Flashcards in Microbiology Deck (55):
What is colonization?
presence of bacteria in insufficient numbers to cause infection
How do normal cutaneous flora prevent infection from pathogenic organisms?
through hydrolysis of skin lipids found in sebum to free FAs, which are toxic to some bacteria
What causes non-bullous impetigo?
staph aureus (and staph pyogenes)
What causes bullous impetigo?
staph aureus phage II, type 71
What structural component does bullous impetigo interrupt?
How do you treat impetigo?
How do you diagnose impetigo?
clinically and with a superficial wound culture
Describe common features of Ecthyma.
Typically related to trauma
pustules and vesicles followed by ulcerations with thick adherent crust
Heals with scarring
How do you diagnose ecthyma?
How do you treat ecthyma?
What causes ecthyma?
steph pyogens or staph aureus
What is an abscess?
a collection of pus with surrounding fibrous reaction
What is a furuncle?
an abscess that involves a hair follicle
What is a carbuncle?
A collection of furuncles
What may mimic an abscess?
A sterile, inflamed ruptured cyst
How are abscesses treated?
warm compress, incision and drainage, and possibly antibiotics
How do you diagnose an abscess?
clinical appearance and culture of purulent exudate
What causes erysipelas?
what are some common features of erysipelas?
commonly affects elderly patients
Erythematous plaque with sharply demarcated border
face and lower extremities often involved
lymphatic destruction may result in recurrent infections
what causes Erythrasma?
What pathology reveals coral red fluoreseence in the wood's lamp?
What is the treatment for erythrasma?
topical antibiotics or antifungals
What is the presentation of erythrasma?
well-defined erythematous patches with fine scale
involves axillae, inguinal folds, gluteal cleft and other sites of moist occlusion
What dermatophytes cause tinea?
trichophyton, epidermophyton, and microsporum
Tinea cruris spares what?
How is tinea diagnosed?
KOH revels branching hyphae (septate)
How is tinea treated?
topical antifungals--> clotimazole and terbinafine
What causes Pityriasis (tinea) versicolor?
How do you diagnose Pityriasis versicolor?
KOH examination that revelas short hyphae and clusters of spores
How do you treat tinea versicolor?
topical antifungals, oral antifungals (sweat) and wash skin twice monthly with selenium sulfide to reduce reoccurrence risk
what causes cutaneous candidiasis?
How do you treat cutaneous candidiasis?
topical antifungals (clotrimazole and nystatin) and zinc oxide paste
Describe common features of Cutaneous candidiasis?
Often seen in skin folds
Erythematous patches with satellite papules and pustules
may have foul odor
may involve the scrotum
What pathology causes diaper dermatitis?
What causes seborrheic Dermatitis?
What is the treatment for seborrheic dermatitis?
topical antifungals, low potency steriods, and anti seborrheic shampoos
What are some common features of seborrheic dermatitis>
yellow, greasy scale with or without underlying erythema
occurs on scalp, glabella, alar creases, chin, chest and inguinal folds
oral disease is cause by HSV1 or 2?
How is Herpes simplex infection diagnosed?
clinical presentation, PCR and Tzanck prep (multinucleated giant cells)
What is erythema multiforme (EM)?
recurrent, self-limited eruption of the skin and/or oral mucosa
reaction to an underlying HSV, but HSV is not present on skin
Presents with targetoid macules
Those with Varcella Zoster are at risk for what other pathology?
How is varicella zoster diagnosed?
What is the treatment for Varicella Zoster?
antivirals and VZV vaccine
What part of the epidermis does HPV effect?
What are the warts called that affect the genitals?
What subtypes of HPV carry a risk for cervical cancer?
16, 18, 33, and 35
pouring what over warts may improve detection?
What are treatments for warts?
salicyclic acid, cryotherapy, immunotherapy, electrodessication and curettage, laser, and vaccine
How do you treat Molluscum Contagiosum?
cryotherapy, curettage, immunotherapy or it resolves spontaneously
What causes Erythema Infectiosum (fifth disease)?
How is erythema infectiosum spread?
through respiratory secretions
Where does the sarcopetes scabei mite live?
the stratum corneum
how does scabies present?
itense itching, inflammatory papules, vesicles and burrows (linear tracks)
What is the treatment for scabies?
topical antiscabetics (permethrin 5% cream)