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4 Common Rheumatologic Conditions You Need to Know About

Updated: Jan 23

Rheumatology diseases are diverse diseases that primarily affect the joints, muscles, and connective tissues. Let's delve into the common rheumatological diseases you've mentioned: Rheumatoid Arthritis, Systemic Lupus Erythematosus (SLE), Scleroderma, and Myositis.

  • Pathophysiology: RA is a chronic autoimmune disorder characterized by synovial inflammation and joint destruction. The body's immune system mistakenly attacks its own tissues, especially the synovium, the lining of the membranes that surround the joints.

  • Clinical Features: Symptoms include tender, warm, swollen joints, morning stiffness that lasts for hours, and rheumatoid nodules. It commonly affects joints symmetrically.

  • Diagnosis: RA is diagnosed based on clinical presentation, elevated inflammatory markers (ESR, CRP), and the presence of antibodies like Rheumatoid Factor (RF) and Anti-Citrullinated Protein Antibody (ACPA).

  • Management: Treatment involves DMARDs (Disease Modifying Anti-Rheumatic Drugs) like methotrexate, biological agents, physical therapy, and sometimes surgery for joint repair.

  • Pathophysiology: SLE is an autoimmune disease where the immune system attacks its own tissues, causing widespread inflammation and tissue damage in the affected organs.

  • Clinical Features: It can affect the skin, joints, kidneys, brain, and other organs. Common symptoms include fatigue, joint pain, rash (notably the butterfly rash on the face), and fever.

  • Diagnosis: Diagnosis is based on a combination of clinical findings and laboratory tests, including ANA (Antinuclear Antibody), anti-dsDNA, and anti-Smith antibodies.

  • Management: There is no cure for SLE, but treatments like corticosteroids, hydroxychloroquine, and immunosuppressants can help control symptoms.

  • Pathophysiology: Scleroderma involves abnormal growth of connective tissue, causing skin tightening and thickening. It can also affect internal organs.

  • Clinical Features: Symptoms vary but can include hardening and tightening of the skin, Raynaud’s phenomenon, gastroesophageal reflux disease (GERD), and difficulty swallowing.

  • Diagnosis: Diagnosed through clinical evaluation, skin biopsy, and blood tests showing antibodies such as anti-Scl-70 and anti-centromere antibodies.

  • Management: Treatment focuses on managing symptoms and may include drugs to improve blood flow, reduce stomach acid, and suppress the immune system.

  • Pathophysiology: Myositis is an inflammation of the muscles, often due to an autoimmune response.

  • Clinical Features: Common symptoms include muscle weakness, swelling, pain, and fatigue. It can affect both the skin and muscles (dermatomyositis) or just the muscles (polymyositis).

  • Diagnosis: Diagnosed through clinical assessment, elevated muscle enzymes in the blood (like creatine kinase), electromyography, and muscle biopsy.

  • Management: Treatment includes corticosteroids and immunosuppressive drugs. Physical therapy is also an important part of the management to maintain muscle strength and flexibility.

2010 Rheumatoid Arthritis Classification Criteria (Developed by the American College of Rheumatology (ACR) and the European League Against Rheumatism (EULAR)):

Joint Involvement:

  • Single large joint (0 points)

  • 2–10 large joints (1 point)

  • 1–3 small joints (with or without involvement of large joints) (2 points)

  • 4–10 small joints (with or without involvement of large joints) (3 points)

  • 10 joints (at least 1 small joint) (5 points)

Serology (at least one test result is needed for classification):

  • Negative RF and negative ACPA (0 points)

  • Low-positive RF or low-positive ACPA (2 points)

  • High-positive RF or high-positive ACPA (3 points)

Acute-Phase Reactants (at least one test result is needed for classification):

  • Normal CRP and normal ESR (0 points)

  • Abnormal CRP or abnormal ESR (1 point)

Duration of Symptoms:

  • <6 weeks (0 points)

  • ≥6 weeks (1 point)

Patients with a score of 6 or more out of 10 are classified as having definite RA.

Clinical Approach for Medical Students: When learning these criteria, it's important to remember that RA is a clinical diagnosis and these criteria are primarily used for classification in research contexts. However, they are also helpful in guiding diagnosis.

To remember these criteria, you can focus on the pattern of joint involvement, the presence and levels of specific antibodies (RF and ACPA), the systemic inflammation reflected by CRP and ESR, and the duration of symptoms. The scoring helps quantify the likelihood of RA, with a higher score indicating a greater probability of the disease.

Systemic Lupus Erythematosus (SLE), The updated ACR (American College of Rheumatology) and EULAR (European League Against Rheumatism) criteria for the classification of Systemic Lupus Erythematosus (SLE). These criteria are used to standardize the diagnosis of SLE for clinical studies and can also guide clinicians in practice. Let's break down the criteria:

Clinical Domains and Immunologic Domains

“4/11 ผื่น 4 หน้า หู แพ้แสง ปาก ข้อ ไต หัว หัวใจ เลือด immuno ผลAna”

The acronym “ผื่น 4 หน้า หู แพ้แสง ปาก” refers to the cutaneous manifestations of SLE, particularly the malar rash (ผื่นหน้า), which is a butterfly-shaped rash across the cheeks and nose; discoid rash (ผื่นหู), photosensitivity (แพ้แสง), which is a skin reaction to sunlight, and oral ulcers painless (แผลปาก)

Adding “ข้อ ไต หัว หัวใจ เลือด” to the list includes oral ulcers painless (แผลปาก) arthritis (ข้อ), which often involves pain and swelling in the joints; renal involvement (ไต), which can present as proteinuria or active urinary sediment; neurological manifestations (หัว), such as seizures or psychosis; cardiac involvement (หัวใจ), which can include pericarditis; and hematological disorders (เลือด), like hemolytic anemia, leukopenia, lymphopenia, or thrombocytopenia. “Immuno ผลAna”

The “immuno” (คือ immuno) part refers to immunologic criteria such as the presence of antibodies like anti-dsDNA, anti-Sm, or antiphospholipid antibodies, which are significant for SLE. The ANA, or antinuclear antibody test (ผล Ana), is almost universally positive in SLE patients and is typically the first test ordered when the disease is suspected.

For a patient to be classified as having SLE according to the ACR criteria, they must satisfy at least four of the eleven criteria, either sequentially or simultaneously, during any interval of observation. This “4/11” rule helps in research classification and can also guide diagnosis in clinical practice.

And “ANA Immuno” (Ana และ Immuno) to remember the immunologic criteria and the importance of the ANA test.

This mnemonic fuses both languages to help remember the wide range of symptoms and tests associated with SLE.

Scleroderma, also known as systemic sclerosis, is a chronic connective tissue disease generally classified as one of the autoimmune rheumatic diseases. The hallmark of the disease is skin thickening and hardening, which can also involve structural changes to blood vessels and internal organs. Scleroderma is categorized into two main types: localized scleroderma and systemic sclerosis. Each has its own subtypes and distinct clinical manifestations:

1. Localized Scleroderma: This type affects only the skin, related tissues, and sometimes the muscle below. It does not involve the internal organs. The localized form is less severe and can be subdivided into:

  • Morphea: This presents as waxy patches on the skin that can be superficial or deep. Morphea patches are typically oval-shaped and may be white with a purple border.

  • Linear Scleroderma: This involves streaks or lines of hardened, thickened skin, which can affect the limbs, face, or forehead. It can sometimes cause deformities if it crosses a joint and restricts movement.

2. Systemic Sclerosis (SSc): This type affects the skin as well as the blood vessels and internal organs like the heart, lungs, kidneys, and gastrointestinal tract. Systemic sclerosis is further classified into:

  • Limited Cutaneous Systemic Sclerosis (lcSSc): This type used to be called CREST syndrome, an acronym for the main features: Calcinosis (calcium deposits), Raynaud's phenomenon (spasm of blood vessels in response to cold or stress), Esophageal dysfunction, Sclerodactyly (thickening and tightening of the skin on the fingers and hands), and Telangiectasias (dilated capillaries that can be seen through the skin). The skin thickening in lcSSc is generally restricted to the hands, forearms, face, and feet. People with lcSSc can develop pulmonary arterial hypertension (PAH) over time.

  • Diffuse Cutaneous Systemic Sclerosis (dcSSc): This type is characterized by more widespread skin involvement, which can rapidly progress to affect a larger area of the skin and internal organs. Early and significant internal organ involvement can occur, including kidney, heart, and lung (interstitial lung disease) complications.

The diagnosis of scleroderma is based on a combination of clinical signs and symptoms, laboratory tests, and, when necessary, biopsy. Antinuclear antibodies (ANAs) are commonly found in patients with scleroderma. Other specific antibodies associated with scleroderma include anti-Scl-70 (anti-topoisomerase I) and anti-centromere antibodies, which can help distinguish between subtypes and may predict the clinical course of the disease.

Management typically involves addressing the specific symptoms and organ involvement. For skin symptoms, treatments may include immunosuppressants, physical therapy, and phototherapy. For internal organ involvement, management is more complex and might involve treatments such as antifibrotic agents, vasodilators for PAH, proton pump inhibitors for gastrointestinal involvement, and immunosuppressive therapy for lung or kidney disease. Regular monitoring and supportive care are crucial parts of management.

Given the complexity and variability of scleroderma, a multidisciplinary approach is often necessary, involving rheumatologists, dermatologists, cardiologists, pulmonologists, gastroenterologists, and other specialists as needed.

Myositis (Polymyositis and Dermatomyositis):

Pathophysiology: Myositis is characterized by inflammation of the muscles, often due to an autoimmune response. The body's immune system attacks its own muscle fibers, leading to weakness, swelling, and pain.

Clinical Features:

  • Common symptoms include muscle weakness, swelling, pain, and fatigue.

  • In polymyositis, this muscle weakness is typically proximal and symmetrical.

  • Dermatomyositis also presents with distinctive skin rashes such as heliotrope rash and Gottron's papules.

Diagnostic Criteria:

  • A: Muscle Weakness - Proximal and symmetrical muscle weakness.

  • B: Elevated Muscle Enzymes - High levels of CK, AST, LDH, and aldolase.

  • C: Electromyography Changes - EMG showing myopathic patterns.

  • D: Muscle Biopsy Findings - Necrosis, phagocytosis, regeneration, perifascicular atrophy.

  • E: Skin Manifestations - Heliotrope rash, Gottron's sign, and other rashes such as Confluence Macular Violaceous Erythema (CMVE).


  • Polymyositis: Diagnosed when criteria A–D are met without the skin involvement (E).

  • Dermatomyositis: Diagnosed when the skin criterion (E) is present along with any combination of criteria A–D.

  • Mnemonics for Studying:

  • Muscle Weakness: "Weakness in Proximity" - Proximal muscle groups are primarily affected.

  • Elevated Muscle Enzymes: "Muscle Enzyme Elevation" - Enzymes rise like an elevator, indicating muscle damage.

  • EMG Changes: "EMG Electricity" - The erratic electrical activity of diseased muscles.

  • Muscle Biopsy Findings: "Biopsy Buzzwords" - Remember "Necrosis, Nurses, and Neighbors" for the main biopsy findings.

  • Skin Manifestations: "Skin Signs" - The sun (helios) turns the skin purple, with distinct signs (Gottron's).


  • Polymyositis and Dermatomyositis: Both conditions are managed with corticosteroids and immunosuppressive drugs. Physical therapy is vital to maintain muscle strength and flexibility.

  • Skin Management in Dermatomyositis: Additional treatments may be directed at the skin manifestations, which can include topical corticosteroids and antimalarial drugs like hydroxychloroquine for CMVE and other rashes.

Dermatomyositis Skin Rashes:

  • CMVE: "Confluence Macular Violaceous Erythema" - A key feature of dermatomyositis, presenting as flat, purple-red rashes that merge together.

  • V Sign: Rash on the chest and upper back in a 'V' distribution.

  • Shawl Sign: Rash on the shoulders and back.

  • Holster Sign: Rash on the hips/thighs.

By integrating these criteria with clinical features and management strategies, medical students can develop a comprehensive understanding of these conditions, which is crucial for both diagnosis and treatment. The mnemonics provided can serve as useful memory aids for recalling essential information during exams and in clinical practice.


 Explore the management and notable drug-related complications for each of these four common rheumatologic conditions:

1. Rheumatoid Arthritis (RA)


  • First-line: Methotrexate, a DMARD, is often the first choice. Alternatives or additions include sulfasalazine, hydroxychloroquine, and leflunomide.

  • Biologic agents, like TNF inhibitors (etanercept, infliximab), are used in cases unresponsive to traditional DMARDs.

  • NSAIDs and corticosteroids for symptom relief.

High-Yield Complications:

  • Methotrexate: Hepatotoxicity, pulmonary fibrosis, myelosuppression.

  • TNF inhibitors: Increased risk of infections, reactivation of latent tuberculosis.

  • Corticosteroids: Osteoporosis, hyperglycemia, increased risk of infection.

2. Systemic Lupus Erythematosus (SLE)


  • Mild cases: NSAIDs for joint pain, antimalarials like hydroxychloroquine.

  • Severe cases: High-dose corticosteroids, immunosuppressants like azathioprine, mycophenolate mofetil, or cyclophosphamide.

  • Belimumab, a biologic agent, for certain patients.

High-Yield Complications:

  • Corticosteroids: Long-term use can lead to Cushing's syndrome, osteoporosis.

  • Cyclophosphamide: Bladder toxicity, infertility, secondary malignancies.

  • Hydroxychloroquine: Retinal toxicity.

3. Scleroderma


  • Skin involvement: Methotrexate or mycophenolate mofetil.

  • Pulmonary arterial hypertension: Endothelin receptor antagonists (bosentan), PDE-5 inhibitors (sildenafil).

  • Raynaud’s phenomenon: Calcium channel blockers (nifedipine).

High-Yield Complications:

  • Calcium channel blockers: Hypotension, edema.

  • Endothelin receptor antagonists: Hepatotoxicity, teratogenicity.

  • PDE-5 inhibitors: Hypotension, headache.

4. Myositis


  • Corticosteroids as initial therapy.

  • Steroid-sparing agents like methotrexate or azathioprine in steroid-resistant cases.

  • Intravenous immunoglobulin (IVIG) may be beneficial in certain types.

High-Yield Complications:

  • Corticosteroids: Increased risk of infection, hyperglycemia.

  • Methotrexate: Hepatotoxicity, lung disease.

  • IVIG: Infusion reactions, renal dysfunction.

For all these conditions, regular monitoring and follow-up are crucial due to the potential for serious side effects of the medications. Management should be tailored to the individual patient based on disease severity, comorbidities, and response to treatment. Always remember that these diseases have a varying course and may require adjustments in therapy over time.

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