CH7-S1 Infections of the dermatological, skeletal and ophthalamic systems Flashcards
______:
Waterproof protein coating outermost layer
of epidermis
Keratin
_______:
Thin outer portion of skin; vomposed of layers of epithelial cells
Epidermis
_____:
Inner, thick portion of skin; composed mainly of
connective tissue
Dermis
Function of the skin:
- Perspiration (Provides moisture & nutrients for microbial growth, Contains salt that inhibits microorganisms; Lysozyme & antimicrobial peptides break down bacterial cell walls)
- produce sebum (Secreted by oil glands
Mixture of lipids, proteins & salts
Contains fatty acids that inhibit pathogens, and also considered nutritive for many microorganisms) - Mucous membrane (Mucosa) lines the body cavities open to exterior
Properties of Mucous membrane (Mucosa):
Cells secrete mucus
Some cells have cilia
Membrane is often acidic
Often folded to maximize surface area
Areas with ___ have higher population of microbes (e.g. ____, between legs)
moisture, Armpits
Microbes metabolize ____ & contribute to body odor
sweat
Terms describing skin rashes/lesions:
_____: Small, fluid-filled below the epidermis
Vesicles
Terms describing skin rashes/lesions:
_____: Vesicles > 1cm in diameter
Bullae
Terms describing skin rashes/lesions:
_____: Flat, reddened lesions, skin color change
Macules
Terms describing skin rashes/lesions:
_____: Raised lesions (<5mm in diameter)
Papules
Terms describing skin rashes/lesions:
_____: Raised lesions with pus
Pustules
Staphylococci:
Shape: _____
Gram _____ bacteria;
forms irregular clusters like ____
Spherical, positive, grapes
Categorization of Staphylococci can based on ____________
(Coagulase-positive strains
Coagulase-negative strains)
the ability to produce
coagulase (Enzyme that clots fibrin in the blood
_______: Represent 90% of normal skin microbiota, coagulase-___
Pathogenic only when skin barrier is broken; a healthcare-associated pathogens; produces biofilm on catheters
Staphylococcus epidermidis, negative
_______: Carried in the nasal passages of 20% of the population,
coagulase-_____; forms golden-yellow colonies
Staphylococcus aureus, positive
Staphylococcus aureus avoids host defense by:
Secreting a protein to _____ to the infection site on the skin;
Secreting toxins that ____
Secreting proteins to ____
block chemotaxis of neutrophils,
kill phagocytic cells,
neutralize the antimicrobial peptides
Staphylococcus aureus
Produce ____ to cause sepsis or enterotoxins to affect GI tract
damaging toxins
Staphylococcal skin infections
____: Infection of the hair follicles
Folliculitis 毛囊炎
Staphylococcal skin infections
____: Fever, vomiting, shock & organ failure caused by _____ toxin I in blood
Toxic shock syndrome (TSS)
Staphylococcal skin infections
____: Damage and inflammation of deep tissue from a spreading furuncle, usually presented with fever
Carbuncle
Staphylococcal skin infections
____: A type of abscess, localized region of pus surrounded by
inflamed tissue
Furuncle (Boil)
Staphylococcal skin infections
____: Folliculitis of an eyelash
Sty 麥粒腫
Streptococci: Gram ____ cocci in ____
positive, chains
Streptococci produce ____ (a toxin) that lyse red blood cells
hemolysins
Streptococci categorized based on the _____ they produce:
__________
__________
__________
hemolysins
Alpha-hemolytic streptococci
Beta-hemolytic streptococci
Gamma-hemolytic streptococci (Actually non-hemolytic)
Which type of Streptococci often cause disease?
Beta-hemolytic streptococci
Beta-hemolytic streptococci are further differentiated into groups
(Designated A through T) based on the _______ on their cell walls
antigenic carbohydrates
Streptococcus pyogenes belongs to _______
Group A Streptococci
Group A Streptococci (GAS) i.e. Streptococcus pyogenes:
>80 immunological types according to the M protein
;produce virulence factors:
______ that lyse RBCs and are toxic to neutrophils
______ on GAS are located external to the cell wall, allow adherence & immune system avoidance
______ dissolves connective tissue
______ dissolves blood clots
Streptolysins, M proteins, Hyaluronidase, Streptokinase
Group A Streptococci (GAS) i.e. _____ (disease) caused by Streptococcus pyogenes, infects the dermal layer of the skin with well demarcated boundaries
;Forms reddish patches with raised margins
;Cause local tissue destruction, or enters bloodstream to cause sepsis
Erysipelas
_____ is caused by “Flesh-eating bacteria”, belongs to ______ infection
Necrotizing fasciitis 壞死性筋膜炎, streptococcal skin
______ infections
______ aeruginosa: Gram negative, aerobic rod
Produces a bacterial pigment (Pyocyanin) resulting in blue-green pus
Produces exo- and endotoxins
Grows in biofilms, resistant to many antibiotics
Opportunistic in burn patients
Pseudomonads
Pseudomonads ____:
A self-limiting rash associated with swimming pools
dermatitis
Sebum formation is affected by ____ but not _____
hormones, diet
Most common skin disease in humans is ____
Acne
Acnes are formed when skin cells are shed in the hair follicles & combine with sebum -> The
mixture ____
clogs/blocks the follicles
Sebum accumulates leading to whitehead formation 白頭粉刺 (______); blockage protrudes(突顯)
through the skin leading to blackhead 黑頭粉刺 formation (____)
comedos, comedone
Types of acne:
1. ____ Acne
Sebum channels are blocked, easily treated with
topical formations
2. ______ Acne
Caused by Propionibacterium acnes
Metabolizes sebum; fatty acids produce an
inflammatory response
Treated with antibiotics
3. _____ Acne
Inflamed lesions with pus deep in the skin
Comedonal (Mild), Inflammatory (Moderate), Nodular Cystic (Severe)
Impetigo
Also called pyoderma
Superficial bacterial skin infection that is highly _______
Mostly affecting children 2 – 5 years of age
Usually occurs in warm, humid conditions
Easily spread among individuals in close contact
Caused by Staphylococci aureus and Streptococcus pyogenes (Group A Streptococcus GAS)
contagious
The most important causative organism for Impetigo is ________.
Staphylococci aureus
3 types of Impetigo:
1. Nonbullous Impetigo
Most common form
Lesions begin as papules -> Vesicles surrounded by erythema -> Pustules -> Break down to form thick, adherent crusts with
characteristic ____ appearance
Can also spread to surrounding area (autoinoculation)
2. Bullous Impetigo
Seen primarily in young children
____ enlarge to form ____ ____ with clear yellow fluid -> Becomes darker & turbid -> Ruptured leaving a thin brown crust
Fewer lesions than in nonbullous impetigo
S. aureaus that produce exfoliative toxin A -> Loss of cell adhesion @ superficial epidermis
3. ______
Ulcerative form of impetigo -> Lesions into the dermis
Caused by GAS
golden,
Vesicles, flaccid bullae,
Ecthyma
Common sites of Staphylococcal Folliculitis:
Scalp, face, upper trunk, buttocks & legs
Pruritus is common for patient having Staphylococcal folliculitis (T/F)
T (Pruritus is severe itching)
Pseudomonal folliculitis is also known as ______ ; caused by ___, attributed to contact with _____.
Primary occurs on the ______.
Hot tub folliculitis, gram negative pseudomonas aeruginosa, contaminated water (in whirlpools, hot tubs, swimming pool)/ bathing with contaminated sponges/ nylon towels),
Trunk & buttocks
Other gram negative folliculitis is associated with long-term treatment with _____ -> Explosive onset
; ___ as risk factor
oral antibiotics, male sex
_____ (Hansen’s disease) caused by Mycobacterium leprae & Mycobacterium lepromatosis
Acid-fast rod that grows best at 30oC
Grows in peripheral nerves & skin cells
Survives macrophages & invades the _____
Leprosy, myelin sheath
Leprosy is classified as 2 main forms:
1. _____
Loss of sensation in skin areas
2. _____
Disfiguring nodules over the body
Mucous membranes are affected
Tuberculoid (neural),
Lepromatous (Progressive)
_____: fungal infection of the body
Mycosis
Fungal dermatological diseases:
Cutaneous mycoses - dermatomycoses: Tinea cruris (related to DM, obese), Tinea pedis (Athlete’s foot) / Treatment with usually topical drugs: Miconazole, Clotrimazole, Ketoconazole,Terbinafine
Subcutaneous mycoses (more serious) - Sporotrichosis 孢子菌病 Enters a wound to form small ulcer / Treated with potassium iodide
_____ - Thrush C. albicans infection of the oral cavity / Results when antibiotics suppress competing bacteria / a change occurs in the mucosal pH
Fulminating disease in the immunosuppressed
Candidiasis
Viral dermatological diseases
____ (papillomas) - Transmitted via contact / Treated with _____ 冷凍療法, electro-desiccation 電脫水 or salicylic acid 水楊酸
______- Causes pus-filled vesicles -> Formed scabs / Caused by Herpesvirus Varicellovirus 水痘病毒 (A Varicella-zoster 水痘帶狀皰疹 species , human herpesvirus 3) / Transmitted via the _____ route/
Virus becomes ____ in the central nerve ganglia /
Severe complication: ______
Cause vomiting & ________
The use of aspirin in reducing fever in the disease -> Increases risk
_____- Reactivation of the latent varicella-zoster virus that moves along peripheral nerves of the skin
______ - ~90% of the population is infected
______ - Viral disease transmitted by the respiratory route that is highly contagious / Cold-like symptoms, macular rash on body, Koplik’s spot
_____ - Caused by several enteroviruses
Warts, cryotherapy
Chickenpox, respiratory, latent,
Reye’s Syndrome 雷伊綜合症, brain dysfunction,
Shingles
Herpes simplex
Measles
Hand-foot-mouth disease
Viral dermatological diseases
chickenpox (varicella) is caused by:
Herpesvirus Varicellovirus 水痘病毒 (A Varicella-zoster 水痘帶狀皰疹 species , human herpesvirus 3)
Viral dermatological diseases
Shingles (herpes zoster) is the _________________, due to ______,
Vesicles formed in localized area typically about the ____
/ Postherpetic neuralgia 生完蛇神經痛
Antivirals (e.g. ____) can lessen symptoms / Prevention via ______
reactivation of the latent varicella-zoster virus that moves along peripheral nerves of the skin,
stress or lowered immunity,
waist, Acyclovir, shingles vaccine
Viral dermatological diseases
Herpes simplex 單純皰疹
Human herpesvirus 1 (HSV-1): Spread primarily by ___/ respiratory routes / HSV-1 remains latent in ____ nerve ganglia
Human herpesvirus 2 (HSV-2): Spread primarily _____ / HSV-2 remains latent in ______ /
Infection with HSV-2 is more serious (___% fatality rate)
Treated with _____
oral, trigeminal,
sexually, sacral nerve ganglia near the spine, 70, Acyclovir
Viral dermatological diseases
Measles 麻疹 - Viral disease transmitted by the respiratory route that is highly ____/
Cold-like symptoms, macular rash on body, ____ (Red spots on the oral mucosa opposite the molars)
/____ as diagnostic feature
Children under 1 year old do not receive the vaccine (Not effective)
No maternal antibodies as now mothers are usually vaccinated, not recovered from the disease
Child more vulnerable in first year
contagious, Koplik’s spot, Koplik’s spot
Give 2 examples of parasitic dermatological diseases and its treatment
Scabies (Treatment with topical application of permethrin/ Prevent spreading by disinfect clothing in hot water by killing eggs ~60degree Celsius), Pediculosis 蝨病 (Treatment: Permethrin for head lice / Female louse produces eggs / Victim often unaware until itching caused by sensitization to louse saliva - several weeks later)
Infection of the ophthalmic system:
______ - An inflammation of the conjunctiva/ Also called red eye or pinkeye/ Common caused by Haemophilus influenzae (Gram-ve bacteria) and also by adenoviruses (Virus)/ Can be caused by Pseudomonads associated with insanitary contact lens
______ - Caused by the gram-ve bacteria Neisseria gonorrhoeae 淋球菌 / Large amount of pus formed / Transmitted to a newborn’s eyes during passage through the ____
______ - Caused by the bacteria Chlamydia trachomatis 沙眼
衣原體/ Transmitted to a newborn’s eye during passage through the ____
______ - Caused by some serotypes of the gram-ve bacteria Chlamydia trachomatis / Leading cause of blindness worldwide/ Transmitted via ______
______ - Inflammation of the cornea
Conjunctivitis,
ophthalmia neonatorum, birth canal,
Inclusion conjunctivitis, birth canal,
Trachoma, hand contact or flies,
Keratitis 角膜炎
Portal of entry for Conjunctivitis, ophthalmia neonatorum, inclusion conjunctivitis, trachoma, Keratitis:
Conjunctiva
Hematogenous Osteomyelitis
Hematogenous: Caused by microorganisms that seed the bone in the setting of bacteremia
/Risk factors include endocarditis, presence of indwelling intravascular devices (e.g. cardiovascular
devices) or _______
/Clinical manifestations
Dull pain at the involved site
Tenderness, warmth, erythema & swelling
Systemic symptoms (Fever) may also be present
orthopedic hardware
Pyogenic arthritis 化膿性關節炎 also known as septic arthritis -> joint infection/ Bacteremia more likely to localized in a joint with _____/
Clinical manifestation often present acutely with a single swollen
& painful joint, swelling, warmth, restricted movement
Diagnosis based on _____ analysis & culture
pre-existing arthritis, synovial fluid
