Scleroderma

Scleroderma is a group of autoimmune diseases characterised by abnormal growth of connective tissue, leading to changes in the skin, blood vessels, muscles, and internal organs. The disease can be localised to the skin or systemic, affecting various organs.

The precise cause remains unknown, but it involves an abnormal immune response with risk factors including family history, certain genetic factors, and exposure to silica.

Signs and Symptoms

Scleroderma symptoms vary but commonly include skin thickening, stiffness, fatigue, and poor blood flow to extremities, particularly with cold exposure. Systemic scleroderma can involve multiple organ systems:

• Cardiovascular: Raynaud's phenomenon, skin and mucosal telangiectasis, hypertension, and heart complications.
• Digestive: Gastroesophageal reflux disease (GERD), bloating, diarrhoea, constipation, and hoarseness.
• Pulmonary: Shortness of breath, chest pain, and a persistent cough.
• Musculoskeletal: Joint and muscle pain, loss of motion, and muscle weakness.
• Genitourinary: Erectile dysfunction, dyspareunia, kidney issues, or failure.
• Other: Facial pain, hand paresthesias, headache, fatigue, calcinosis, and weight loss.

Diagnosis

Diagnosis is based on clinical symptoms, supported by skin biopsy or blood tests. Typical features include symmetrical skin thickening, Raynaud's phenomenon, nail-fold capillary changes, and the presence of antinuclear antibodies.

Laboratory tests may detect antitopoisomerase (anti-Scl70) or anticentromere antibodies, which help distinguish between diffuse and limited systemic forms.

Differential diagnoses include eosinophilia-myalgia syndrome, eosinophilic fasciitis, graft-versus-host disease, and nephrogenic systemic fibrosis.

Pathophysiology

The disease involves increased collagen synthesis, damage to small blood vessels, T lymphocyte activation, and altered connective tissue production. The inciting event, possibly viral or autoimmune, damages endothelial cells, leading to vascular leakiness, impaired angiogenesis, and fibrosis due to fibroblast activation by cytokines like TGF-β.

Vitamin D deficiency may also play a role.

Treatment

There is no cure, but treatment aims to relieve symptoms:

• Raynaud's Phenomenon: Vasodilators such as calcium channel blockers and local nitrates.
• Digital Ulcers: Phosphodiesterase inhibitors and iloprost.
• Pulmonary Issues: Cyclophosphamide, azathioprine, endothelin receptor antagonists, and prostanoids.
• Gastroesophageal Reflux Disease (GERD): Antacids or prokinetics.
• Kidney Crisis: ACE inhibitors and angiotensin II receptor antagonists.

Systemic immunosuppressive therapy includes azathioprine, methotrexate, mycophenolate, and biologics like rituximab. Experimental therapies involve tyrosine kinase inhibitors and haematopoietic stem cell transplantation.

Prognosis

Prognosis varies with disease type. Localised scleroderma generally does not affect life expectancy, while systemic forms, particularly diffuse systemic sclerosis, have a worse prognosis.

Pulmonary hypertension, fibrosis, and renal crisis are major causes of death. The five-year survival rate for systemic scleroderma is about 85%, and the 10-year survival rate is just under 70%.

Epidemiology

Scleroderma typically presents between ages 20 and 50, with a higher prevalence in women. In the U.S., the prevalence is estimated at 240 per million, with an annual incidence of 19 per million.

It is more common in African Americans and certain Native American tribes, such as the Choctaw. Global prevalence varies, with estimates of 10 to 150 per million people.

Pregnancy

Scleroderma complicates pregnancy, increasing risks to both mother and foetus. Careful management is required to avoid teratogenic medications, with alternatives like hydroxychloroquine and low-dose corticosteroids for disease control.

---

Self-assessment MCQs (single best answer)

Which of the following is a characteristic symptom of systemic scleroderma?

What is the primary method of diagnosing scleroderma?

Which of the following is NOT a common treatment for scleroderma?

Which subtype of scleroderma is associated with a worse prognosis due to more extensive internal organ involvement?

Raynaud's phenomenon in scleroderma patients is best described as:

Which antibody is commonly associated with diffuse systemic scleroderma?

Which organ is NOT typically affected by systemic scleroderma?

What is the primary risk factor for developing scleroderma?

Which of the following is a major complication associated with systemic scleroderma?

Which of the following is a known environmental risk factor for scleroderma?