13 - Bites, Stings, Infestations Flashcards
What is human scabies?
Highly contagious dz caused by sarcoptes scabiei mite
S/s of human scabies?
Bruising/excoriations from itching/scratching
Kids - vesicles
Secondary staph impetigo
Human scabies may be mistaken for?
May be mistaken for atopic dermatitis
Etiology of human scabies?
Mite
Skin to skin contact
Crowded living conditions
Can live for several days outside skin
Who doesnt get scabies?
DPP rarely acquire it
We dont know why
Common locations of scabies infection?
Slide 5
Arm pits Belt line Groin Wrist Finger webbing Anus Knees Heels of Feet
Morphology of scabies?
Create a burrow (tunnel) - best seen where they cant scratch Itching (at night) 1st lesion is usually destroyed by scratching Secondary lesions - pinpoint erosions (from scratching)
Describe human scabies lesions?
Burrows 2-15mm long
Pink/white
Slightly elevated
Mite - black dot
MC location
- finger webws
- writs
- sides of hands/feet
- penis
- buttocks
- scrotum
- palms/soles (infants)
Diagnosis of scabies?
Clinical
Touch the burrow w a felt tipped pen and it will suck up ink
Deroof burrow #15 blade and transfer to slide w immersion oil
- mites, eggs, feces
Tx for scabies?
Permethrin 5%
Lindane (1% kwell)
Ivermectin
Treat family members
HC in Eucerin for inflammation
How long does itching last w scabies?
Continues until mite, eggs, and stool are expholiated
Tx w antihistamine prn
Lindane 1% (kwell) rundown
Chemical pesticide Toxic NOT FOR KIDS <2 NOT FOR PREGGO Pretreat w steroids Apply to dry skin Sleep nude (occlusion) Only for confirmed infestation
Ivermectin (stromectrol) basics?
Vet medicine
Human dose 12mg PO on day 1 and 8
What types of scabies get ivermectin?
Norwegian scabies HIV Institutionalized Nursing home Tx failure
Whats the deal with crusted Norwegian scabies?
HIV pts
Its a variant of scabies but
- w 1000’s of mites
- not much itch
- highly contageous
- scaly
- significant crusts
Where does crusted norwegian scabies like to go?
Primarily hands and face
Pediculosis is aka?
Lice
Clinical manifestations of pediculosis?
Pediculosis capitis - hairPediculosis corpis - body Pediculosis pubis (crabs)
How to ID lice?
See them in seams of clothes
Woods lights - yellow-green to blue-green
Pediculosis etiology
Skin to skin contact
Formite to skin
Sex
Head like rare in DPP
Pediculosis management?
Clean/burn clothes
Clotes/formites bugs may survive 10 days - 3 weeks off a host
Body lice concerns?
Can carry typhus and trench fever
Pediculosis txt?
Body lice
- permethrin (elimite)
- (head to toe, leave on 10 min)
Head lice
- permetherin shampoo
- (10 min)
- coat eyelashes w vaseline
- wash w body shampoo TID x 5 days
Crabs (P. Pubis)
- permethrin shampoo (for body)
- comb/shave pubic hair
- check for STI
All types of pediculosis need?
Tx close contacts
Retreat q 7-10 days
Wash/burn everything
- may be able to use dyer on high
MC skin disease among travelers to tropical countries?
Cutaneous larva migrans
Aka creeping eruption
Cutaneous larva migrans are commonly seen?
Back buttocks, foot/hand
In the SE Us
Etiology of cutaneous larva migrans?
Accidental invasion of hookworms
- burrows 1-2mm qd
- long serpiginous lesions
- larva eventually dies
Cutaneous larva migrans management?
Topical
- steroid to decrease inflammation
Oral (sever cases)
- ivermectin repeat in 1-2 wks
- albendazole x 3-7 days
Its self limiting though so dont go crazy
Management of fleas?
Symptomatic tx - antihistamine - topical abx - topical steroids Get rid of fleas - treat pets - bedding
Presentation of bed bugs
On exposed skin
Rows of 3-5 bites
Adenopathy and fever (numerous bites)
Look for bugs at night
Etiology of bed bugs?
Cimex lectularius
Management of bed bugs?
Get rid of bugs
Symptomatic tx
- antihistamines
- topical preps PRN
What are chiggers?
Mite that attaches to human from tall grass
Presentation of chiggers?
Legs and belt line (or other ares of constriction)
Intense itch
FB reaction
Persisten
Management of chiggers?
OTC chigger meds
Nail polish
Chig-a-way
Treat symptoms
Unlike the previous stuff., fire ants?
Sting (not a bite)
W immediate pain
Also prone to anaphylaxis
- wasps and bees are their cousins
Presentation of fire ant sting?
Wheal -> vesicle -> pustule
Tx for fire ant sting?
Symptomatic
- cool compress
- sarna lotion (OTC anti-itch)
- antihistamine
- steroids (if severe)
Presentation of cat scratch fever?
Exposure to cats - scratch or bite - fleas (may spread it) Malaise Low grade fever Ocular manifestations
More common in kids/teens
Morphology of cat scratch fever?
Single red papule (non-pruritic) Evolve to vesicle filled w sterile fluid Spread to node-enlarged Tender and firm May suppurate
Distribution of cat scratch disease?
Usually extremities but anywhere you got scratched/bit
Cat scratch fever diagnosis
Primary lesion
- papule/pustule site in the presence of LAD and H/O cats
Causative agent
- bartonella henselas
Lymph node biopsy
- small plepmorphic bacilli
- via warthin-starry silver strain
Tx for cat scratch disease?
Mild
- spontaneous resolution in 4-6 wks
Severe
- Antibiotic therapy
- azithromycin (z pack)
- erythromycin
- doxy
Suppurative node can be drained
- needle aspiration
What sound do porcupines make when they kiss?
ouch!
