Lice, Scabies, Spiders

Question 1

Pediculosis:

• types
• presentation
• dx
• tx

Answer 1

Types:

• capitus - head
• corporis - body

presentation: itching that may lead to cellulitis

dx:
- observation of eggs, nymphs, or mature lice
- woods lamp

tx:
- permethrin (Nix)
- Benzyl Alcohol (Ulesfia)
* treat all persons in contact with this pt

Question 2

Scabies:

• cause
• transmission
• sx
• dx
• tx
• SE of tx

Answer 2

cause: sarcoptes scabiei
transmission: direct contact

sx:
- itching that is worse at night* and with warmth

dx:
- scraping off tiny bit of skin and view under microscope for eggs or mites.

Tx:
-permethrin cream : head to toe for 8-14hrs then wash off.

• Lindane lotion (more neurotoxic than permethrin)
• Oral Ivermectin
• steroids, atarax, or benadryl for itching
• wash clothing, bedding, towels, in hot water.

Permethrin SE;

• itching
• burning
• rash
• redness

Question 3

Spider bites: Widow vs Recluse

• location
• lesion
• genus
• color
• toxic effects

Answer 3

WIdow:
-location: worldwide, garages, boots/gloves outside

• lesion: unremarkable
• genus: latrodectus genus
• color: black
• toxic effects: neurotoxin: alpha latrotoxin. effects neuromuscular transmission

Recluse:
-location: North & South america usually indoors.

• lesion: necrotic
• genus: loxosceles genus
• color: brown
• toxic effects: sphingomyelinase D. Tissue destruction.

Question 4

Spider bites:

-acute presentations

Answer 4

papule

pustules

wheal

*discomfort or prickly sensation that occurs an hour or two after the bite.

Question 5

Widow spiders:

• clinical presentation
• PE findings
• dx
• tx

Answer 5

presentation:
- initially asymptomatic or cause mild paint at the site. (mild envenomation)

-muscle pain is most prominant (extremities, abd, back) (severe envenomation)

• tremor, weakness
• in infants/children: distressed, inconsolable, refusing fluids/food

PE:

• vitals are normal
• muscle rigidity and tenderness adjacent to the bite.
• diaphoresis
• target lesion w/ central punctum

Dx:

• based on sx and hx
• no specific labs; leukocytosis, elevated creatinine, elevated LFT

Tx:

• mild:
• -clean the bite
• -acetaminophen/ibuprofen/hydrocodone
• -muscle relaxants; benzos (valium), methocarbamol (Robaxin)
• tetanus
• mod/severe:
• -local wound care and tetanus
• -parenteral opiods
• -parenteral benzos (lorazepam)
• -antiemetic
• -consider antivenom

Question 6

Brown Recluse:

• typical location of bites
• sx
• PE findings
• dx
• tx

Answer 6

location: upper extremities, thorax, inner thigh

Sx:
Local: 2-8hrs after bite.
-asymptomatic initially
-burning, severe pain at 4hrs

Systemic:

• malaise
• nausea & vomiting
• fever
• myalgias

PE:

• bite is mildy red
• may have fang marks
• *necrotic tissue within 24-48hrs, will have dry eschar, may ulcerate
• blistering

Dx:
-hx and clinical presentation

Tx:

• local wound care
• apply col packs
• maintain part elevated or in neutral position
• NSAIDS or opiods for pain
• tetanus
• Dapsone