breathing, especially during physical activity, feel disproportionately strenuous. The resulting exercise intolerance may be misconstrued as a primary lung problem when it is fundamentally a musculoskeletal or systemic symptom.
The condition can increase the risk of other systemic issues that secondarily impact breathing, such as pulmonary hypertension. This involves high blood pressure in the arteries of the lungs, placing a strain on the heart, which then struggles to pump blood efficiently. Additionally, certain medications used to manage inflammation and the immune response in Sjögren’s, such as immunosuppressants, can have respiratory side effects that may need medical evaluation.
Evaluating Respiratory Symptoms
A thorough evaluation is necessary to determine the specific cause of shortness of breath. The first step involves a detailed clinical history and physical examination, where a physician listens for characteristic sounds like crackles, which suggest underlying ILD. This is often followed by objective tests to measure lung function and visualize the lung tissue.
Pulmonary Function Tests (PFTs) measure how well the lungs are working, including lung volume and airflow. PFTs help distinguish between a restrictive pattern (often seen with ILD) and an obstructive pattern (which points toward small airway disease like bronchiolitis). The diffusing capacity of the lung for carbon monoxide (DLCO) is a specific part of PFTs that measures how effectively oxygen moves from the lungs to the blood, providing an indication of gas exchange impairment.
Imaging studies are also essential, with a High-Resolution Computed Tomography (HRCT) scan being the preferred method to visualize the lung structure. HRCT scans detect the subtle scarring, inflammation, and cystic changes characteristic of Sjögren’s-related lung disease, which may not be visible on a standard chest X-ray. For patients with chronic cough or dyspnea, complete PFTs and HRCT are generally recommended to evaluate for pulmonary involvement.
Treatment Strategies for Sjogren’s Related Lung Issues
The approach to treating respiratory issues depends on the specific type and severity of lung involvement. For active inflammation, such as in Interstitial Lung Disease or severe bronchiolitis, the goal is to suppress the overactive immune response. This typically involves immunosuppressive therapy, often starting with corticosteroids to reduce inflammation.
In many cases, disease-modifying antirheumatic drugs (DMARDs) like azathioprine or mycophenolate mofetil are used alongside corticosteroids or as a steroid-sparing option for long-term management. These medications work to slow the progression of scarring and stabilize lung function over time. For patients with advanced, worsening fibrosis, newer anti-fibrotic medications may be considered to slow the rate of decline.
Symptom management is an important aspect of treatment for non-parenchymal issues. Airway dryness (xerotrachea) may be managed with interventions such as humidification, secretagogues, or specific inhaled medications. Patients with advanced lung disease and low blood oxygen levels may require supplemental oxygen therapy. Pulmonary rehabilitation, a program of exercise and education, can help improve breathing mechanics and quality of life for those with chronic respiratory impairment.