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DISEASE AND CAUSES
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PATHOPHYSIOLOGY
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SIGNS AND SYMPTOMS
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Actinomycosis
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Bacterial infection due to a variety of gram-positive anaerobic or microaerophilic rods, mostly of genus
Actinomyces
- Occurs most frequently at an oral, cervical, or facial site
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A disruption of the mucosal barrier permits actinomyces to invade beyond their endogenous environment in the mouth, lower GI tract, and female genitourinary tract causing local inflammation of the area and progressing to lesions with fibrous walls and sinus tracts. |
Oral, cervical, or facial site:
- Infectious lesion of head and neck
- Pain
- Fever
- Leukocytosis
- Otitis, sinusitis, and canaliculitis
Extension to cranium, spine or thorax:
- nuchal rigidity
- exaggerated deep tendon reflexes
- decreased level of consciousness
- cough with occasional hemoptysis
- fever
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Adenoid hyperplasia
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- Cause unknown; may be hereditary or due to chronic infections or irritations
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Increased mitosis leads to an increase in cell numbers in adenoid tissue. |
- Respiratory obstruction, especially mouth breathing, snoring at night, and frequent, prolonged nasal congestion
- Persistent mouth breathing during the formative years
- Frequent otitis media
- Sinusitis
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Adrenogenital syndrome
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Autosomal recessive disorder that causes a 21-hydroxylase deficiency or 11-
b
hydroxylase deficiency
- Tumor of the adrenal glands
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Lack of an enzyme needed to synthesize cortisol causes an excessive ACTH response through the negative feedback loop to the pituitary. The continual ACTH message to the adrenal glands results in hyperplasia of adrenal tissue. Excessive androgen production is stimulated because the adrenal pathway to androgen production is not blocked. |
- Enlarged external genitalia in newborn due to excessive androgen production; female infants may have slightly enlarged clitoris or clitoris with a penile shape and labia fused to appear as a scrotum, whereas males have enlarged genitals
- Severe electrolyte imbalance, dehydration, vomiting, wasting, and shock due to adrenal crisis at 5 to10 days
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Albinism
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- Autosomal recessive inheritance
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Absence of the enzyme tyrosine results in a defect in melanin formation. |
- Extremely fair skin color
- Fine, white hair
- Gray or blue irises of the eye
- Strabismus
- Nystagmus
- Photophobia
- Persistent loss of visual acuity
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Alpha
1
-antitrypsin deficiency
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- Autosomal recessive inheritance
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Reduced or absent levels of alpha
1
-antitrypsin, which is needed to inhibit proteolytic enzymes, leads to the unopposed action of protease on the liver and lungs.
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In children:
- Cholestasis
- Hepatitis
- Portal hypertension
In young adults:
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Amblyopia
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- Strabismus in children
- Excessive alcohol or tobacco use in adults
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Acuity is reduced due to a toxic reaction in the orbital portion of the optic nerve or by cerebral blockage of the visual stimuli. |
- Visual dimness, photophobia, and ocular discomfort
- Small central or pericentral scotoma enlarges slowly
- Temporal disk pallor
- Possible blindness
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Amyloidosis
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- Pressure due to accumulation and infiltration of amyloid causes atrophy of nearby cells. Abnormal immunoglobulin synthesis and reticuloendothelial cell dysfunction may occur
- Familial inheritance in persons with Portuguese ancestry
- May occur with tuberculosis, chronic infection, rheumatoid arthritis, multiple myeloma, Hodgkin's disease, paraplegia, brucellosis, and Alzheimer's disease
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A rare, chronic disease of abnormal fibrillar scleroprotein accumulation that infiltrates body organs and soft tissues. Perireticular type affects the inner coats of blood vessels whereas pericollagen type affects the outer coats. Amyloidosis can result in permanent, even life-threatening, organ damage. |
- Proteinuria, leading to nephrotic syndrome, eventually to renal failure
- Heart failure due to cardiomegaly, dysrhythmias, and amyloid deposits in subendocardium, endocardium, and myocardium
- Stiffness and enlargement of tongue, decreased intestinal motility, malabsorption, bleeding, abdominal pain, constipation, and diarrhea
- Appearance of peripheral neuropathy
- Liver enlargement, often with azotemia, anemia, albuminuria and, rarely, jaundice
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Ankylosing spondylitis
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- Cause unknown; strongly associated with presence of human leukocyte antigen (HLA)-B27
- Familial inheritance
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Fibrous tissue of the joint capsule is infiltrated by inflammatory cells that erode the bone and fibrocartilage. Repair of the cartilaginous structures begins with the proliferation of fibroblasts, which synthesize and secrete collagen. The collagen forms fibrous scar tissue that eventually undergoes calcification and ossification, causing the joint to fuse or lose flexibility. |
- Intermittent low back pain that is most severe following inactivity or in the morning
- Stiffness, limited lumbar spine motion
- Pain and limited expansion of chest
- Peripheral arthritis in shoulders, hips, and knees
- Kyphosis in advanced stages
- Hip deformity and limited range of motion
- Mild fatigue, fever, and anorexia or weight loss
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Anthrax
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Infection of the skin, lungs, or GI tract that results from contact with contaminated animals or their hides, bones, fur, hair, or wool by
Bacillus anthracis
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After infection, bacterium produces toxins that enter susceptible cells, leading to cell death; mechanism unknown. |
Incubation is 12 hours to 5 days.
- Red-brown bump on skin enlarges and swells around edges; a black scab forms after the bump blisters and hardens
- Swollen lymph nodes
- Muscle ache and headache
- Nausea, vomiting, fever
In pulmonary anthrax:
- Respiratory problems
- Shock and coma
In GI anthrax (rare):
- Extensive bleeding and kills tissue
- Fatal if enters the bloodstream.
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Aspergillosis
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- Fungal infection due to Aspergillus species; transmitted by inhalation of fungal spores or invasion of spores through wounds or injured tissue
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Aspergillus
species produce extracellular enzymes such as proteases and peptidases that contribute to tissue invasion, leading to hemorrhage and necrosis.
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Incubation is a few days to weeks; may be asymptomatic or mimic tuberculosis, causing a productive cough and purulent or blood-tinged sputum, dyspnea, empyema, and lung abscesses
- Allergic aspergillosis causes wheezing, dyspnea, pleural pain, and fever
Aspergillosis endophthalmitis appears 2 to 3 weeks after eye surgery
- Cloudy vision, eye pain, and reddened conjunctiva
- Purulent exudate on exposure to anterior and posterior chambers of the eye
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