Musculoskeletal System Inflammatory Disorders NCLEX Exam

Musculoskeletal Disorders

• Inflammation of muscle, bone, and joints (Rheumatology)
• Gout and Rheumatoid Arthritis are common inflammatory disorders of the musculoskeletal system

Bone Structure and Infection

• Bone is normally resistant to infection
• Infection occurs due to break in bone or through the bloodstream
• Bacteria invade the cortex via Haversian and Volkmann canals
• Risk factors for bone infections include immunosuppression, comorbid diseases (e.g., diabetes mellitus), and nutritional deficiency
• Prosthetic material can also increase the risk of infection

Osteomyelitis

• Infection of bone, usually due to bacterial infection (Staphylococcus aureus)
• Three categories: hematogenous, contiguous, and chronic
• Presentation: recent infections, chills, fever, malaise, localized tenderness, erythema, edema, and reduced ROM in affected area

Gout

• Hyperuricemia triggers inflammation
• Affects specific joints (e.g., first metatarsal)
• Podagra: acute inflammation of the metatarsophalangeal joint of the great toe
• Primary and secondary forms
• Uric acid crystals may be deposited in subcutaneous tissue (“tophi”)
• Patient presents with redness, warmth, swelling of the joint, and discomfort onset during night or early morning

Risk Factors for Gout

• Diet high in meat (purines: uric acid)
• High alcohol consumption
• Obesity and yo-yo dieting
• Family history
• Chemotherapy resulting in cellular destruction
• Medications

Psoriatic Arthritis (PsA)

• Chronic, autoimmune inflammatory disease
• Psoriatic skin disease precedes joint disease
• Immunoglobulins deposition in epidermis
• Patterns: distal interphalangeal (DIP) predominant, arthritis mutilans, symmetric arthritis, asymmetric arthritis, and spondylitis

Symptoms of PsA

• Pain
• Swelling
• Erythema of affected joints
• Generalized fatigue
• Redness
• Eye pain
• Plaque psoriasis of the skin
• Psoriatic nail changes (pitting, ridging, and onycholysis)

Diagnosis of PsA

• Lab tests only somewhat helpful
• Need to differentiate from other arthritis forms
• Skin and nail changes are important for diagnosis
• In later stages, x-rays may show characteristic changes

Treatment of PsA

• Methotrexate
• NSAID’s
• Disease-modifying antirheumatic drugs (DMARD’s)
• Specifically TNF inhibitors

Lyme Disease

• Bacterial disease: Borrelia burgdorferi
• Transmitted by ticks (Ixodes scapularis)
• Incubation period: 7 to 14 days
• Fewer than 50% of individuals recall tick bite
• Disease manifestation due to infection and immune response

Stages of Lyme Disease

• Early localized (3–30 days post-bite): fever, myalgias, erythema migrans
• Early disseminated (3 to 12 weeks post-bite): vague, generalized symptoms, lymphocytic meningitis, cranial neuritis, carditis, and ocular involvement
• Late disseminated (months to years after bite): severe joint pain and swelling of large joints, central nervous system involvement, polyradiculopathy symptoms