This blog post summarises the key insights from the latest Virtual Education Session (VES) presented by Professor Susanna Proudman, director of the rheumatology unit at the Royal Adelaide Hospital. As an ARA Michael Mason Fellow, she trained and established one of the first Early Arthritis Clinics in the world. She has been working in scleroderma research for decades, establishing the Australian Scleroderma Cohort Study in 2007 with collaborations such as the International Systemic Sclerosis Inception Cohort (INSYNC) and the Scleroderma Clinical Trials Consortium Damage Index working group. 

For more free resources, access our in-depth and targeted information brochures here.

The latest virtual education session hosted by Professor Susanna Proudman focused on lesser-discussed aspects of scleroderma, particularly gastrointestinal and muscle involvement. While much of the focus in scleroderma research and treatment remains on more prominent complications like interstitial lung disease and renal crisis, certain areas – such as muscle disease – are often overlooked. Recent work led by Dr Laura Ross and PhD student Jess Fairley at St Vincent’s Hospital, Melbourne, is helping to address this gap.

Scleroderma leads to skin thickening and internal organ involvement. It typically presents in two subtypes: diffuse and limited cutaneous scleroderma, each with distinct clinical trajectories. Diffuse scleroderma tends to progress rapidly and is more likely to affect organs early, while limited scleroderma progresses more slowly.

At the core of scleroderma are three key pathological processes:

  • Inflammation and autoimmunity, triggered by genetic and environmental factors
  • Vasculopathy, seen in conditions like Raynaud’s phenomenon and digital ulcers
  • Fibrosis, or the excessive build-up of collagen in the skin, lungs, and muscles

Muscle is a vital organ system – impacting mobility, organ function, metabolism, and quality of life. Muscle types discussed included:

  • Skeletal muscle (voluntary movement)
  • Cardiac muscle (heart function)
  • Smooth muscle (involuntary organ movements like digestion and breathing)

While skin thickening and internal organ complications like lung and kidney disease are more familiar hallmarks of scleroderma, Professor Proudman explained that muscle disease can significantly contribute to weakness, pain, and reduced quality of life. In rare but important cases, it may even be linked with serious cardiovascular issues, including an increased – though still very low – risk of sudden cardiac death.

Types of Muscle Involvement in Scleroderma

Skeletal muscle involvement in scleroderma exists on a spectrum:

  • At one end is the inflammatory myopathy, most clearly seen in overlap cases with polymyositis. These cases are relatively well understood and can be diagnosed and treated similarly to polymyositis alone.
  • At the other end is non-inflammatory fibrosis, where muscle damage occurs without clear signs of inflammation – possibly due to chronic vasculopathy or subclinical inflammation. This type is less understood and may affect most people with scleroderma to some degree, even if not clinically obvious.

Symptoms and Clinical Presentation

Muscle involvement typically affects the proximal muscle groups – such as those around the shoulders, hips, and thighs – and is often bilateral. Symptoms include:

  • Muscle weakness and fatigue
  • Difficulty climbing stairs, rising from chairs, or lifting objects
  • Neck weakness
  • Swallowing difficulties (especially if the oesophageal or pharyngeal muscles are affected)
  • Breathing issues, particularly in those with pre-existing interstitial lung disease
  • Occasional cardiac muscle involvement, potentially causing conduction issues

A notable sign is Gowers’ sign, where a patient uses their hands to push themselves up from a seated position.

Diagnosis and Testing

Diagnosing muscle involvement involves a combination of clinical assessment and diagnostic testing, including:

  • Creatine kinase (CK) blood levels – Often elevated in myositis but can be normal even with muscle disease
  • Autoantibody panels – Myositis-specific antibodies such as anti-Jo-1 and anti-SRP may be present in some overlap cases
  • MRI imaging – Used to visualise inflammation or fibrosis within muscle tissue, though interpretation requires specialist expertise
  • Electromyography (EMG) – Measures electrical activity in muscle, though rarely used due to long wait times and invasive nature
  • Muscle biopsy – Occasionally performed for definitive diagnosis
  • Lung function tests and CT scans – Helpful in distinguishing between respiratory issues caused by muscle weakness vs interstitial lung disease

Diagnosing Muscle Disease: MRI and Biopsy

MRI scans play a key role in identifying areas of muscle inflammation, appearing as bright white regions on fat-saturated images. These scans guide clinicians to precisely target muscle biopsies – considered the gold standard for diagnosis.

A muscle biopsy can confirm whether muscle symptoms are caused by inflammatory myositis or non-inflammatory fibrosis/atrophy. This distinction is crucial:

  • Inflammation = potential for immunosuppressive treatment
  • No inflammation = avoid unnecessary medication risks

However, biopsies are invasive procedures often requiring general anaesthesia and carry risks, so they are not undertaken lightly. Even with MRI guidance, up to 1 in 8 biopsies may appear normal despite ongoing disease.

Who Gets Screened?

Muscle involvement is under-recognised. While overlap myositis is usually picked up, many patients may have subclinical or non-inflammatory changes contributing to weakness and disability.

ASIC has developed a screening algorithm, incorporating:

  • Annual CK blood testing
  • Muscle strength assessments
  • Symptom tracking (e.g. difficulty climbing stairs or rising from a chair)

This helps identify patients who may need further testing such as MRI, autoantibody screening, or ultimately, a biopsy.

How Common Is It?

Estimates vary dramatically – from 6% to 96% – due to differing definitions. But in the Australian Scleroderma Cohort, biopsy-confirmed myositis appears in 2–10% of patients. Importantly, some had normal CK levels, reinforcing the need for careful clinical assessment.

Causes Beyond Myositis

Not all muscle weakness is caused by inflammation, other reasons include:

  • Deconditioning due to inactivity
  • Malnutrition, especially due to malabsorption
  • Medication side effects (e.g. statins, steroids)
  • Tight skin/joint contractures in scleroderma

All reasons can play a role, and it’s vital to consider these in assessments.

Treatment Approaches

For inflammatory myositis, treatment might include:

  • Corticosteroids (e.g. prednisolone) – used cautiously due to risk of scleroderma renal crisis, especially in those with RNA polymerase III antibodies
  • Immunosuppressants – e.g. mycophenolate, azathioprine
  • IVIG (intravenous immunoglobulin) – effective and may help skin disease too
  • Biologic agents – such as rituximab

Importantly, treatment is only used when inflammation is confirmed, to avoid unnecessary risk.

The Power of Exercise

Perhaps the most encouraging message of the session was this: Exercise is medicine.

Even when inflammation is present, exercise:

  • Stimulates muscle fibre regeneration
  • Counters atrophy
  • Has anti-inflammatory effects
  • Improves cardiopulmonary fitness and endurance

Resistance training, in particular, is safe and effective, even in people with autoimmune muscle disease.

Studies from Adelaide and Victoria (e.g. Dr Laura Ross’s work) show that people with scleroderma have reduced exercise capacity compared to healthy controls, likely due to a combination of muscle and cardiac fibrosis. However, targeted exercise programs have been shown to slow decline and improve strength and quality of life.

While inflammation damages tissue, movement preserves and enhances it. For those living with scleroderma, the key is:

  • Stay active, even if progress is slow
  • Work with experts who understand your condition
  • Advocate for more than five allied health visits if needed
  • Don’t accept decline as inevitable

Supporting Muscle Health Holistically

Muscle care in scleroderma doesn’t stop at medication:

  • Physiotherapy and rehabilitation are vital
  • Nutrition support to address deficiencies and malabsorption
  • Preventative care – e.g. osteoporosis management, vaccinations, and cancer screening
  • Assistive aids and NDIS support, where needed

The Heart Muscle: Understanding Cardiac Involvement

Cardiac muscle – or myocardium – differs significantly from skeletal muscle. Its branched structure enables strong, coordinated contractions to pump blood efficiently. In scleroderma, the heart can be affected both directly and indirectly:

Direct effects:

  •  Inflammation and fibrosis of the heart muscle
  •  Vasculopathy (narrowing of blood vessels) affecting blood supply to the heart
  •  Myocarditis (inflammation of the myocardium)
  •  Pericarditis (inflammation of the outer lining of the heart)

Indirect effects:

  •  Secondary strain from lung disease (like pulmonary arterial hypertension or interstitial lung disease)
  •  Cardiac changes due to renal disease

These changes can lead to:

  • Arrhythmias (irregular heartbeat)
  • Myocardial infarction (heart muscle damage due to poor circulation)
  • Heart failure, often due to muscle weakening or scarring

Diagnosing and Treating Heart Involvement

Symptoms of heart involvement may include:

  • Fatigue
  • Shortness of breath
  • Swelling of ankles
  • Palpitations
  • Neck vein distension

Diagnosis tools include:

  • ECG for rhythm abnormalities
  • Echocardiogram (ultrasound of the heart)
  • Cardiac MRI to detect inflammation or fibrosis
  • Occasionally, an endomyocardial biopsy

If inflammation is present, immunosuppressive treatment may be escalated (e.g. adding rituximab). Heart failure is treated conventionally with:

  • Oxygen therapy
  • Fluid restriction
  • ACE inhibitors and beta-blockers

Heart transplant is rare, though very occasionally patients with severe lung and heart disease may be considered for heart-lung transplantation.

How Common Is Cardiac Muscle Involvement?

Cardiac muscle disease affects roughly 1 in 40 people with scleroderma. While serious muscle disease involving the skeletal or cardiac muscle is relatively uncommon (less than 10%), it can have a significant impact on function and survival. Early recognition and proactive management are essential.

Takeaway: The Power of Awareness and Activity

In closing, it was emphasised:

  • Heart and skeletal muscle involvement are underdiagnosed in scleroderma
  • Fatigue and pain can stem from many sources – not just inflammation
  • Physical activity, even at a reduced capacity, is essential for long-term health and strength
  • Early intervention and multidisciplinary care can help manage muscle and heart complications effectively

For those living with Scleroderma, staying updated and informed can make a world of difference. Connecting with others can also be hugely beneficial. Find out more about support in your area here. 

If you’d like to gain firsthand knowledge, our National Education Sessions and Virtual Education Sessions are available to you at no charge. Our Virtual Education Sessions are held every month through Google Meet. You can sign up for these free Virtual Education Sessions here.

These sessions provide an opportunity to engage with medical professionals and seasoned legal experts who will address common inquiries about Scleroderma and related topics.