Rheumatology Exam Three Study Guide

Connective Tissue Diseases and Rheumatology

• Labs for Assessing Connective Tissue Diseases (CTDs): Includes anti-nuclear antibody (ANA) testing; clinical diagnosis is crucial as labs are not definitive.
• ANA (Antinuclear Antibody): Broadly screens for CTDs, excluding RA; a positive result may indicate aging or various diseases, including HIV and malignancies.
• SLE: Involves specific antibodies like dsDNA. Disease activity is monitored via titers; Anti-smith has decreased sensitivity.
• RA vs. OA:
  • Rheumatoid Arthritis (RA): Features symmetrical joint involvement, especially in hands. Characterized by cartilage loss, bone erosion, and involves synovium.
  • Osteoarthritis (OA): Involves complex risk factors including obesity and age, with x-ray findings showing narrowed joint space and osteophytes.
• Rheumatoid Arthritis Symptoms: Morning stiffness lasting over an hour, symmetrical swelling in joints, potential for complications like Felty’s syndrome.
• Environmental Triggers for RA: Smoking and infections can exacerbate the condition.
• Extrarticular Manifestations of RA: Include cardiovascular issues, various forms of vasculitis, and systemic effects like anemia.
• RA Treatment: NSAIDs as first-line; DMARDs like methotrexate, glucocorticoids for symptom management, and biologics for severe cases.

CREST Syndrome

• Definition: Limited scleroderma characterized by calcinosis, Raynaud's phenomenon, esophageal dysfunction, sclerodactyly, and telangiectasia.
• Complications: Can lead to pulmonary hypertension affecting heart and respiratory functions.

Gout

• Pathophysiology: Caused by uric acid accumulation, often due to renal excretion issues; acute, inflammatory arthritis defined by hyperuricemia (>6.8 mg/dL).
• Chronic Gout Treatment: Includes allopurinol; target serum uric acid less than 6 mg/dL. Tophi formation signifies aggravated condition.

Systemic Lupus Erythematosus (SLE)

• Key Features: Autoantibody disease with symptoms like butterfly rash, oral ulcers, and potential vasculitis presenting with purpura.
• Demographics: More common in women, especially African Americans.
• Lupus Treatment: IV/oral steroids, NSAIDs, hydroxychloroquine for arthritis, and cytotoxic immunosuppressants for severe organ damage.

Myasthenia Gravis

• Pathophysiology: Autoimmune disorder targeting acetylcholine receptors; characterized by muscle weakness, especially bulbar symptoms like ptosis and dysphagia.
• Presentation: Fatigue, respiratory failure; differentiated into generalized and ocular forms.

Duchenne Muscular Dystrophy

• Characteristics: Genetic condition affecting dystrophin; manifests with progressive weakness, often wheelchair dependence by ages 10-12.
• Diagnosis: Identified by elevated serum creatine kinase levels, presents with muscle fiber necrosis, and Gowers' sign.

Respiratory System Overview

• Breathing Control: Involves the pulmonary, musculoskeletal, and cardiac systems’ coordination; structures include conducting and respiratory zones.
• Bronchospasm and Inflammation: Inflammation can cause constriction of airway smooth muscle; role of acetylcholine in promoting bronchoconstriction via muscarinic receptors.
• Acute Respiratory Distress Syndrome (ARDS): Characterized by severe hypoxemia, bilateral infiltrates, and cytokine release; arises from pulmonary or extrapulmonary indirect injury.
• Pneumonia Symptoms: Includes systemic symptoms like fever, cough, and purulent sputum; physical examination reveals crackles and pleural rubs.

Asthma and COPD

• Asthma: Chronic inflammatory disease characterized by reversible airways obstruction; common triggers include allergens and irritants.
• COPD: Includes conditions like chronic bronchitis and emphysema, characterized by chronic inflammation leading to airway obstruction; symptoms include dyspnea and chronic cough.
• Diagnosis: Utilizes lung function tests such as spirometry; distinctions between “pink puffer” (emphysema) and “blue bloater” (bronchitis) based on clinical presentation.

Pediatric Considerations

• Wheezing Assessment: Age of onset, episodic nature, and response to treatment are crucial in assessing wheezing in children; common causes vary with age group.### Asthma Clinical History
• Most prevalent chronic lung disease globally characterized by chronic airway inflammation and hyperactivity.
• Airway obstruction is typically reversible but can progress to irreversible if poorly managed.
• Predisposing factors include family history, specific genetic markers (e.g., ADAM33 gene), atopy, premature birth, obesity, and exposure to secondhand smoke, recreational drugs, and smoking.

Asthma Subtypes

• Chronic asthma leads to irreversible changes, low FEV1 levels, and dyspnea in older patients.
• Exacerbations are acute worsens triggered by specific stimuli.
• Status Asthmaticus represents a life-threatening state with poor response to treatment.
• Bronchospasm results in increased airway constriction.
• Brittle asthma features rapid, severe exacerbations.
• Steroid-resistant asthma does not respond to corticosteroids.
• Cough variant asthma presents primarily with a mild cough, lacking wheezing.
• Occupational asthma results from inhaling allergens at work.

Diagnosis of Asthma

• Confirmed by showing reversible airway obstruction through treatment response, PEFR recordings, and spirometry before and after bronchodilators.
• Blood tests may reveal eosinophilia and elevated specific IgE levels.
• Chest X-rays can be normal or show hyper-expansion during acute attacks.
• Expiratory obstruction is typically worse than inspiratory, leading to air trapping.

Chronic Obstructive Pulmonary Disease (COPD)

• Second most common lung disease, primarily caused by inhaled irritants leading to airway inflammation and changes over time.
• Common symptoms include progressive dyspnea, chronic productive cough (often with sputum), wheezing, and manifestations of cor pulmonale (e.g., edema, headaches).
• Clinical signs include tachypnea, use of accessory muscles, barrel chest, and decreased bilateral lung expansion.
• Distinction between types:
  • Blue Bloater: primarily airway obstruction, chronic type 2 respiratory failure, cyanosis, and edema.
  • Pink Puffer: emphysema dominant, muscle wasting, increased respiratory effort, no cyanosis or edema.

Diagnosing COPD

• Diagnosis relies on spirometry, demonstrating obstructive and irreversible changes.
• PEFR often indicates low variability during exacerbations.
• FEV1 decline over time is common; additional assessments may include the PSI risk stratification tool.

Tuberculosis (TB)

• 10% of latent infections may reactivate, primarily caused by Mycobacterium tuberculosis.
• Infection occurs through droplet transmission and primarily affects alveolar macrophages.
• TB presents in pulmonary or extrapulmonary forms, with a Ghon focus indicating infection in the lungs.
• 50% transmission risk occurs even with exposure to an infected individual; key reactivation risk factors include age, immunosuppression (HIV), malnutrition, and smoking.

Wheezing Evaluation

• Bilateral wheezing indicates conditions like asthma and COPD.
• Unilateral wheezing may result from foreign body aspiration, tumors, bronchial compression, or lymphadenopathy.

Chest X-ray Indications

• Used to evaluate conditions associated with various pulmonary diseases, aiding diagnosis.

Cystic Fibrosis

• Affects 4% of Caucasians; autosomal recessive gene causing CFTR mutations leading to thick secretions and lung inflammation.
• Common complications: recurrent infections (notably by Pseudomonas aeruginosa), pancreatic insufficiency, and infertility in males.
• Clinical signs include clubbed fingers, barrel chest, and failure to thrive in infants.
• Diagnosis confirmed via sweat test showing elevated chloride levels.

Lung Cancer Risk Factors

• Strongly linked to smoking, with risk correlating with exposure intensity over time.
• Environmental factors include secondhand smoke, air pollutants (asbestos, radon), and certain pre-existing lung diseases.

Chronic Hypoxemia and Hypercapnia

• Hypoxemia denotes insufficient blood oxygen, while hypercapnia indicates elevated blood carbon dioxide (CO2).
• Respiratory failure is categorized into:
  • Type 1 (Hypoxemic): Characterized by low PaO2, common in acute lung diseases.
  • Type 2 (Hypercapnic): High PaCO2, potentially coexisting with hypoxemia, often seen in COPD or drug overdose cases.

CPAP Therapy for OSA

• Continuous Positive Airway Pressure (CPAP) machines maintain airway patency during sleep by providing air pressure.

Pulmonary Embolism (PE) Origins and Evaluation

• PE results from thrombus or other substances obstructing pulmonary arteries, with venous stasis, hypercoagulability, and vascular damage as contributing factors (Virchow’s triad).
• Diagnosis often utilizes imaging alongside clinical assessment, pretest probability, and D-dimer levels.

Pneumothorax Types and Management

• Traumatic pneumothorax can be closed (blunt trauma) or open (penetrating injury); spontaneous pneumothorax arises from ruptured blebs.
• Tension pneumothorax is a life-threatening condition requiring immediate chest tube placement to alleviate pressure.
• Stable patients can often be monitored while unstable patients require urgent intervention to stabilize respiratory function.

Treatment Protocols for Pneumothorax

• Small, asymptomatic pneumothoraces can be monitored; large pneumothoraxes may require chest tube placement.
• Surgical interventions may be necessary for recurrent or unresponsive cases, including VATS for pleurodesis and management of underlying conditions.

Prepare for your rheumatology exam with this comprehensive study guide focusing on labs to assess connective tissue diseases. Explore the complexities of diagnosing conditions such as SLE, RA, and Sjogren's, as well as the significance of anti-nuclear antibodies in clinical diagnosis. Ensure you're well-prepared with key insights into symptoms and differential diagnoses.