Connective Tissue Diseases
MBChB (New Zealand), PGDipObstMedGyn, FRACP (New Zealand), FAMS (Rheumatology)
Connective tissue diseases (CTDs) are a group of autoimmune rheumatic conditions in which the immune system inappropriately attacks the body’s own tissues and organs, causing inflammation and, in some cases, tissue damage. CTDs can involve multiple parts of the body, including the skin, joints, muscles, lungs, kidneys, heart and blood vessels.
Symptoms can develop gradually and vary significantly from person to person, which can make connective tissue diseases challenging to recognise in their early stages. Early diagnosis is important, as appropriate treatment can help control inflammation, relieve symptoms and reduce the risk of long-term joint or organ damage.
At the Centre for Rheumatology & Arthritis, Dr Poh performs a comprehensive assessment to establish an accurate diagnosis and develops a personalised treatment plan tailored to your condition, symptoms and individual healthcare needs.
Common Autoimmune Connective Tissue Diseases
Although autoimmune connective tissue diseases share many overlapping symptoms, each condition can affect the body differently. Common connective tissue diseases include:
Lupus (Systemic Lupus Erythematosus)
Lupus is a chronic autoimmune disease that can affect many different organs such as the skin, joints, kidneys, lungs, heart, nerves and blood cells. Common symptoms include joint pain and swelling, skin rashes, mouth ulcers, fatigue and sensitivity to sunlight.
Sjögren's Syndrome
Sjögren's syndrome is a chronic autoimmune condition that primarily affects the glands responsible for producing tears and saliva, often causing dry eyes and dry mouth. It may also be associated with fatigue and joint pain. In some people, Sjogren’s syndrome can affect other parts of the body, including the lungs, kidneys and nervous system.
Scleroderma (Systemic Sclerosis)
Scleroderma is a chronic autoimmune disease characterised by abnormal immune system activation and excess collagen production. This can cause the skin to become thickened and tight. In some people, it may also affect the joints, muscles, lungs, digestive tract, heart and kidneys.
Myositis (Idiopathic Inflammatory Myopathy)
Myositis refers to a group of rare autoimmune conditions that cause inflammation and damage to the muscles, leading to muscle weakness and fatigue. Common forms include dermatomyositis and polymyositis. Dermatomyositis is also associated with characteristic skin rashes, while some people may develop problems affecting the lungs, joints or swallowing muscles.
Mixed Connective Tissue Disease (MCTD)
Mixed connective tissue disease is a rare autoimmune condition with overlapping features of lupus, systemic sclerosis and inflammatory myositis. Common symptoms include Raynaud's phenomenon, joint pain and swelling, swollen fingers and hands and muscle weakness. Some people may also develop skin changes, difficulty swallowing, heartburn or lung involvement.
Undifferentiated Connective Tissue Disease (UCTD)
Undifferentiated connective tissue disease refers to a group of autoimmune conditions in which a person has symptoms and blood test findings suggestive of a connective tissue disease, but does not meet the criteria for a specific diagnosis such as lupus or scleroderma. Symptoms vary between individuals and may include joint pain or swelling, Raynaud’s phenomenon, fatigue, muscle aches, dry eyes or mouth and skin changes. Some people remain stable with mild symptoms, while others may develop features of a more clearly defined connective tissue disease over time.
Conditions Associated with Connective Tissue Diseases
Autoimmune connective tissue diseases can affect different parts of the body, including organs beyond the joints and muscles. Some people may develop organ involvement that requires regular monitoring and, where appropriate, coordinated care with other medical specialists. Regular follow-up helps ensure that treatment is tailored to each person’s needs and that any complications are recognised and addressed early.
Interstitial Lung Disease (CTD-ILD)
Some connective tissue diseases can affect the lungs, causing inflammation and scarring known as interstitial lung disease (ILD). Symptoms may include a persistent dry cough, shortness of breath and reduced exercise tolerance. Early recognition and regular monitoring are important, as timely assessment and treatment may help preserve lung function and reduce the risk of disease progression.Pulmonary Arterial Hypertension (CTD-PAH)
Certain connective tissue diseases, particularly scleroderma and mixed connective tissue disease, can cause pulmonary arterial hypertension (PAH). PAH occurs when the pressure in the blood vessels that carry blood from the heart to the lungs become abnormally high. Symptoms may include shortness of breath, reduced exercise tolerance and fatigue.Raynaud's Phenomenon
Raynaud's phenomenon causes the fingers or toes to change colour in response to cold temperatures due to temporary narrowing of the small blood vessels. It can occur on its own or be associated with an underlying connective tissue disease. In some people, particularly when symptoms are new or more pronounced, Raynaud’s may be an early sign of an autoimmune condition and may warrant further assessment.
Causes and Risk Factors of Connective Tissue Diseases
The exact causes of connective tissue diseases are not fully understood. They are thought to develop through a combination of genetic susceptibility, immune system dysregulation and environmental factors. The contribution of these factors varies between different connective tissue diseases.
Genetic Susceptibility
Having a family history of an autoimmune or connective tissue disease may increase a person’s susceptibility to developing these conditions. However, connective tissue diseases are generally multifactorial, meaning that genetic factors interact with other influences rather than determining whether someone will develop the disease.
Immune System Dysregulation
Connective tissue diseases occur when the immune system becomes dysregulated and mistakenly targets the body’s own tissues. This can lead to persistent inflammation and, in some conditions, damage to affected tissues and organs.
Hormonal Factors
Many connective tissue diseases are more common in women, suggesting that sex hormones may influence immune responses and disease susceptibility. Hormonal influences appear to vary between different conditions, and their exact role in the development of connective tissue diseases is not fully understood.
Environmental Factors
Environmental factors may contribute to the development of autoimmune connective tissue diseases in people who are genetically susceptible. These may include certain infections, sunlight or ultraviolet (UV) exposure, smoking and other environmental exposures. However, the relevant factors vary between different connective tissue diseases, and their contribution to disease development is not fully understood.
Age
Connective tissue diseases can occur at any age, although many are commonly diagnosed during adolescence or adulthood. The typical age of onset varies considerably between different conditions.
When Should You See a Rheumatologist?
You may benefit from assessment by a rheumatologist if you have:
- Persistent joint pain, swelling or prolonged morning stiffness
- Persistent or unexplained fatigue
- Dry eyes or dry mouth, especially when associated with joint pain, fatigue or other symptoms
- Unexplained skin rashes, particularly those that appear after sun exposure
- Fingers or toes that change colour in response to cold temperatures (Raynaud's phenomenon)
- Persistent or unexplained muscle weakness
- Persistent or recurrent fevers or unexplained weight loss
These symptoms can have many different causes and do not necessarily indicate a connective tissue disease. However, when symptoms persist, are unexplained or occur together, a rheumatology assessment can help determine the underlying cause.
How Do Rheumatologists Diagnose Connective Tissue Diseases?
Diagnosing connective tissue diseases involves a careful assessment of your symptoms, medical history and examination findings, together with appropriate blood tests and specialised investigations.
Medical History and Symptom Assessment
A detailed medical history helps your rheumatologist understand the pattern and duration of your symptoms, identify affected organs, review your family history and look for features that may suggest an autoimmune connective tissue disease.
Physical Examination
Your rheumatologist will examine the joints, muscles, skin and other relevant organ systems for signs of inflammation or features associated with connective tissue disease.
Blood Tests
Blood tests may assess inflammation and organ function, as well as detect autoimmune antibodies such as antinuclear antibodies (ANA) and extractable nuclear antigen (ENA) antibodies. These antibodies are interpreted together with your symptoms and examination findings.
Imaging and Additional Investigations
Imaging such as ultrasound, X-rays, CT or MRI scans may be recommended depending on your symptoms. Additional investigations such as lung function tests, echocardiography, nailfold capillaroscopy or tissue biopsies may also be recommended when clinically indicated.
How Do Rheumatologists Treat Connective Tissue Diseases?
Treatment depends on the specific autoimmune connective tissue disease, its severity and the extent of organ involvement. The goals are to control inflammation, prevent or minimise organ damage, manage symptoms and maintain your quality of life.
Medications
Depending on the specific condition, symptoms and severity, treatment may include corticosteroids, disease-modifying anti-rheumatic drugs (DMARDs), biologic or targeted synthetic therapies. Additional treatments may be used to manage specific symptoms and to treat organ involvement where necessary.
Lifestyle Management
Healthy lifestyle measures can complement medical treatment and support overall wellbeing. These may include regular physical activity, adequate rest, smoking cessation,maintaining a balanced diet and sun protection where appropriate, particularly for conditions that are sensitive to ultraviolet exposure.
Ongoing Monitoring
Many connective tissue diseases require regular follow-up and monitoring to assess disease activity, response to treatment and potential organ involvement. Blood tests, imaging and other investigations may be performed when appropriate to guide treatment decisions and monitor for complications.
Multidisciplinary Care
Some people may benefit from coordinated care with other specialists, depending on the organs affected. This may include nephrologists, pulmonologists, dermatologists, ophthalmologists and other specialists working together with the rheumatologist to provide comprehensive care.
Dr Poh Yih Jia
Senior Consultant Rheumatologist
Dr Poh Yih Jia is a senior consultant rheumatologist with more than 20 years of medical experience in
New Zealand and Singapore. She has extensive experience in the diagnosis and management of connective
tissue diseases, inflammatory arthritis and other autoimmune rheumatic conditions affecting the joints,
muscles and internal organs.
Her commitment to patient-centred care has earned her multiple accolades, including the Singapore Health
Quality Service Award and the Service with a Heart Award. She remains dedicated to advancing
rheumatology through clinical practice, education and research, ensuring her patients receive the most
current, evidence-based care for autoimmune, inflammatory and musculoskeletal conditions.
FAQs on Connective Tissue Diseases
Many connective tissue diseases are autoimmune conditions in which the immune system becomes dysregulated and mistakenly targets the body’s own tissues. Examples include lupus, systemic sclerosis, Sjogren’s disease, inflammatory myositis and mixed connective tissue disease.
There is no single set of symptoms that applies to all connective tissue diseases. Symptoms vary depending on the specific condition and may include joint pain or swelling, fatigue, skin changes, dry eyes or mouth, muscle weakness and Raynaud's phenomenon. A rheumatologist can assess your symptoms and determine whether they may be related to an underlying autoimmune connective tissue disease.
Most autoimmune connective tissue diseases are chronic conditions that require ongoing management. While there is generally no permanent cure, modern treatments can help control inflammation, reduce disease activity and flares, and minimise the risk of long-term complications. Some people may experience prolonged periods of remission with appropriate treatment and monitoring.
Yes. Connective tissue diseases can affect different parts of the body beyond the joints. Depending on the specific condition, some people may develop involvement of the skin, lungs, kidneys, heart, blood vessels, muscles or nervous system. Not everyone with a connective tissue disease will develop organ involvement. Regular monitoring can help detect organ involvement early and guide treatment when needed.
Connective tissue diseases are generally not directly inherited. However, genetic factors can contribute to a person’s susceptibility to developing an autoimmune disease. Having a family history of an autoimmune or connective tissue disease may increase the likelihood of developing one, although it does not mean that the disease will necessarily be inherited.
Yes. Some connective tissue diseases can enter periods of remission or low disease activity with appropriate treatment. Regular monitoring is recommended to detect changes in disease activity and guide treatment when needed.