Pathophysiology Quiz 1

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Mix Flora
Components differ in various areas of the body
Pruritus
Itching
Topical agents to reduce sensation
May be treated by antihistamines or glucocorticoids
Contact Dermatitis
Etiology
Expose to an allergen
Type IV cell-mediated hypersensitivity reaction
Cosmetics
Plants
Contact Dermatitis
Pathophysiology
Sensitization occurs of first exposure
Direct chemical or mechanical irritation
Does not involve immune response
Is inflammatory because of direct exposure
Contact Dermatitis
Signs and Symptoms
More painful that pruritic
Range from mild erythema to hemorrhage, crusting, pustules

Diagnosis- Clinical evaluations

Treatment- Avoiding offending agents, corticosteroids
Urticaria (Hives)
Etiology
Result of Type I hypersensitivity
Ingestion of substances
Ex: Shellfish, drugs, certain fruits
Urticaria (Hives)
Pathophysiology
Lesions are highly pruritic
Often apart of anaphylactic shock
Urticaria (Hives)
Signs and Symptoms
Migratory, well- circumscribed, erythematous, pruritic plaques on the skin

Diagnosis
Clinical evaluation

Treatment
remove identified causes
symptomatic treatment (cool baths, loose clothing)
Antihistamines taken on a regular basis
Atopic Dermatitis (Eczema)
Etiology/Pathophysiology
Type I Hypersensitivity reaction
Atopic Dermatitis (Eczema)
Signs and symptoms
Common in infancy
Rash erythematous, with serous exudate
Commonly occurs on face, chest, and shoulders
In adults, rash is dry, scaly, and pruritic, often on flexor surfaces
Chronic inflammation results from response to allergens
Eosinophillia and increased serum IgE levels
Potential complication- secondary infections
Atopic Dermatitis (Eczema)
Diagnosis
Clinical evaluation

Treatment
Topical glucocorticoids, antihistamines
Psoriasis
Etiology
Results from abnormal T cell activation
Excessive proliferation of kerinocytes
Psoriasis
Signs and symptoms
Discrete, erythematous papules or plaques covered with thick, silvery, shiny scales

Diagnosis
Clinical evaluations

Treatment
Glucocorticoids, Coal tar preparations, antimetabolites
Pemphigus
Etiology
Autoimmune disorder

Pathophysiology
Autoantibodies disrupt cohesion between epidermal cells. (Layers fall apart)
Pemphigus
Signs and symptoms
Causes blisters to form
Skin sheds, leaving area painful and open to secondary infection.
Typically occurs first in the mouth
May be life threatening if extensive
Pemphigus
Diagnosis
Clinical evalutations
Sometimes biopsy

Treatment
Systemic glucocorticoids and immunosuppressants
Cellulitis
Etiology
Infection of the dermis and subcutaneous tissue
Usually staphylococcus aureus
Sometimes streptococcus
Cellulitis
Signs and Symptoms
Frequently in lower trunks and legs
Especially in individuals with restricted circulation in the extremities; also in immunocompromised individuals
Areas become red, swollen, painful, warm to the touch
Red streaks may develop, running along lymph vessels proximal to infected area

Diagnosis- Clinical Exam

Treatment- Antibiotics
Furuncles (Boils)
Skin abscess
Furuncles (Boils)
Etiology
Usually caused by S. aureus
Begins at hair follicles
Face, neck, back
Frequently drains large amount of purulent exudate
Carbuncles
Collection of furuncles that coalesce to form a large infected mass
Impetigo
Etiology
Infection from S. aureus

Signs & Symptoms
Superficial skin infection with honey-colored crusting or bullae
Highly contagious in neonates
Lesions commonly on face
Transmission may occur through close physical contact or through fomites
Pruritus is common
Leads to scratching and further spread of infection
Impetigo
Diagnosis -Examination

Treatment- Topical antibiotics in early stages
Necrotizing subcutaneous infection (acute necrotizing faciitis)
Etiology
Mixture of aerobic and anaerobic bacteria usually at site of infection.
Usually caused by virulent strain of gram-positive, group A beta-hemolytic streptococcus
Bacteria secrete toxins that break down fascia and connective tissue, widespread occlusion of subcutaneous vessels
Often a history of minor trauma or inflection in the skin and subcutaneous tissue of an extremity
Necrotizing subcutaneous infection (acute necrotizing faciitis)
Signs and Symptoms
Actuely ill, tachycardia, high fever, intense pain, affected tissue becomes rapidly discolored, muscles are spared initially

Diagnosis- Clinical exam, blood and wound cultures

Treatment- surgical debridement, antibiotics, amputation
Leprosy
Most cases in US involve people who emigrated from developing countries
How its spread is unclear, thought to be pass through nasal droplets and secretions
Casual short term interactions does not spread the disease
Even after contact with the bacteria, most people do not contract the disease
People who have leprosy probably have a genetic predisposition
Leprosy
Etiology
Chronic infection from Mycobacterium leprae
Leprosy
Signs and symptoms
Usually don't begin until after a year of infection
Skin macules, papules, nodules, peripheral numbness, destruction of nasal septum

Diagnosis- through microscope examination of skin biopsy

Treatment- primarily with antibiotics
Scabies
Etiology
Invasion by mite sarcpotes scabiei

Easily transmitted through physical contact
Scabies
Pathogenesis
Female burrows into epidermis
Lays eggs over a period of several weeks
Male dies after fertilizing the female
Female dies after laying eggs
Larvae migrate to skin surface
Burrow into skin in search of nutrients
Scabies
Signs and symptoms
Erythamatous papules appear in finger web spaces
Intensively pruritic
Burrows appear on skin as tiny, light brown or grey lines
Scabies
Diagnosis- Clinical evaluation, burrow scrapings
Treatment- Topical Scabicides
Pediculosis (Lice)
Etiology
infestation from pediculus humanus capitis- head louse
females lay egg on hair shaft
after hatching, louse bites human host, sucking blood for production of ova
Excoriations (abraded area) results from scratching
Transmission through close contact
Pediculosis (Lice)
Diagnosis- demonstration of living lice

Treatment- oral invemectin, topical pediculicide hair treatment.
Pediculosis (Lice)
No correlation between poor hygeine or low socioeconomic status
No evidence to support the need to clean belongings or take kids out of school.
Squamous Cell Carcinoma
Malignant Tumor of epidermal keratinocytes that invades the dermis
2nd most common type of skin cancer
Any non-healing lesion on sun exposed surfaces should be suspect
Squamous Cell Carcinoma
Signs and symptoms
may begin as a red papule or plaque
May have scaly or crusted surface
May become nodular
Squamous Cell Carcinoma
Diagnosis - biopsy is essential

Treatment - curettage, electrodesiccation, cryosurgery, topical chemotherapy
Malignant Melanoma
Malignant tumor of melanocytes
Occur mainly on skin but also on the mucosa of oral and genital regions and conjunctiva
About 40-50% develop from moles
Malignant Melanoma
Signs and symptoms -
The ABCD of Melanoma:
Malignant transformation is suspected in any lesion that shows:
Change in appearance
Change in border
Change in color
Increase in diameter
Malignant Melanoma
Diagnosis - biopsy
Treatment - curettage, electrodesiccation, cryosurgery
Osteomalacia
Adult Rickets
Osteomalacia
Etiology
Vitamin D deficiency
Inadequate dietary intake, lack of sunlight, malabsorption of vitamin D, errors in vitamin D synthesis
Lead to insufficient serum calcium
Osteomalacia
Signs and symptoms
Skeletal deformation particularly in bones with a predominance of cancellous bone
Looser's zone
Looser's zone
Radiolucent areas that may appear as fractures
Osteomalacia
Diagnosis
Low serum D3
Radiolucent patches in bone in x-rays

Treatment
Vitamin D supplementation
Rheumatoid Arthritis
Etiology
Unknown
onset is most often 25-50y
possible genetic predisposition triggered by viral infection
possibly an autoimmune disorder
Rheumatoid Arthritis
Pathophysiology
A type of type III hypersensitivity reaction
After antibody complexes imbed, inflammation of the synovial capsule develops
Later episodes will lead to the creation of pannus
erosion from pannus creates an unstable joint
over time the pannus becomes fibrotic and limits movement
Rheumatoid Arthritis
Signs and Symptoms
progressive joint inflammation predominantly in MCP and PIP joints
Symmetrical
joint tenderness
ulnar deviation of phalanges
periarticular pressure erosions of bone from soft tissue nodules
rheumatoid pannus (inflamed synovial tissue)
Rheumatoid Arthritis
Diagnosis
American College of Rheumatology:
If 4 of the following 7 are present, then positive for rheumatoid
Morning stiffness >=1 hour
Arthritis of >= 3 joints
Arthritis of hand joints
Symmetric arthritis
Rheumatoid nodules
Serum rheumatoid factor
Radiologic changes

Treatment
aspirin, NSAID, physical therapy
Synovitis
Inflammation of the synovial capsule
Pannus
Granulation tissue that has spread over the articular cartilage.
Releases enzymes and cytokines hat destroy the cartilage.
Ankylosis
Fixation or fusion of the joint due to the calcified pannus.
Duchenne's Muscular Dystrophy
Etiology -
X-linked recessive disorder leads to inability of muscle cells to repair sarcolemma
typically presents in boys 3-7y
Duchenne's Muscular Dystrophy
Signs and Symptoms -
Proximal muscle weakness
Causes waddling gait, toe-walking, lordosis
Difficulty climbing stairs
Pelvic girdle followed pectoral girdle
Most die by age 20
Gower's maneuver - pushing to a stand using the hands to climb up legs
Proximal near hips and vetebral muscles
Duchenne's Muscular Dystrophy
Diagnosis -
Clinical findings, family history, biopsy.

Treatment -
-No specific therapy, exercise encourage.
Vertebral disc herniation (slipped disc)
Nucleus pulposus leaks through the annulus fibrosus of the disc.
Vertebral disc herniation (slipped disc)
Etiology and pathophysiology-
Either age or trauma causes the collagen fibers of the annulus fibrosus to weaken allowing for the nucleus pulposus to leak through.
Vertebral disc herniation (slipped disc)
Signs and symptoms -
If the pulposus impinges on the spinal cord or spinal nerve, it can produce numbness or a shooting pain through a limb or in the body wall depending on the location of the herniation.
If the herniation does not impinge on the spinal cord, it can often be asymptomatic.
Vertebral disc herniation (slipped disc)
Diagnosis -
Patient history, spinal x-ray, CT scan, MRI

Treatment -
-Rest, pain relievers, muscle relaxants, removal of disc and spinal fusion
Osteoporosis
Bones are brittle and porous due to decreased amount of calcified tissue
Osteoporosis
Etiology and pathophysiology -
Most of the time it is idiopathic (no known cause)
It is often secondary to another disease (i.e. Cushing's disease) or menopause.
Postmenopausal women do not absorb dietary calcium well, therefore, calcium is liberated from the bone in order to maintain a proper serum calcium level.
Osteoporosis
Signs and symptoms -
Compression fractures in the spine, abnormally low bone density, aching pain in the spine.

Diagnosis -
x-ray, bone scan, MRI, bone biopsy

Treatment -
Increased dietary calcium, resistance exercise, hormone therapy.
Achondroplasia
short-limbed dwarfism
Achondroplasia
Etiology -
Autosomal dominant genetic defect
Mutation in FGFR3 (fibroblast growth factor receptor 3) gene

Pathophysiology
Defect produces irregular chondrocyte masses without architectural structure in epiphyseal cartilage.
A thin, horizontal plate of fibrous tissue and bone soon separates the cartilage from the epiphysis and its blood vessels, halting further extremity growth.
Membranous bone growth is not affected.
Autosomal
on one of the 22 non sex chromosomes
Achondroplasia
Signs and symptoms -
Bulky forehead, saddle nose, lumbar lordosis, bow legs.
Arms and legs are disproportionately short.
Head looks abnormally large but this is actually an illusion.
Head size is usually normal for age.

Management -
Surgical intervention to repair malformed joints.
Organizations that provide social contact.
Paget's disease
Bone cells are disorganized
"Puffy Bone"
Paget's disease
Etiology -
Combination of environmental and genetic, some suggest a viral cause

Pathophysiology
Genetic defect creates a profound increase in bone resorption and new bone formation resulting in a mix of lytic and sclerotic processes.
Defect over-activates signaling pathway that promotes osteoclast formation.
Paget's disease
Diagnosis -
Often accidentally through an x-ray taken for another reason.
Radionucleotide bone scan will show increased uptake at pagetic sites.

Treatment -
Localized and asymptomatic requires no treatment.
Chemotherapy to suppress bone cell activity.
Orthopedic surgery.
Sclerotic
The disorganized bone
Lytic
Where bone has been removed
Osteoarthritis
Pathophysiology -
Degenerative condition resulting in destruction of articular cartilage and hypertrophy of marginal bone.

Etiology -
Unknown
Age-related
Can be secondary to other conditions such as septic arthritis or trauma
Can also be caused by chronic overuse of a joint
Osteoarthritis
Signs and symptoms -
The knee is the most common location, but any joint can be affected.
Deep, aching joint pain.
Crepitation (creaking) may be heard in the joint.
Narrowing of the joint space in x-ray.
Presence of osteophytes (bone spurs) at joint margin.

Diagnosis -
Symptoms confirmed through x-ray
Osteoarthritis
Treatment -
Cannot be cured
Treat pain
Modify activity
Possible weight loss
Joint replacement surgery
Gout
chronic disorder of uric acid metabolism
Gout
Etiology and pathophysiology-
Cause may be metabolic, renal, both, or genetic defect
Metabolic is inherited, renal is caused by renal dysfunction.
Crystals of uric acid compounds are deposited on synovial joint margins.

Signs and symptoms -
Sudden onset of joint pain in the first metatarsophalangeal joint, although other joints may be involved.
Pain reaches a peak and then subsides which may be accompanied by mild fever and chills.
Gout
Diagnosis -
Identification of tophi in xray.
Urinalysis to reveal hyperuricemia.

Treatment -
- bed rest, analgesics, anti-inflammatory drugs, low-purine diet (meat, fish, chicken, mushrooms, peas, asparagus, etc.)
Carpal tunnel syndrome
Etiology -
Compression of median nerve between the flexor retinaculum and carpal bones

Pathophysiology -
Overuse causes swelling of the flexor tendon sheaths which presses on the median nerve
Carpal tunnel syndrome
Signs and Symptoms -
Pain, numbness, paralysis, and burning in the hands

Diagnosis -
- patient history, positive Tinel's sign (tingling in skin produced by pressing or tapping on damaged nerve trunk)
Myasthenia Gravis
chronic, progressive, neuromuscular disease producing sporadic weakness and exhaustion of skeletal muscles
Myasthenia Gravis
Etiology -
- unknown, at some point most often between 20 and 40 years of age, Pathophysiology -

Pathophysiology -
Autoimmune response to membrane receptors for acetylcholine, antibodies toward the receptors are formed.
Prevents transmission of nerve impulse to muscle cell
Myasthenia Gravis
Signs and symptoms -
First notice double vision and droopy eyelids
Blank expression, difficulty swallowing, head bobbing

Diagnosis -
Improvement of muscular function after injection with anticholinesterase drugs that prevent the breakdown of acetylcholine
Serum antibodies

Treatment -
- supportive, anticholinesterase drugs, corticosteroids
- no known cure