Lecture 2: Infectious Diseases Affecting Skin, Soft, Tissue, and Eyes

Question 1

Dysbiosis

Answer 1

sustained alteration of microbiota resulting in overt inlammation

Question 2

Functions of skin

Answer 2

protects uderlying tissues from microbial colonization

Each layer with specific activities
epidermal with keratinocytes (producted in stratum basal, die in stratum corneium, dry & waterproof) with dendritic langerhang cells

Dermal: sweat glands, sebceous glands

Question 3

Skin microbiota

Answer 3

protects deeper tissues from infections

Question 4

Sebaceous sites of skin have…

Answer 4

…the lowest bacterial diversity

Question 5

Moist sites of skin colony examples

Answer 5

Staph and coryneobacterium (gram +)

Question 6

Dry sites of skin colony examples

Answer 6

highest diversity, s epidermidis, and gram - species

Question 7

Acne

Answer 7

most common skin disease in world

chronic, inflammatory condition sometimes involving cutibacterium acnes

c. acnes part of normal microbiota

Question 8

Pilosebacceous unit

Answer 8

hair follicle + sebaceous gland
*plugged sebaceous glands can deveop into papules or nodules

sebum+ c.acnes in pores can lead to acne

Question 9

Biofilms

Answer 9

endogenous microbiota can form biofilms

biofilm=any group of microorganisma in which cells stick together and adhere to a surface

thrive in warm, humid climates

Question 10

Staphylococci

Answer 10

Gram + spheres form clustered arrangements

several species cause disease: S. aureus (MRSA, MSSA), S. epidermidis, S. Saprophyticus (UTIs)

makes coagulase- if it is coagulase + that is indicitive of S. aureus

produce catalase, converts h2o2 to water and o2. Catalase test is useful to distinguish staph from streptococci and enterococci

Question 11

MRSA

Answer 11

caused by staph aureus

-resistant to all beta-lactams/cephalosporins (*EXCEPT: ceftobiprole & ceftaroline)

Question 12

Staphylococcal Contact Diseases 2 types

Answer 12

1. Localized skin infections: abcess, folliculitis, furnuncle
2. toxin generated diseased: impetigo, scalded skin syndrome, toxic shock syndrome (TSS)

Question 13

Abcess

Answer 13

Pus-filled lesion on skin normally in dermis

Question 14

Folliculitis

Answer 14

puss-filled pocket at base of hair folliclue

caused by Grp A streptococcus

Question 15

Furnuncle

Answer 15

infection further down hair follicle, carbuncle group of furnucles

large, warm, painful

caused by grp A streptococcus

Question 16

Streptococci

Answer 16

gram-positive

normal skin inhabitant

grow in chains

Question 17

Streptococci classification systems

Answer 17

Hemolytic groups: behavior on blood agar

• aplha- olive green
• beta-clear
• gamma- no change

Variants of cell wall carbs:

• Grp A= s. pyogenes
• Grp B= s. agalactiae

*important because each species treated diff

Question 18

Cellulitis

pathogen
morphology

Answer 18

P: Grp A Streptococci
M: Non purulent (no puss associated)
severe infection of dermis and SQ tissue
skin erythema, edema, warmth

Question 19

Streptococcal pharyngitis pathogen

Answer 19

P: Grp A Streptocci

“strep throat”

Question 20

ErySipelas

Pathogen
morphology

Answer 20

P: Grp A Streptococci
M: superficial form of celluitis of dermis
upper dermis with clear demarcation between involved and uninvolved

Question 21

Stretococcal TSS

pathology
prognosis
smyptoms
risk factor

Answer 21

P: Grp A Streptococci
PG: high mortality w/o treatment
S: high fever, low BP, vomiting, rash
Rx: recent sx, open wounds, super absorbent tamptons

Question 22

Necrotizing fasciitis

Pathogen

Answer 22

P: caused by Grp. A streptococcus

M: erythema, edema, severe pain, fever, skin bullae, necrosis usually involving extremetites

Question 23

Gas gangrene/ myonecrosis

Pathogen & characteristics
Morphology
Treatment

Answer 23

P/C: clostridium perfringens
anaerobic, gram +, spore forming rod

M: foul odor, intense pain, swelling, black skin

Tx: treat with antitoxin, and antibiotics

Question 24

Cutaneous Anthrax

Pathogen & Characteristics
Treatment
Morphology

Answer 24

P/C: B. anthracis
aerobic, gram positive rod

Tx: treat with antibiotics
*normally for people who work with sheep

M: begins as small pruruitc papuale but formes into central vesicle or bulla
*eschar with with extensive surrounding edema is the hallmark

Question 25

Wound cellulitis Pathogen/characteristics treatment risk factor

Answer 25

P/C: psuedomonas aeruginose aerobic, gram-negative tx: debridement and antibiotis rx: can happen especially after burns

Question 26

Pasteurellosis Pathogen/characteristics risks treatment

Answer 26

P: pasterurella multocida aerobic, gram-, Rx: dog or cat bites tx: treat with penicillin

Question 27

Cat scratch disease Pathogen Morphology/Symtoms treatment

Answer 27

P: bartonella henselae M/S: red-crusted blisters, headaches, malaise and low grade fever, swollen lymph nodes tx: antibiotics for 2-4 months

Question 28

Cold Sores

Answer 28

HSV-1, simplexvirus family of herpesviridae after primary infection, virus becomes latent in sensory ganglia near spine, and travels back to skin along nerves to form blisters recurrent cold sores occur when viruses are reactivates and move to the epithelium

Question 29

chicken pox Pathogen Transmission Morphology Complications

Answer 29

P: varicella-zoster virus from varicellovirus family of herpesviridae infection in sensory nerve ganglia can become shingles **not longer prevalent in US due to vaccine that became available in 1995 T: transmitted from skin to skin contact and respiratiory droplets M: red, itchy rash turns into fluid filled blisters- which have highly infectious virus laden fluid C: most common complication is a bacterial infection of the skin -pneumonia, encephilits, or reyes syndrome can also occur

Question 30

Shingles

Answer 30

caused by same virus as chicken pox VZV remains latent in nerve cells for many years if reactivated they can travel to the body trunk and cause blisters and patches of red can also cause facial paralysis and severe ice tick pains can occur repeatedly? postherpetic neuralgia is persistence of pain for years after blisters have disappeared

Question 31

human herpes virus 6 causes what diseases? spread by...

Answer 31

family of beta-hyperseviridae primarily occur in infancy causes roseola infantum; high rever, subsequent rash spread through contact with respiratory secretions or saliva many bone marrow transplant recipients suffer form HHV-6B viremia after transplantation some researchers believe HHV-6A virus lies dormant for years and may be associated with multiple sclerosis later in life

Question 32

EBV

Answer 32

Causes MONO in BV and HHV-8 family: oncogenic viruses sore throat, enlarged lymph nodes more serious in immuncompormised patients, tumor formation formed from continues proliferation of infected B cells

Question 33

Kaposi Sarcoma characteristic rx pathogen

Answer 33

c: angiogenic tumor of blood vessle walls rx: most commonly seen in immmunocompromised patiens and AIDS patients P: caused by HHV-8, forming dark or purple skin lesions

Question 34

Measles

Answer 34

highly contagious disease caused by member of paramyxoviridae family transmission through respiratory droplets Koplik spots are red pached with grain-lik centers along gum line Rash on hairline to face, trunk, extremeties complications inclue: bacterial disease in respiraoty tisssue, panancephalitis

Question 35

Rubella (german measles) Pathogen transmission symptoms

Answer 35

Caused by virus of Togaviridae family transmitted through respiratoy droplets or contact symptoms include fever, pale pink musculopapular rash recovery prompt, relapses can occur congenital rubells occurs when fetus is affected through placenta and children may be born with problems in eye, ear, heart

Question 36

Fifth Disease

Answer 36

caused by member of parvoviridae transmitted through respiratory droplets fiery red rash on cheeks, ears, and trunks adults can eperience symptoms similary to those of RA

Question 37

HPV

Answer 37

common warts are benign skin growths results in a specific strain of HPS Planta warts- on soles of feet transmitted by contact with affected person of contaminated object

Question 38

Poxviruses

Answer 38

small pox (variola) contagious and sometime fata macules appear and become papules and fluid-filled vesicles focal infection of skin, intestines, lungs, kidneys , and brain

Question 39

Dermatophytosis

Answer 39

fungal infecition of skin, hair and nails

Question 40

Sporotrichosis

Answer 40

fungus sporothrix schenkii forms subcutaneous lesions

Question 41

Leishmania

Answer 41

fungus that can cause cutaneous infections

Question 42

Dermatophytes

Answer 42

group of fungi that require keratin form growth cause cutaneous mycoses cause dermatophytosis as a disease clinical presentation: classic appearance surrounded by red, scaly, elevated border

Question 43

tinea capitis

Answer 43

dermatophyte ringworm of scalp: of skin and hair follicle

Question 44

tinea coporus

Answer 44

dermatophytosis of skin on trunks and extremity

Question 45

tinea cruris

Answer 45

dermatophytosis of prxomimal thigh/ buttocks

Question 46

Tines Pedis

Answer 46

dermatophytosis of foot

Question 47

Tinea unguium

Answer 47

infection of nail, dermatophyte

Question 48

defense mechanism of eye

Answer 48

tears and conjuctiva

Question 49

eye may contain endogenous microbiota

Answer 49

staphylococci, streptococci, cutibacterium

Question 50

trachoma

Answer 50

sexually transmitted bacterial eye infection

Question 51

gonorrhea

Answer 51

bacterial eye infection, sexually transmitted

Question 52

Viral and parasite eye infections involve conjuctiva or cornea

Answer 52

viral pink eye acute conjuctivitis pharyngoconjunctival fever acanthamoeba keratitis ochocerciasis (river blindness) - intermediate host is fly - definitive host is person