Pathology Components and Examples

Pathology Components

• Pathology is the study of disease causes and effects.
• Four main components:
  • Etiology: The cause of the disease.
  • Pathogenesis: The mechanism by which the disease develops.
  • Morphology: The physical changes in the body due to the disease.
  • Symptomology: The clinical signs and symptoms of the disease.

"The Lost Foot" Example

• Etiology: Alligator bite.
• Pathogenesis:
  • Alligator teeth damage skin and bone, leading to bleeding and pain.
  • Inflammatory response develops in injured tissue.
  • White blood cells phagocytose (engulf and destroy) affected tissue.
• Morphology: The foot is lost.
• Symptomology:
  • Loss of lower leg below the knee.
  • Redness, swelling, pus, and bleeding from the wound.
  • Potential pain at the site.

Rheumatoid Arthritis (RA) Markers

• Rheumatoid Factor (RF): An antibody found in some RA cases indicating joint inflammation.
• HLA-B27: A genetic marker commonly associated with ankylosing spondylitis (AS), also seen in some other spondyloarthropathies.
• Rheumatoid Arthritis Types:
  • Seropositive RA: Positive blood test (RF).
  • Seronegative RA: Negative blood test (RF), but still exhibits RA symptoms.
• Related Conditions:
  • Ankylosing Spondylitis
  • Psoriatic Arthritis (autoimmune condition affecting joints)

Seronegative Arthritis (e.g., Psoriatic Arthritis)

• Prevalence: Impacts 2-5% of the US population
• Association with Psoriasis: 10-30% of psoriasis sufferers also have psoriatic arthritis.
• Characteristics:
  • Autoimmune disorder with genetic tendencies
  • Primarily affects hands and feet.
  • Sacroilitis (inflammation of the sacroiliac joints) is common.
  • "Pencil cup" deformity (a specific hand shape) is a classic sign.
  • Pitting of nails is common.
  • Usually unilateral joint involvement (one side at a time).
  • Associated complications (non-joint related): iritis, colitis, etc.
• Treatment:
  • NSAIDs (non-steroidal anti-inflammatory drugs)
  • SAARDS (disease-modifying antirheumatic drugs)
  • Rehab for affected joints (e.g., hand wax therapy, exercise).
  • UV therapy for psoriasis.

Impairment, Disability, Handicap, Condition

• Condition: The diagnosis.
• Impairment: The loss or derangement of a body part, system, or function (physical and/or cognitive).
• Disability: Limitations on performing activities, potentially resulting from impairments.
• Handicap: Restrictions on participation in society due to environmental factors and disability.

Medical Conditions (Examples)

• Diseases, illnesses or injuries
• Physiological, mental , or psychological disorders

Impairment Definition

• Actual physical, cognitive, or emotional limitation due to a condition.
• AMA Guides definition: "The loss, loss of use, or derangement of any body part, system, or function."

Disability Definition

• Limitation on performing activities in the normal range.
• WHO definition: "any restriction or lack of ability (resulting from any impairment) to perform an activity in the manner or within the range considered normal for a human being".
• Relevant to specific criteria for disability (e.g., worker's compensation, insurance).

Handicap Definition

• Restriction on participation in normal functions due to environment.

Lumbar Radiculopathy (LDDD)

• Common Location: Most common at L5/S1 (lower back spine).
• Association with Sciatica: Can lead to the characteristic sciatica pain due to nerve compression.
• Symptoms:
  • Numbness.
  • Weaknesses in legs.
• Physical Characteristics:
  • Loss of normal lumbar spine movement.
  • Weak abdominals.
  • Possibly increased lumbar lordosis.