Cutaneous Fungi And Ectoparasites Flashcards
Dermatophytes include
Microsporum, trichophyton and epidermophyton species
Are all fungi
Ectoparasites include
Scabies and lice, bedbugs, mites, ticks
Are Arthropoda that love outside the skin in superifical epidermis
Body lice can transmit what infections?
Epidemic typhus
Relapsing borrelia recurrentis fever
- incubation 3-10 days with sudden onset fever
- presents with 3-10 secondary fever attacks after the first onset one
- febrile for 5 days, a febrile for 10 days, febrile for 5 days, etc.
Trench fever
- caused by B. Quintana
- bacteria replicate in RES cells
- presents with severe headache sudden fever and rash/arthralgia/myalgia throughout long bones and extremities
- 5 day intestine fever also
**associated with crowded living and poor hygiene
Rickettsia prowazekii vs rickettsia typhi
Prowazekii
- vectored by human lice
- casues fatal EPIDEMIC typhus
- more serous
Typhi
- vectored by nay fleas
- causes mild ENDEMIC typhus
- *both show**
- fever chills
- malaise
- rashes
rash is different from Rocky Mountain spotted fever since it spars the palms and soles and begins on the trunk and spreads outward
Pubic lice is casued by what?
Phthirus pubis
- easily treatable and extremely pruritic
- is a crab louse (NOT head louse)
Scabies
Caused by sarcoptes scabies
Embed eggs in the stratum corneum and are very pruritic
- usually between fingers and toes
Eggs take 2-3 days to hatch and nymphs can stay inside for 2 weeks until they become adult size
Fungi walls are made of what that is unique to them only ?
Chitin
What agar do dermatophytes grow on?
Sabouraud dextrose agar
- use KOPH preps to stain blue
Tinea capitis
Scalp ringworm
Symptoms
- pruritus
- alopecia
- scaling of skin
- lymphadenopathy
Tinea corporis
Ringworm of the body
Shows enlarging rings with a central clearing (associated with this)
- scaly erythemaouts as well and very pruritic
Often zoonotic causes
Tinea cruris
“Jock itch”
Found in the inguinal area and is prutiritc
- lacks central clearing seen in tinea corporis
Tinea pedis
“Athletes foot”
3 sub presentations
- between toes (interdigital)
- moccasin type
- vesicular type
Tines unguium
“Onchomycosis”
Occurs form untreated tinea pedis
Tinea versicolor
“Pityriasis”
- caused by malassezia or pityrosporum not dermatophytes
Not as pruritic, but shows hypopigmentation rather than hyperpigmentation**
under microscope the species has a “spaghetti and meatballs” appearance
Sporothrix schenckii
“Rose gardeners disease”
- sporotrichosis fungi that is brought into skin via thorn punctures
Generates pustules or ulcers in a chain like apperance along draining lymphatics
looks like “cigar-shaped” yeast on imaging
