Microbial disease of the skin and eyes Flashcards
1
Q
Skin
A
- Epidermis
- Dermis
- Mucous membrane
2
Q
Epidermis
A
- Thin outer layer
- waterproof
- Stratum corneum
- keratin
3
Q
Dermis
A
- thick inner layer of the skin
- many connective tissues
- hair follicles, sweat glands , and oil glands
- mircoorganisms can enter the body via these - Perspiration
- Sebum
4
Q
Perspiration
A
- Provide moisture and some nurtients for microbial growth
- contains salt
5
Q
Sebum
A
- secreted by oil glands
- mix of lipids, proteins and salts
- prevents hair and skin from drying out
6
Q
Mucous membrane
A
- lines the body opengsing and open to the exterior
- gastrointestinal, respiratory, urinary and genital tract
- outer protective barrier
- tighly packed epitheial tissue
- often acidic
- folded
7
Q
Normal microbiota
A
- resistant to drying and high salt concentration
- gram pos. cocci
- staphylocci and micrococci
yeast causes dandruff
- staphylocci and micrococci
8
Q
Microbial disease of the skin
A
- exanthem
- skin rash from disease
- a breakout
- Enanthem
- rash on the mucous membrane from disease
9
Q
Types of skin lesions
A
- Vesicles
- small, fluid filled lesion
- Bullae
- vesicle larger than 1cam in diameter
- Macules
- flat, reddened lesion - paplules
- raised lesions
10
Q
Staphylococcal skin infections
A
- gram pos.
- coagulase
- enzymes that clot fibrin in the blood
- used to identify staphylococci
S. epidermidis
- used to identify staphylococci
- 90% of normal skin mircobiota
- healthcare associated infection
- biofilm
- coagulase- neg
S. aurease
- 20% of nasal pathway- coagulase pos.
- avoids host defenses in the skin
- enzymes that clot fibrin in the blood
11
Q
Staphylococcal skin infections PT.2
A
- Folliculitis:
- infection of hair follicles
- Sty
- infection of the eyelash
- Furuncle (boil)
- type of abscess, localized region of pus in inflamed tissue - Carbuncle
- damage and inflammatior of deep tissue from spreading furuncle - Impetigo
- crusting sores spread by autoinoculation
12
Q
Streptococcal skin infections
A
- gram pos. cocci in chains
- produce hemolysins that lyse red blood cells
- beta-hemolytic streptococci often casue disease
- group A- T based on their antigenic cell wall
Group A strep. (GAS)- Streptococcus pyogenes
- produces virulence factors
- streptolysins: lyse RBCs
- M proteins: allow adherence and immune system avoidance
- produces virulence factors
- Streptococcus pyogenes
- Erysipelas
- infection of the dermis layer
- cause by local tissue destruction and sepsis
- S. pyogenes
Necrotizing fasciitis- flesh eating disease
- exotoxin A acts as a superantigen
13
Q
Acne
A
- caused by blockage of hair follicles and sebum
- comedonal (mild) ance
- topical formation
- inflammatory (moderate) acne
- caused by propionbacterium acnes
- metabolizes sebum and fatty acids produce inflammatory response- treated w/ antibiotics and benzoyl peroxide
- Codular cystic (severe) acne
- inflamed lesion w/ pus deep in the skin
14
Q
Viral skin disease
A
- Warts
- Papillomas: small skin growths
- from contact
- HPV
- treated w/ cryothearpy, electrodesiccation or salicylic acid
- Smallpox
- Orthropoxvirus
- 2 forms Variola major 20% mortality
- Variola minor less than 1% - spread via respiratory and moves into the bloodstream and infects skin
- eradicate by vaccines
- Chickenpox
- Varicella
- human herpesvirus 3
- via respiratory route - pus filled vesicles
- Reye’s disease
- severe complication of chickenspox
- vomiting and brain dysfunction
- preventable by vaccine
15
Q
Shingles
A
- herpes zoter
-reactivation of latent aricella -zoter viruse moves along peripheral nerves - affects cutaneous sensory nerves
- limited to 1 side of the body
- preventable by vaccine
16
Q
Herpese simplex
A
- Human herpes 1 and 2
HSV 1: oral or respiratory route
HSV-2: sexually - cold sores or fever blisters
-HSV-1
- latent in trigenminal nerve ganglia
- triggered by sun, stress or hormonal changes
- HSV-2
- laten in sacral nerver ganglia near the spine
- herpes gladiatorum: vesciles on skin
- herpetic whitlow: vesicles on fingers
- herpes encephalitis: virus spreads to the brain
- treatment: acyclovir
17
Q
Measles (rubeola)
A
- viral spread via respiratory route
- cold like sympotms
- Prevented by vaccine
18
Q
Rubella
A
- german measles
- rubella virus
- via respiratory route
- congential rubella syndrom
- fetal damage, deafness, hear defects, mental retardation
- pervented by vaccine
- not recc. for pregnant women
19
Q
Fungal disease of the skin and nails
A
- Mycosis: fungal infection of the body
Cutaneous mycoses - Dermatomycoses
- tinea captitis: scalp ringworm
- tinea cruris: jock itch
- tinea pedis: atheles foot
- tinea unguium: ringworms of the nails
20
Q
Subcutaneous mycoses
A
- More serious
- penetrated stratum corneum
inhabits the soil - Sportotrichosis
- forms small uler
- treated w/ postassium iodide
21
Q
Candidiasis
A
- over growth of yeast
- genitourinary tract and mouth
- thrush: oral cavity
- vagnial yeast infection: infection of the vagina
- cutaneous candidiasis: infection of skin and nail
22
Q
pediculosis (lice)
A
- feeds on blood of the host
- lays eggs on the hair and attach to chafts
- topical treatments
23
Q
Inflammation of the eye membrane
A
- conjunctiva: inflammation
- haemophilus influenzae
- and adenoviruses
- can be assoicated w/ unsanitary lenses
24
Q
ophthlmia
A
- neisseria gonorrhoease
- large amount of pus formas
- ulceration of corneas
- newborns through birth passageway
- antibiotics for newborns eye
25
Trachoma
- Chlymadia trachmatis
- leading cause of blindness in the world
- hand contact of flies
- permanent scarring and abraded cornea
- chronically closed
26
Keratitis
- inflammation of the cornea
- bacterial in the US
- Fusarium and Aspergillus ( Africa and Asia)
Herpetic keratitis
- casued by HSV- 1
- Infects cornea and may cause blindness
- treated with trifluridine
Acanthamoeba Keratitis
- ameba found in freshwater, tap water, hot tubes and soil
- mild inflammation to severe pain
