Infestations and Bites - Patel Flashcards
who does scabies affect? who does it more commonly affect?
Sarcoptes scabiei (scabies) affects patients of all ages and all scoioeconomic classes, although it is more common in women and children
How does one contract a scabies infection?
most infections occur from direct contact w/ an infected individual; fomites can transmit infection
Who is at especially increased risk of contracting a Scabies infection?
those in group settings (nursing homes) or in an immunocompromised state
in Scabies, what is the time from initial infestation to symptoms
3-4 weeks once sensitizied to the mite, re-infestation results in symptoms within 1-2 days
Where do papules commonly occur on the body in Scabies?
axillae, breasts, umbilicus, penis, scrotum, finger webs and wrists
Scalp and head scabies infection is more common in what subset of patients?
Infants, elderly, and immunosuppressed
what is the hallmark clinical feature, symptom, seen in Scabies (not sign)
itching at night
what is pathognomonic for scabies - this is $$$
Burrows - linear markings in the skin due to the mvmt of the mite, they are 1-10 mm in length
where do you most commonly find the burrows seen in scabies
interdigitial spaces, wrists, and elbows
what do you do in a patient that you suspect has scabies - be specific
skin scraping - mineral oil preparation use a 15-blade scalpel and scrape a burrow on the skin - scraped material is then placed on a slide and a drop of mineral oil is added - a cover slip is placed on top and you look through a microscope - look for the scabies mite, eggs, or scybala (feces)
what is crusted scabies also called and who is most at risk of developing
hyperkeratotic (thickening of epidermis) scabies. hence the term “crusted”
immunosuppressed or neurologically impaired individuals are at increased risk
what is the presentation of crusted scabies
thick, scaly, white-gray plaques with minimal pruritis
where on the body does crusted scabies often present
scalp, face, back, buttocks, feet
what is the importance of fissures in crusted scabies
provide an entry for bacteria leading to increased risk of sepsis and death
what happens to immunocompetent individuals who come in contact w/ crusted scabies
they develop typical scabies
what is a good differential finding in crusted scabies to help you diff from typical scabies - this is symptom of pt
pts do not complain of itching
In general, what is the treatment strategy for scabies
two pronged approach both the pt and the environment must be treated
what is the specific treatment strategy for the patient in treating scabies (the first prong)
two topical treatments separated one week apart with a prescription anti-scabietic medication
what is “post-scabietic” pruritis or dermatitis and the significance?
itch and lesions can persisit for 2-4 weeks after successful tx - this is not tx failure, rather it represents the body’s response to dead mites
what is the specific 2nd prong of treatment for scabies, how you treat the env
washing all clothing and linens within the last week in hot water and drying on high heat. items that cannot be washed, seal items in bags for 3 days alternatively, just burn it all. burn it all to the fucking ground
for scabies treatment, is isolation from other ppl necessary or not? why or why not?
isolation is unnecessary - the scabies mites cannot jump or fly, and can survive for only approx 72 hours away from skin
what is the first line tx medication for scabies? what pt populations can you use this in?
5% permethrin cream pts older than 2 mos age DO NOT use in pregnancy
what is treatment for crusted scabies?
combination therapy multiple doses of oral ivermectin topical permethrin - freq more than 2 treatments are required
do crusted scabies pts need to be isolated?
yes - due to the high mite burden
what is the organism name of lice
Pediculosis
what is the name of head louse
Pediculus humanus var. capitis
what is the name of body louse
Pediculus humanus var. corporis
what is the name of pubic lice AKA crabs
Phthirus pubis And that’s the second time I got crabs…
who does lice affect? who is lice less common in
lice affects all ethnic and socioeconomic gorups, usually SCHOOL AGED CHILDREN, but is less common in African Americans (that nappy hair tho)
female adult lice lay eggs known as what? and where do they lay them?
nits they lay the nits at the base of the hair where it meets the scalp
How can you estimate the duration of a lice infestation?
the nits (eggs) remain associated with the hair near the scalp, for warmth and moisture, but as the hair grows, the nit goes with it so, since hair grows at a rate of 1 cm per month, the duration of infestation is estimated by the distance of the nit from the scalp
what are 3 common clinical features of a lice infestation
scalp pruritus
posterial cervical LAD
dermatitis - posterior neck
what is easier to see on exam, nits or lice?
nits - live lice scurry away from light
where are the most common sites to find nits on the head?
retroauricular and occipital scalp
what is the diagnostic criteria for pediculosis capitis? regarding nits, and why
adult lice and/or nits within 1 cm of the scalp are dx
nits within 1 cm of scalp are viable
what must you distinguish nits in head lice from? and how do you tell the difference
must distinguish ntis from hair casts hair casts encircle the hair shaft and move freely in contrast to the nit which is cemented on the hair
what is the first line tx for head lice when resistance is not sucpected
OTC permethrin 1% or pyrethrins
what is 1st line tx for head lice when resistance fo permethrin or pyrethrins is documented
malathion 0.5%
what is key part of the tx strategy for head lice (pediculosis capitis)
prudent to re-treat with topical therapies 7-9 days after initial therapy to kill newly hatched lice
what is the East TN method of treating head lice
occlusive methods - suffocate head lice using pertoleum jelly (lube) and mayonnaise official study results have been variable epidemiologic studies say this shit works great, and it has the added bonus of attracting the ladies
where do body lice infest
back, neck, shoulders, waist
where do crab lice infest
lower abdomen, thighs, and in the pubic area
what micro bug causes Lyme dz
Borrelia
what kind of micro bug is Borrelia, and what insect transmits it
Borrelia is a spirochete, transmitted by the Ixodes tick (deer tick)
where (regionally) do the majority of cases of Lyme dz occur?
NE United States and in Minnesota and Wisconsin
what is the initial presenting cutaneous clinical feature of Lyme dz
erythema migrans 3-15 cm or larger annular plaque about a week after a bite
what is the appearance of typical erythema migrans?
annular, large plaque, central bite mark area thingy, clearing in the middle
what are the 3 options for early treatment of Lyme dz
doxycyline, amoxicillin or cefuroximine
what is the most common type of bed bugs (name of the micro shit)
Cimex lectularius
are bed bugs day walkers or night hawks?
they stay hidden during the day and feed at night
What is the colloquial term for the appearance of bed bug bites
“breakfast, lunch and dinner” bites may be multiple in a linear array
what are the fancy derm words we use to describe the appearance of the bed bug bites
edematous papules scattered over the body, some are excoriated they are pruritic
what is the tx of bed bugs?
bites will typically resolve w/in 1-2 weeks
symptom relief - potent topical steroids and antihistamines
ultimate treatment requries detection and eradication of the household infestation
