Transcript CHapter 21 Skin Diseases TJC

Diseases
What to Remember.
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VERY Large volume of information.
DO memorize :
1. Disease - etiological agent. (plague, Y. pestis)*
2. Characteristics of agent (Gram +, rods, produces toxin, etc)
3. Hallmark symptoms (only 1 disease has).
4. Route of entry and body system the disease affects.
5. Source of infection (food, water, insect bite, spontaneous,
etc.)
6. Target population (children, geriatric patients, anyone, etc.)
* All 50 in your list match except 6 or 7.
Diseases
What to Remember.
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VERY Large volume of information.
Do NOT to memorize :
1. General symptoms (fever, headache, malaise, etc.).
2. Diagnosis - Dx - (unless otherwise indicated).
3. Antibiotic Treatment - Rx (they change with resistance).
and the existence of a vaccine unless it’s a childhood vaccine.
4. Trivia (Historical facts, famous people, etc.).
Bacterial Diseases
Boils,
pimples, abscess (p. 578)*
Impetigo (p. 580)
Acne (p. 580)
Pseudomonas Infections (p. 580)
Eye Infections (p. 592)
Skin and Eye
Anatomy
• Skin- dermis
• Epithelial cells- keratinized.
• Sebaceous glands - oil.
• Hair follicles.
• Sweat glands.
• pH 5.5
• few pathogens can
penetrate
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Skin and Eye
Anatomy
Normal flora
Sweat and sebum feed flora.
Staphylococcus aureus & epidermidis
Lactobacillus sp.
Corynebacterium sp.
Proprionibacterium acnes
Streptococcus sp.
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Skin and Eye
Anatomy
Eye - almost sterile due to flow of tears.
Lysozyme found in tears- bactericidal.
Conjunctiva and cornea most vulnerable.
NO normal flora.
Skin Diseases
• Boils, pimples, abscesses- folliculitis
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Staphylococcus aureus and epidermidis
Gram + coccus
• Catalase, coagulase+
• - hemolytic
• leukotoxin
can develop into bacteremia
scalded skin syndrome- exfoliatins
TSS (Toxic Shock Syndrome)
Rx -clindamycin, vancomycin, oxacillin
Skin Diseases
• Streptococcal Skin Infections
Strep. pyogenes (group A Strep) in chains
 -hemolysins -streptolysin
 M - protein, antiphagocytic
 flesh eating disease (necrotizing fasciitis)
 Scarlet Fever - respiratory with dermal signs***
 treat with antibiotics, surgery
 Rx - cephalosporins, vancomycin
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Erysipelas-
severe infection of the skin
 can develop into necrotizing fascitis
 Rx - cephalosporin
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Skin Diseases
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ImpetigoStreptococcus pyogenes*
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Gram + cocci, chains
-hemolytic, M protein Anti-phagocytic,
 streptokinase dissolves blood clots, heart attacks
 hyaluronidase- dissolves tissue cement
 Problem mainly in children.
 Is contagious and can spread by contact.
 Rx - Hygeine
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Topical antibiotics Mupirocin
Oral antibiotics in severe cases*; cephalosporin;
methicillin, tetracycline
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*due to kidney involvement
Skin Diseases
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Acne
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Propionibacter acnes
Gram + rod, anaerobe
 Diphtheroid,
 17 million cases
 Breaks down sebum to glycerol for energy metabolism Produces lactic acid, propionic acid, and acetic acid as end-products.
 OTC- benzoyl peroxide
 Rx ~ tetracycline, doxycycline,
 Retin A, accutane (reduces sebum)
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Skin Diseases
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Burn infections - Pseudomonal
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Pseudomonas aeruginosa
Gram – motile rod
 Obligate aerobe.
 Co-infection with C. perfringens can lead to gas gangrene.
 Opportunistic pathogen for burn and geriatric patients.
 Produces pyocyanin green toxin, kills cells.
 Two extracellular proteases:
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elastase ~cleaves IgG, IgA, & collagen.
 alkaline protease lyses fibrin.
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Produces leukocidin, and 2 hemolysins.
 Resistant to many antibiotics
 Rx ~ fluoroquinolones; gentamicin + carbenicillin (severe cases).
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Eye Diseases
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Conjunctivitis - pink eye
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Hemophilus influenzae - pink eye
Gram negative rod
 blood loving
 inflames conjunctiva
 Tx- self limiting
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๏ Inclusion Conjunctivitis and
Trachoma
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Chlamydia trachomatis
 Atypical Gram negative, OIP.
 causes corneal and eyelids, can lead to
blindness. (worldwide #1 cause)
 Rx - azithromycin
QuickTime™ and a
decompressor
are needed to see this picture.
Skin Diseases
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Viral Diseases
Rubella (German Measles) (p. 582 )
Measles Rubeola (p. 583 )
Chickenpox -Shingles (p. 584 )
Smallpox (p. 585 )
Warts (p. 587 )
Skin Diseases
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Rubella
German (3 day) Measles
 ssRNA - Togavirus
 Much milder and shorter in duration
 Congenital form more serious - causes
serious birth defects.
 If in 1st trimester can lead to heart
defects, mental retardation, or death.
 Vaccine introduced in 1969 to prevent
congenital form.
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Skin Diseases
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Rubella
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German (3 day) Measles
 Rate
dropped dramatically after vaccine licensed in 1969.
(herd immunity)
 Vaccine part of MMR vaccine regimen (@ 1 yr, 5 yrs).
 Dx - 4 fold increase in Rubella IgM titer.
 Rx - none
Skin Diseases
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Rubeola
Measles
RNA - Paramyxovirus
7th Century AD
Entry respiratory
Incubation 10-12 days.
21 days - Koplick’s spots in mouth. (Hallmark)
Red rash spreads from arms to trunk and face, then legs.
1 in 1000 develops encephalitis - 30-50% die; 30% brain damage.
Dx - Can tell difference in rash and progression.
Skin Diseases
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Rubeola
Measles
Koplick’s spots in mouth.
Skin Diseases
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Rubeola
Measles
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Vaccine ~ 1963
Childhood vaccinations have greatly
reduced incidence.
Vaccine 95% effective.
< 100 cases / yr.
Most cases imported.
In 2000 - #5 killer of children worldwide.
Rx - none. MMR vaccine
Skin Diseases
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Herpes zoster
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Chickenpox
DNA virus
 Respiratory  2 weeks - Skin vesicles erupt.
 Virus infects peripheral nerves.
 Mortality low but higher in adults.
 Can invade blood vessels cause hemorrhaging and blood clots.
 Viral pneumonia also possible.
 Vaccine -1995; required for college admission.
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Skin Diseases
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Herpes zoster
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Chickenpox
Vaccine -1995
 Dx - history, symptoms.
 Tx - none; make comfortable; control fever.
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Shingles
In adults with low VZV antibody titers.
 Virus has invaded nerve cells; causes skin eruptions.
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Skin Diseases
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Herpes zoster
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Chickenpox
Shingles
Virus infects peripheral nerves migrates to
CNS.
 Remains latent (characteristic of Herpes).
 Later in life (decades) can migrate back
down nerve and cause skin eruptions shingles.
 Rx - booster vaccine (Zostavax) those
>60.
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Skin Diseases
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Variola major
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Smallpox
DNA virus - very large
 Respiratory - to organs and skin
 Dermal lesions - very infectious.
 first symptoms of smallpox include fever, malaise,
head and body aches, and sometimes vomiting.
 rash emerges first as small red spots on the tongue and
in the mouth. At this time, the person becomes most
contagious.
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Skin Diseases
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Variola major
Smallpox
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A rash appears on the skin, starting on the
face and spreading to the arms and legs and
then to the hands and feet. Usually the rash
spreads to all parts of the body within 24
hours. As the rash appears, the fever usually
falls and the person may start to feel better.
By the 3rd day, the rash becomes raised
bumps.
By the 4th day, the bumps fill with a thick, opaque fluid and often have
a depression in the center that looks like a bellybutton - a major
distinguishing characteristic of smallpox. Fever often will rise again at
this time and remain high until scabs form over the bumps.
Skin Diseases
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Variola major
Smallpox
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The bumps become pustules —
sharply raised, usually round and firm
to the touch as if there’s a small round
object under the skin.
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The pustules begin to form a crust and then scab. By the end of the
second week after the rash appears, most of the sores have scabbed
over.
Most scabs will have fallen off 3 weeks after the rash appears. The
person is contagious to others until all of the scabs have fallen off.
FIRST disease eradicated by man. No cases in USA since 1949. Last
natural case in the world - 1977 Somalia.
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Skin Diseases
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Variola major
Ramses V -1000 BC
Smallpox
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History
Known to exist since 10,000 BC !
India & China for centuries, and Syria in 302
AD.
Crusaders brought back to Europe in the 1100’s.
Spaniards took to W. Indies in 1500’s; Cortez to Mexico in 1520.
American Indians devastated in the 1800’s. British used as a
bioweapon during French & Indian wars.
Montague introduced vaccination in England in 1717- Jenner in 1796.
WHO announced disease eradicated on May 8, 1980.
Skin Diseases
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Human Papilloma virus (HPV)
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Warts - Condyloma acuminata
ssDNA virus
 naked, polyhedral
 Incubation - months
 Benign growth
 Genital forms can go malignant - STD
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Virus infects replicating skin cells in stratum
basal.
 As cells mature the viral load increases.
 Causes increased layers of stratum corneum.
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Tx- laser or electro- removal, cryosurgery.
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Skin Diseases
Human Papilloma virus
(HPV)
Warts - Condyloma acuminata
Genital warts can lead to cancer.
HPV serotypes 16, 18, 31, 45
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4 strains account for about 70% of tumors.
HPV vaccine - 2006, 100% effective.
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1% develop visible external warts.
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50% of sexually active women will encounter HPV in their lives.
Must receive before becoming sexually active.
3 doses. (2 mo. and 6 mo. after first)
Immunity ? > 5 years.
Intended to reduce cervical cancer.
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Skin Diseases
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Fungal Diseases (p. 589)
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Tinea infections
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Ringworm- T. corporis
Jock itch - T. cruris
Athlete’s foot - T. pedis
Dx - signs, skin scrapings.
Tx- remove dead skin, apply topical ointments. Anti-fungal
agents include tolnaftate, griseofulvin, miconazole.
Skin Diseases
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Fungal Diseases (p. 591)
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Candida infections- C. albicans
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Yeast infections (thrush, vaginitis)
Thrush can be due to antibiotic therapy,
AIDS, diabetes, and immunosupression.
Usually a secondary infection.
Dx- signs.
Tx - correct debilitating conditions. Thrush - gargle with nystatin.
Vaginitis or Bacterial Vaginosis will be covered in the
Reproductive Tract diseases.
Skin Diseases
THE
END
YEAH !