Skin Bugs Flashcards
American trypanosomias is caused by>
Trypanosomiasis Cruzi
African trypanosomiasis is caused by
T. Brucei
In what regions is American trypanosomiasis endemic
Central and South America
Transmission of T. Cruzi occurs through
Reduvid bugs and infected blood
What is American trypanosomiasis?
A serious systemic disease that affects primarily the autonomic nervous system, the heart, and GI tract
What is a Romana sign?
edema of the periocular tissue due to entry through the conjunctiva
Know the life cycle of the disease
ok
What characterizes the acute phase of Chagras disease
Localized erythema, swelling in regional lymph nodes
Romana sign- painless edema of papebrae occurs in 80% of infected bites
Fever, malaise, anorexia, edema of face and lower extremities
Chronic phase of Chagras disease
Occurs many years after the acute phase
Most prominent involvement is the heart.
You get cardiac failure, cardiomegally, arrythmias, etc.
In the GI you get megacolon and megaesophagus.
Chagas disease treatment?
Nifurtimox and Benzimidazole
What organism causes African trypanosomiasis?
In west africa it is T. brucei gambiense and in East Africa it is T. Brucie rhodiense
African trypanosomiasis is carried by what bug
tsetse fly
Clinical presentation of African trypanosomiasis
You get a trypanosome chancre, enlargement of lymph nodes, neurologic manifestations, irritability, personality changes, day time somnolence, insomnia in some
What is onchocerciasis?
River blindness. Predominantly effects cutaneous and ocular tissue
What causes onchocerciassis?
Onchocerca vovulus….a nematode
What transmits onchocerca volvulus
Simulium Black Fly. exclusively affects humans living in tropical african belt and South America.
Clinical presentation of onchocerciasis?
Subcutaneous nodules that are located over bony prominences.
Intermittent pruritic dermatitis
Chronic Onchocerciasis: Thickened wrinkled skin with hyperpigmentation (elephant skin)
Microfilariae in conjunctiva move through cornea of posterior and anterior eye chambers causing conjunctivitis, sclerosing keratitis, optic atrophy, glaucoma
Blindness in severe cases.
treatment of onchocerciasis?
Ivermectin, potential nodulectomy
What is the Mazzotti reaction
Immune system goes haywire after treatment. You get fever, chills, feel terrible. Probably due to break up of the organism
Tungiasis is what
an infestation caused by the burrowing flea tunga penetrans
Where is Tungiasis endemic?
central and south america, carribean, Africa, Pakistan, India
Cutaneous Myiasis>
Inhabit skin wounds or burrow into the dermis causing boil like lesions
Bedbugs appearance
flat oval body, red brown in color, about the same size as a tick (you can see them)
Bedbug behavior?
feed at night, hide in cracks and crevices during day
Pediculosis capitis>
head lice
pediculosis corporis
body lice
phthiriasis
pubic lice
Body lice
hide in seams of clothing, nits attach to clothing, pruritis may be the only symptom, red bumps under arms, upper shoulders, neck
Maculae Cerulae
Bluish/brown hemosidering laden molecules (intradermal hemorrhage at lice feeding sites.
Body lice can be a vector for
Epidemic Typhus, Trench Fever, Relapsing Fever
Pubic lice (crabs)
Generally transmitted through sexual contact. May also effect eyebrows, eyelashes, hair, scalp
May also cause maculae cerulae
true. They are bluish brown hemosiddering laden molecules
Look at scabies in pwrpt
ok
Most common clinical presentation
severe pruritis, often at night
Burrowing is the primary lesion
Where are scabies lesions most commonly found
interdigital web, wrist flexor surface, elbows, penis, scrotum, belt line
Infants can have scabies where?
head and face
How do you diagnose scabies>
Skin scraping. scrape hard and deep Look for: -the mite itself -scybala (feces) - eggs
Spiders to worry about in the US
Brown recluse, hobo spider, black widow spider
All spiders have 8 legs, 4-6 pairs of eyes, 2 body sections (cephalothorax) and abdomen
true
Brown recluse hotspot
Oklahoma, Arkansas, Missouri, Tennessee
Brown recluse bite clinical presentation
vary from mild to ulcerative necrosis (25%), bite often appears with central mottling and blister. surrounded by halo and redness
Systemic reactions from brown recluse bites?
Shock, hemolysis, renal insufficiency and DIC especially
What is the major toxin released by brown recluses
sphingomyelinase D, it interacts with serum amyloid protein, Hyaluronidase allows eschar to spread
Brown recluse spider bite treatment
- Rest, Ice, Elevation
- Interdermal injection of polyclonal anti-loxoxceles Fab fragments
- hyperbaric oxygen
- Dapsone
- Prednisone
Hobo spider
lives in dark, moist areas, Large and hairy, very aggressive
Hobo spiders are found mostly where?
Pacific Northwest.
Clinical presentation of Hobo spider bite
not painful, necrosis ensues and can lead to amputation
Systemic symptoms include headache, nausea, weakness
Hemolysis and thrombocytopenia have been reported
Black widow clinical presentation
local redness and sweating at wound site
Venom in black widow bites causes depletion of acetylcholine and release of catecholamines at nerve endings.
Muscle Spasms, ABDOMINAL PAIN, headache, paresthsias, nausea, vomitting
Treatment for black widow bites
IV calcium gluconate
