Progressive systemic sclerosis (PSS)


Also known as: PSS; Scleroderma (previously termed)
Last Review Date: January 13, 2020


What is PSS?

PSS is a group of connective tissue disorders with similar symptoms. They are associated with thickened, hardened skin, fibrosis, inflammation, blood vessel degeneration and tissue damage. PSS may be localised or systemic. It may be confined to patches of skin on the trunk, face, or extremities, or may affect large areas of the body, penetrating deep into muscle, bone, and internal organs such as the heart, lungs, gastrointestinal tract, and kidneys. Symptoms may range from cosmetic concerns to tissue damage and from pain and a decreased ability to move and use the hands to life-threatening kidney or lung dysfunction.

Localised sclerosis affects the skin and, in some cases, the muscle beneath it. There are two general types: morphea and linear scleroderma.

  • Morphea is associated with firm, thickened, discoloured oval patches of skin on the chest, back, legs, arms, or face. The patches may be reddened or white with a purplish border and may appear singly or cover large areas.
  • Linear scleroderma appears as a line or band of thickened tissue. If it forms over a child's joint, it may limit joint development and mobility.

Systemic sclerosis (SS) can be categorised as either limited SS or diffuse SS.

  • Limited SS typically affects specific areas of the body and may be referred to as "CREST," an acronym for the most common symptoms (see Signs & Symptoms).
  • Progressive SS is widespread. It can affect the skin and cause dysfunction in systems and organs throughout the body.

PSS is relatively rare and its prevalence is somewhat difficult to determine. It is estimated that there are about 240 cases for every million people, with about 19 new cases per million people each year. PSS is inflammatory and appears to have an autoimmune component, but the exact cause of the related disorders is not yet known. They can affect anyone at any age but most cases are seen in those who are between 20 and 40 years old. Women of child-bearing age are affected four times more often than men, so it is suspected that the disorders also have a hormonal component. Although a predisposition is not directly inherited, there are some increased frequencies of PSS tied to ethnicity. Localised SS is more common in those of European descent, while systemic sclerosis affects more women of African descent. PSS-like disorders are seen with exposures to chemicals such as vinyl chloride, trichloroethylene, and contaminated rapeseed oil, but SS itself has not been tied to an environmental trigger.


Signs and Symptoms

The signs and symptoms that someone experiences may range from mild to debilitating and in some cases can be life-threatening. They depend upon the type and severity of the PSS and will vary both from person to person and over time. Many of the symptoms may also be seen with other disorders and some are nonspecific. Nonspecific symptoms may include:

  • Joint pain
  • Difficulty swallowing
  • Fatigue
  • Dry mouth and mucus membranes
  • Loss of appetite

Localised sclerosis (morphea and linear scleroderma) 
People with localised sclerosis may have one or many patches or lines of thickened, hardened skin. The skin may be reddened or white with purplish borders. In some cases, large areas of the skin may have patterns of hypo- and hyper-pigmentation that give a salt-and-pepper effect.

Systemic sclerosis (LSS and PSS) 
People with limited SS commonly have one or more of the group of symptoms referred to as "CREST." These include:

  • Calcinosis: Small calcium deposits that develop under the skin, primarily on the fingers, knees and elbows. They can become infected and can cause painful, open sores when they break through the skin.
  • Raynaud's phenomenon: Blood vessels in the hands and feet contract in response to cold or emotional stress with this condition. When this happens, blood flow decreases and the affected fingers and toes turn white, then blue. When blood flow returns to normal, they turn red. The recurrent or prolonged interruption in blood flow can damage tissues, leading to sores and, in some severe cases, to gangrene and the need for amputation. Mild to moderate Raynaud's phenomenon is relatively common and only a small percentage of people who have Raynaud's also have PSS. On the other hand, up to 90 per cent of people with limited cutaneous PSS will have Raynaud's.
  • Esophageal dysfunction: Many people with PSS have difficulty swallowing due to muscle dysfunction in their oesophagus and may have acid reflux and chronic heartburn.
  • Sclerodactyly: This refers to the development of tight, thick skin on the fingers that makes them difficult to bend. There may be hair loss and the loss of sweat glands. The skin may be shiny and discoloured.
  • Telangiectasia: Associated with tiny red spots on the face and hands. It is caused by the swelling of small blood vessels.

The presence of a centromere pattern as seen on an ANA test by immunofluorescence is strongly associated with CREST. About 60-80 per cent of people with CREST will have this pattern. (See the section on Tests) Tests that are specific for centromere antibodies, available from certain reference laboratories, also will be positive in many of those with CREST.

When PSS occurs on the face, it may make the mouth opening narrower, making teeth cleaning and care more difficult.

Those with PSS may have skin and organ involvement. Organs that may be affected include:

  • Lungs: Fibrosis can stiffen lung tissue, making it harder to breath and leading to pulmonary hypertension. Lung dysfunction is the leading cause of death in systemic PSS.
  • Kidney: PSS can cause acute renal crisis that can be life-threatening. It can also cause hypertension and chronic renal dysfunction.
  • Heart: Less common, and more likely to occur after several years, heart involvement can lead to heart palpitations and congestive heart failure.

Complications associated with systemic sclerosis that may also be associated with other disorders include:

  • Carpal tunnel syndrome
  • Joint contractures
  • Muscle weakness
  • Constipation, diarrhoea, and malnutrition
  • Erectile dysfunction

Tests

The goals with testing for PSS include diagnosing the condition, distinguishing between different types, evaluating its severity and the degree of organ involvement, detecting complications, and monitoring the condition over time. The diagnosis is largely based upon clinical signs, with specific laboratory testing ordered to help confirm or rule out PSS and more routine or general testing used to help evaluate the person's health status. When the symptoms and test results are characteristic, diagnosing the condition may be relatively straightforward. In many cases, however, symptoms emerge slowly and can initially be mistaken for other conditions.

Laboratory tests

The primary tests performed to help diagnose PSS are autoantibodies. They include:

  • Antinuclear antibodies (ANA) – Positive with a variety of connective tissue and autoimmune disorders. Those with PSS typically have a speckled, nucleolar, or centromere pattern test result.
  • Scl-70 Antibody (Scleroderma Antibody, Anti-topoisomerase Antibody) – Positive in up to 60 per cent of those with PSS.
  • Centromere antibody/centromere pattern – Present in 60-80 per cent of people with limited cutaneous PSS and strongly associated with CREST.
  • RNA POLIII antibody associated with a nucleolar ANA and with renal involvement and disease  severity.

Rarely, a biopsy may be performed to evaluate fibrosis in affected tissue.

Routine testing to help monitor a person's general health status may include:

  • Full Blood Count (FBC) – to evaluate red and white blood cells
  • E/LFTs – to evaluate organ function and chemical and electrolyte balances
  • Nt-Pro BNP –  to screen for pulmonary hypertension
Non-laboratory tests
  • Lung function tests may be performed when lung involvement is suspected. 
  • CT (Computed Tomography) scans may be performed to evaluate lung damage. 
  • X-rays may be done to detect calcium deposits and evaluate lungs. 
  • Cardiac testing and monitoring may be performed when heart involvement is suspected.

Treatment

There is no cure for SS. In many cases, symptoms stabilise and begin to ease after several years. Skin may soften but remain discoloured and may become fragile. Tissue and organ damage that has accumulated is often permanent.

Treatment of SS is focused on managing symptoms, minimising damage to organs and tissues, and maintaining mobility in affected joints. Treatments may include:

For Raynaud's phenomenon:

  • Keeping hands and feet warm and avoiding temperature extremes
  • Avoiding smoking
  • In some cases, medications are used to help improve blood flow.

For Oesophageal dysfunction:

  • Small meals
  • Avoiding spicy foods
  • Proton pump inhibitors, antacids, H2-blockers and other medications

Other treatments may include:

  • Nonsteroidal anti-inflammatory drugs (NSAIDs) and other pain relievers
  • Topical skin treatments for open sores and for itching
  • Medications for hypertension and pulmonary hypertension
  • Supplemental oxygen
  • Corticosteroids and other immune suppressants
  • ACE inhibitors for acute kidney dysfunction
  • Physical and occupational therapy to maintain muscle strength and range of motion
  • Dental treatments
  • Autologous (a patient's own) Bone Marrow Transplant: This relatively new procedure is only available in certain centres for some patients with progressive severe disease.

Sometimes surgery is necessary to address tissue damage, joint contractures, or calcium deposits.


Related Pages

On this site
Tests: ANAENA PanelAutoantibodies
Conditions: Autoimmune Disorders

Elsewhere on the web
Scleroderma Australia
Better Health Channel
National Institute of Arthritis and Musculoskeletal and Skin Diseases: What Is Scleroderma? (USA)
Familydoctor.org: Scleroderma (USA)
Scleroderma Foundation (USA)