After reading this note you will be able to recognise the key clinical features of systemic sclerosis, order and interpret the essential investigations, grade disease severity and outline the immediate and definitive management plan (always verify drug choices, doses and local protocols against the Kenya MoH guideline and your hospital formulary).
Definition
Systemic sclerosis (SSc) is a chronic, multisystem autoimmune connective‑tissue disease characterised by progressive fibrosis of skin and internal organs, vasculopathy and immune dysregulation. It is classically divided into limited cutaneous (lcSSc) and diffuse cutaneous (dcSSc) subsets based on the extent of skin involvement.
Anatomy and physiology you need
| Structure | Relevance to SSc |
|---|---|
| Dermis & subcutaneous tissue | Target of fibroblast activation → skin thickening |
| Small arterioles & capillaries | Endothelial injury → Raynaud’s, digital ulcers |
| Lung interstitium & pulmonary vasculature | Fibrosis → interstitial lung disease (ILD); vasculopathy → pulmonary arterial hypertension (PAH) |
| Esophagus (smooth muscle) | Fibrosis → dysphagia, reflux |
| Kidneys (glomeruli & arterioles) | Vascular injury → scleroderma renal crisis |
| Heart (myocardium, pericardium, conduction system) | Fibrosis & vasospasm → arrhythmias, pericardial effusion |
| Gastro‑intestinal tract (stomach to colon) | Smooth‑muscle fibrosis → dysmotility, malabsorption |
Understanding that fibroblast activation, collagen over‑production and endothelial dysfunction are central helps link clinical signs to organ pathology.
Causes and risk factors
Genetic: HLA‑DRB111, DQA105, familial clustering.
Environmental: silica dust exposure (mining, construction), organic solvents (paint thinners).
Infections relevant to Kenya:
- HIV – chronic immune activation may precipitate auto‑immunity.
- Tuberculosis – molecular mimicry; co‑infection can mask early skin changes.
- Malaria – repeated inflammatory episodes may act as a trigger in genetically susceptible individuals.
- Sickle cell disease – vaso‑occlusive crises may exacerbate endothelial injury.
Other: Female sex (≈80 % of cases), age 30‑55, smoking, chronic stress.
Pathophysiology
Genetic susceptibility → environmental/infective trigger → immune activation → auto‑antibody production (e.g., anti‑centromere, anti‑Scl‑70) → endothelial injury → vasculopathy (intimal proliferation, luminal narrowing) → ischemia → fibroblast activation → excess collagen deposition → organ fibrosis.
Arrows format:
Genetic + Trigger → Immune activation → Auto‑antibodies → Endothelial injury → Vasculopathy → Ischemia → Fibroblast activation → Collagen over‑production → Skin & organ fibrosis.
Key mediators: TGF‑β, PDGF, endothelin‑1, IL‑6.
Clinical features
History – questions that matter
| Domain | Key questions | Rationale |
|---|---|---|
| Raynaud’s phenomenon | “Do your fingers or toes change colour when exposed to cold or stress? How long does each colour last?” | Early manifestation of digital vasospasm; helps differentiate primary from secondary Raynaud’s (the latter is common in systemic sclerosis). |
| Skin changes | “When did you first notice tightening of the skin? Which areas are affected? Any difficulty putting on clothes or opening jars?” | Progressive skin fibrosis begins on the fingers (sclerodactyly) and may spread proximally (limited vs diffuse). |
| Digital ulcers / pitting scars | “Do you have painful sores on the fingertips or tips? Have you noticed any scarring?” | Ulcers reflect severe microvascular disease; a marker of disease activity and risk of infection. |
| Gastro‑intestinal (GI) symptoms | “Do you have difficulty swallowing solids or liquids? Heartburn, reflux, bloating, constipation or diarrhoea?” | Esophageal dysmotility, gastro‑oesophageal reflux, intestinal hypomotility are common; early detection prevents complications. |
| Respiratory complaints | “Do you have shortness of breath on exertion or at rest? Any dry cough?” | Interstitial lung disease (ILD) and pulmonary arterial hypertension (PAH) are leading causes of mortality. |
| Cardiovascular symptoms | “Chest pain, palpitations, syncope, swelling of ankles?” | Myocardial fibrosis, pericardial effusion, PAH can present with these signs. |
| Renal involvement | “Any recent swelling of legs, reduced urine output, blood in urine, sudden rise in blood pressure?” | Scleroderma renal crisis (SRC) is an emergency; early hypertension or proteinuria is a red flag. |
| Musculoskeletal | “Joint pain, stiffness, swelling? Muscle weakness?” | Polyarthritis, myopathy may coexist; helps differentiate from other rheumatic diseases. |
| Systemic symptoms | “Fever, weight loss, fatigue?” | Non‑specific but may indicate active disease or infection (important in our setting with TB, HIV). |
| Exposure / comorbidities | “Do you have HIV, TB, malaria, sickle cell disease? Any recent infections or vaccinations?” | In Kenya, co‑existing infections can modify presentation and influence drug choice (e.g., avoid high‑dose steroids in active TB). |
| Family history | “Any relatives with autoimmune disease?” | Genetic predisposition; may raise suspicion for overlap syndromes. |
| Medication history | “Use of calcium channel blockers, ACE inhibitors, NSAIDs, immunosuppressants?” | Baseline therapy may mask or modify symptoms; important for drug interactions. |
Examination – findings and why they occur
| Finding | Pathophysiologic basis |
|---|---|
| Sclerodactyly – thickened, taut skin of fingers, loss of skin creases | Collagen over‑production in dermis causing fibrosis; limits joint flexion. |
| Digital pitting scars / ulcers | Chronic ischemia from obliterative vasculopathy of digital arterioles. |
| Facial skin tightening – “mask‑like” appearance, reduced nasolabial folds | Diffuse dermal fibrosis extending to face. |
| Telangiectasia – blanch‑red spots on face, hands, oral mucosa | Dilated post‑capillary venules secondary to endothelial injury. |
| Calcinosis cutis – firm subcutaneous nodules, may ulcerate | Calcium deposition in areas of chronic inflammation and tissue hypoxia. |
| Raynaud’s colour change – triphasic (white‑blue‑red) on cold exposure | Exaggerated sympathetic vasoconstriction of digital arteries. |
| Reduced chest expansion – “shiny” skin over thorax, decreased inspiratory depth | Skin and sub‑cutaneous fibrosis restrict rib cage movement, predisposing to restrictive lung pattern. |
| Bibasilar crackles | Interstitial fibrosis of lung parenchyma. |
| Elevated JVP, right‑sided heart sounds | Pulmonary arterial hypertension leading to right‑heart strain. |
| Peripheral edema, hypertension | Early renal involvement (SRC) or cardiac failure. |
| Joint contractures | Fibrosis of peri‑articular tissues limiting range of motion. |
| Abdominal tenderness / ascites | Mesenteric vascular involvement or portal hypertension secondary to liver fibrosis (rare). |
Differential diagnosis
| Condition | Points toward it | What separates it from systemic sclerosis |
|---|---|---|
| Systemic lupus erythematosus | Positive ANA, malar rash, photosensitivity, renal nephritis | Lack of widespread skin thickening; presence of anti‑dsDNA, low complement; lupus rash is distinct. |
| Dermatomyositis | Gottron papules, heliotrope rash, proximal muscle weakness | Prominent muscle inflammation, CK elevation; skin changes are inflammatory not fibrotic. |
| Mixed connective tissue disease | Overlap of SLE, polymyositis, scleroderma features; high anti‑U1 RNP | Prominent myositis and Raynaud’s but skin fibrosis less extensive; serology differs. |
| Eosinophilic fasciitis | Rapid onset of painful swelling of forearms, “groove sign”, eosinophilia | No Raynaud’s, no internal organ involvement; skin thickening limited to fascia. |
| Scleroderma‑like drug reaction (e.g., bleomycin) | Temporal relation to offending drug, reversible | History of drug exposure; improvement after withdrawal. |
| Localized scleroderma (morphea) | Plaque‑like indurated lesions, no systemic features | Confined to skin, no Raynaud’s, no internal organ disease. |
| Raynaud’s disease (primary) | Isolated colour change, normal nailfold capillaries | Absence of skin thickening, ulcers, or internal organ involvement. |
Investigations
| Test | What it answers | Interpretation |
|---|---|---|
| ANA (screen) | Presence of auto‑antibodies | Positive in >90 % of patients; non‑specific. |
| Anti‑centromere antibody | Limited cutaneous disease (CREST) | Positive → limited form, lower ILD risk. |
| Anti‑Scl‑70 (topoisomerase I) | Diffuse cutaneous disease | Positive → higher ILD and renal risk. |
| Anti‑RNA polymerase III | Rapid skin thickening, renal crisis | Positive → strong predictor of SRC. |
| Nailfold capillaroscopy | Microvascular damage | Giant capillaries, avascular areas support diagnosis; helps differentiate primary Raynaud’s. |
| Pulmonary function tests (spirometry + DLCO) | Lung involvement severity | Reduced FVC and DLCO indicate ILD; isolated DLCO drop suggests PAH. |
| High‑resolution CT chest | Extent of interstitial fibrosis | Ground‑glass opacities, honey‑comb pattern confirm ILD. |
| Echocardiography (transthoracic) | Pulmonary arterial pressure, cardiac function | Elevated PASP → PAH; pericardial effusion or LV dysfunction noted. |
| Renal function panel (creatinine, electrolytes, urinalysis) | Detect renal crisis | Rising creatinine, new proteinuria, or hypertension signals SRC. |
| Complete blood count | Anemia, leukopenia, thrombocytopenia | May reflect chronic disease or drug toxicity. |
| CRP/ESR | Inflammatory activity | Elevated in active disease or superimposed infection. |
| Serum creatine kinase | Myositis component | Raised if overlap with polymyositis. |
| Chest X‑ray | Baseline lung status | May show ILD or pulmonary hypertension signs. |
Diagnosis and severity
Diagnostic criteria (adapted for our setting)
- Skin thickening of the fingers extending proximal to the metacarpophalangeal joints (mandatory).
- Raynaud’s phenomenon (clinical or capillaroscopic evidence).
- Scleroderma‑specific antibodies (anti‑centromere, anti‑Scl‑70, anti‑RNA polymerase III).
- Internal organ involvement (ILD, PAH, renal, GI, cardiac).
Definite systemic sclerosis = skin thickening + Raynaud’s + ≥ one of the above (auto‑antibody or organ involvement).
Severity grading (practical for clinical rotations)
| Domain | Mild | Moderate | Severe |
|---|---|---|---|
| Skin | Limited to distal digits (≤ 10 % BSA) | Extends to forearms or calves | Diffuse, trunk involvement (> 30 % BSA) |
| Lung | Normal PFT, HRCT | FVC 50‑70 % predicted, DLCO 40‑60 % | FVC < 50 %, progressive fibrosis, PAH (PASP > 50 mmHg) |
| Renal | Normal creatinine, BP | Mild hypertension, proteinuria | Sudden rise in BP, creatinine > 150 µmol/L (SRC) |
| GI | Mild dysphagia, occasional reflux | Frequent reflux, early dysphagia, malabsorption | Severe dysphagia, pseudo‑obstruction, weight loss |
| Cardiac | No echo abnormalities | Mild pericardial effusion, diastolic dysfunction | PAH, systolic dysfunction, arrhythmias |
| Functional | Able to perform daily activities | Limited ADL, needs assistance | Bed‑bound or requires full support |
Severity guides therapy: Mild disease may be managed with symptomatic agents (e.g., calcium‑channel blockers for Raynaud’s, proton‑pump inhibitors for reflux). Moderate–severe disease warrants early introduction of disease‑modifying agents (mycophenolate mofetil, cyclophosphamide, or newer antifibrotics) and close monitoring for organ complications.
Prepared for Year‑4 MBChB clinical rotations – Kenya.
Management
Immediate stabilisation
- Airway‑breathing‑circulation: give supplemental O₂ if SpO₂ < 94 % or signs of pulmonary hypertension/ILD exacerbation.
- Fluid balance: avoid aggressive IV fluids in patients with severe Raynaud‑related digital ischemia or pulmonary hypertension; give judicious crystalloid bolus only if hypotensive.
- Pain & ulcer care: treat digital ulcers with local wound care, protect with non‑adhesive dressings, and start a vasodilator (e.g., calcium‑channel blocker) promptly.
- Renal crisis: monitor blood pressure every 15 min; if malignant hypertension develops, initiate ACE‑inhibitor therapy emergently and arrange ICU transfer.
Definitive (long‑term) treatment
| Manifestation | First‑line class | Typical agents (no doses) | Rationale |
|---|---|---|---|
| Skin fibrosis & early disease | Disease‑modifying anti‑fibrotics | Mycophenolate mofetil, cyclophosphamide (IV) | Reduce collagen deposition, improve skin scores |
| Interstitial lung disease (ILD) | Anti‑fibrotics / immunosuppressants | Nintedanib, pirfenidone, mycophenolate | Slow FVC decline, limit progression |
| Pulmonary arterial hypertension (PAH) | Targeted PAH therapy | Endothelin‑receptor antagonist, phosphodiesterase‑5 inhibitor, prostacyclin analogue (inhaled/IV) | Vasodilation, improve RV function |
| Raynaud’s & digital ulcers | Vasodilators | Calcium‑channel blocker, phosphodiesterase‑5 inhibitor, prostacyclin analogue (topical) | Improves microvascular flow |
| Scleroderma renal crisis | ACE‑inhibitor (e.g., captopril) | – | Rapid BP control, renal protection |
| Gastro‑intestinal dysmotility | Pro‑kinetics | Metoclopramide, domperidone | Improves esophageal clearance |
| Musculoskeletal pain | NSAID (short course) or low‑dose glucocorticoid | – | Symptom control; avoid long‑term steroids due to infection risk |
Monitoring & follow‑up
- Every 3–6 months: modified Rodnan skin score, pulmonary function tests (FVC, DLCO), echocardiogram, renal function, BP.
- Every 12 months: high‑resolution CT chest if ILD progression suspected; right‑heart catheterisation if PAH worsens.
- Safety checks: CBC and liver enzymes for mycophenolate/cyclophosphamide; renal function and electrolytes for ACE‑inhibitors; screen for infections (TB, hepatitis) before immunosuppression.
Contra‑indications / safety
- ACE‑inhibitors contraindicated in pregnancy.
- Cyclophosphamide avoided in severe cytopenia or active infection.
- Nintedanib/pirfenidone require baseline liver tests; stop if transaminases > 3 × ULN.
- Calcium‑channel blockers should be used cautiously in severe left‑ventricular dysfunction.
Complications and prognosis
| Complication | Clinical impact | Key monitoring |
|---|---|---|
| Interstitial lung disease | Leading cause of mortality; progressive dyspnoea, hypoxia | Serial PFTs, HRCT, O₂ sat |
| Pulmonary arterial hypertension | Right‑heart failure, reduced survival | Echo, NT‑proBNP, 6‑min walk |
| Scleroderma renal crisis | Acute renal failure, malignant hypertension | Daily BP, renal panel |
| Digital ulcers / gangrene | Pain, infection, possible amputation | Wound inspection, Doppler if ischemic |
| Gastro‑intestinal dysmotility | Malnutrition, aspiration | Barium swallow, nutritional labs |
| Cardiac arrhythmias / myocarditis | Sudden death risk | ECG, Holter, cardiac MRI if symptomatic |
| Malignancy (especially lung) | Higher incidence in diffuse disease | Age‑appropriate cancer screening |
Prognosis hinges on extent of internal organ involvement. Early detection of ILD or PAH markedly improves survival; skin‑limited disease generally has a more favourable course.
High‑yield exam points
- Look‑alike conditions:
- CREST vs. mixed connective tissue disease (presence of anti‑U1 RNP, more prominent myositis).
- Systemic lupus erythematosus with Raynaud’s (anti‑dsDNA, low complement).
- Commonest wrong first step: Starting high‑dose steroids for skin fibrosis without confirming absence of infection or renal crisis; steroids can precipitate renal crisis.
- Bedside examiner questions:
- “Explain why you would avoid high‑dose prednisolone in this patient.”
- “What is the significance of a reduced DLCO in systemic sclerosis?”
- “How does the modified Rodnan skin score guide management?”
- Key exam facts:
- Anti‑centromere antibodies → limited cutaneous disease, better prognosis.
- Anti‑Scl‑70 (topoisomerase I) → diffuse disease, higher ILD risk.
- Malignant hypertension + new‑onset renal failure = scleroderma renal crisis → ACE‑inhibitor emergently.
Clinical case
Case: 42‑year‑old Kenyan woman, teacher, presents with 8‑month history of tightening skin over hands and face, recent dyspnoea on exertion, and painful ulcer on the tip of the right index finger. Examination shows sclerodactyly, telangiectasia on the face, reduced breath sounds at bases, and a blood pressure of 165/105 mmHg. Labs reveal anti‑Scl‑70 positivity; HRCT shows ground‑glass changes involving 20 % of lung fields.
Questions
- What is the most urgent complication to exclude?
Answer: Scleroderma renal crisis – because of newly elevated BP and risk of rapid renal decline.
- Which long‑term therapy addresses both her skin disease and early interstitial lung disease?
Answer: Mycophenolate mofetil – it moderates fibrosis and is effective for ILD.
- What bedside maneuver helps assess the severity of Raynaud’s‑related digital ischemia?
Answer: Perform a cold‑challenge test and observe for colour change; Doppler ultrasound can quantify arterial flow if ulceration is present.
Practice questions
Question 1
A 55‑year‑old man with diffuse systemic sclerosis presents with sudden onset of headache, visual disturbances, and BP 190/120 mmHg. Urine shows proteinuria. What is the next best step?
A. Start high‑dose oral prednisolone
B. Initiate intravenous ACE‑inhibitor
C. Give intravenous methylprednisolone
D. Order renal biopsy
Answer: B. Initiate intravenous ACE‑inhibitor
Explanation: This picture is classic for scleroderma renal crisis; ACE‑inhibitors are the treatment of choice and should be started immediately.
Question 2
A patient with limited cutaneous systemic sclerosis complains of increasing dyspnoea. PFT shows FVC 55 % predicted, DLCO 45 % predicted. HRCT reveals early basal fibrosis. Which medication class is most appropriate to slow lung disease progression?
A. Calcium‑channel blockers
B. Anti‑fibrotic agents
C. Long‑acting β‑agonists
D. High‑dose NSAIDs
Answer: B. Anti‑fibrotic agents
Explanation: Nintedanib or pirfenidone are indicated for progressive ILD in systemic sclerosis to reduce FVC decline.
Question 3
A 30‑year‑old woman with CREST syndrome has severe Raynaud’s causing digital ulceration. Which therapy is contraindicated?
A. Topical nitroglycerin paste
B. Intravenous prostacyclin analogue
C. High‑dose oral corticosteroids
D. Oral phosphodiesterase‑5 inhibitor
Answer: C. High‑dose oral corticosteroids
Explanation: Large steroid doses increase the risk of renal crisis in systemic sclerosis and are not indicated for isolated Raynaud’s.
Question 4
During a routine review, a patient with systemic sclerosis reports new dysphagia to solids and liquids. Which investigation should be performed first?
A. Barium swallow study
B. Upper GI endoscopy with biopsy
C. Esophageal manometry
D. 24‑hour pH monitoring
Answer: A. Barium swallow study
Explanation: It quickly identifies esophageal dysmotility and strictures, guiding further management; endoscopy is reserved for suspicion of ulceration or malignancy.
Question 5
A patient with diffuse systemic sclerosis is started on mycophenolate mofetil. Which monitoring parameter is most essential in the first three months?
A. Serum calcium
B. Liver transaminases
C. Serum uric acid
D. Serum ferritin
Answer: B. Liver transaminases
Explanation: Mycophenolate can cause hepatotoxicity; regular LFTs are required to detect early injury.
Drafted with AI assistance from standard references and reviewed for structure. Check details against your lecture notes and the Kenya MoH guideline.