skin infections, envenomations, neoplasms

anaphylaxis treatment

SQ epinephrine hydrochloride 0.3mL of 1:1000 dilution and repeat q20-30 min PRN

anaphylaxis symptoms

wheezing, shortness of breath, trouble breathing, oral swelling, N/V, diarrhea, headache, hypotension, tachycardia, shock

strings clinical presentation

immediate burning, pain, itching, erythema, swelling, induration (hardening), wheals, sterile pustule, maybe stinger present

black widow spider characteristics

black with red on the body

brown recluse spider characteristics

brown, violin shaped

black widow spider bite clinical presentation

mildly painful target lesion bite reaction, abdominal pain, hypertension, muscle pain/spasms/rigidity, irritability, agitation

brown recluse spider bite clinical presentation

localized hive-like reaction with mild redness/swelling

can progress to necrosis and hemolytic reactions (rare)

fever, chills, N/V, weakness, muscle pain within 12-24 hours

scorpion sting clinical presentation

muscle cramps and convulsions, twitching, jerking, hypertension, pulmonary edema

wasp/bee sting treatment

remove stinger ASAP

clean/disinfect

ice pack

elevate

analgesic

antihistamine

black widow bite treatment

parenteral opioids OR muscle relaxants (NOT both)

calcium gluconate

Latrodectus antivenom

brown recluse bite treatment

oral steroids

early excision (if local necrosis)

dapsone (anti-infective)

colchicine (treats inflammation and pain - normally gout)

scorpion sting treatment

analgesics

antivenom for Centruroides stings

scabies risk factors

crowded living conditions

immunosuppression

scabies normal locations

warm areas, toe/finger webs, periumbilical areas, axilla, wrists, elbows, intergluteal areas, genitalia, buttocks

scabies clinical presentation

burrows/tunnels in epidermis

severe itching that worsens at night

scabies diagnostic

microscopic exam of skin scraping after application of mineral oil to burrow will show mite and mite feces

scabies treatment

topical permethrin if >2 months

sulfur ointment if <2 months

pediculus humanis capitis

head lice

head lice characteristics

eggs at base of hair shaft, move by crawling

phthirus pubis

pubic lice

pediculosis humanus corporis

body lice

body lice characteristics

live/lay eggs on clothes and move to skin to feed

head lice clinical presentation

itching, sensation of something crawling on head, irritable, sleepless, sores from scratching

body lice clinical presentation

intense pruritus, rash from allergic reaction to bites

be concerned for transmitting disease (epidemic typhus)

pubic lice clinical presentation

itching, sores from scratching

lice not as visible

lice treatment

topical permethrin (kills lice, not eggs so may need second treatment)

mechanical removal of lice and eggs (wet combing)

pubic lice treatment

malathion lotion

chigger mites

feed on host skin cells, most active in warm climates and afternoon

attach themselves to hair follicle and inject a digestive enzyme that causes intense irritation

chiggers clinical presentation

intense itching, erythematous papules/vesicles

can be washed off at first sign of itching but lesions last

chiggers treatment

vigorous cleaning with soap/water

topical/oral steroids

calamine lotion

oral antihistamines

bed bugs

small ectoparasite that requires a blood meal, nocturnal, attracted to warm bodies, hide around beds, cracks, crevices

bed bugs clinical presentation

pruritic lesions, urticaria, vesicles

commonly around waist, axilla, scalp, face, neck, arms

bed bugs treatment

if symptomatic: topical steroids, antihistamines, cool compresses

treat/clean environment

mammal bite treatment

clean extensively

leave open

update tetanus

rabies prophylaxis

abx

human bite specific treatment

amoxicillin/clavulanate

if PCN allergic: moxifloxacin

snake bite clinical presentation

severe pain, N/V, diarrhea, rapid HR, weak pulse, low BP, disturbed vision, metallic/mint/rubber taste in mouth, increased salivation and sweating, numbness or tingling around face/limbs, muscle twitching

snake bite PE

puncture marks, redness, swelling, bruising, bleeding, bilstering, labored breathing

snake bite treatment

antivenom

jellyfish sting local clinical presentation

linear, red, urticarial lesions, burning, throbbing pain, tentacle prints, skin necrosis if severe

jelly fish stings systemic clinical presentation

local symptoms accompanied by back/chest/abdomen pain, vomiting, sweating, agitation, hypertension, tachycardia, MI, pulmonary edema, intracranial hemorrhage, anaphylaxis, cardiac arrest

local jellyfish sting treatment

remove tentacle

rinse site with seawater

hot water immersion/hot pack

vinegar

systemic jellyfish sting treatment

ABCs

antivenin for C fleckeri stings

tentacle removal - apply venous-lymphatic constriction bandage proximal to wound site

vinegar

cold therapy

MRSA risk factors

hospitalization, LTC, incarceration, hemodialysis, recent abx, HIV, IV drug use

cellulitis

diffuse spreading infection of the dermis and subcutaneous tissue due to bacteria

MC caused by GAS or strep pyogenes

sometimes caused by MRSA (often causes abscess)

cellulitis clinical presentation

starts as tender small patch with erythema, swelling, pain

almost always unilateral

lesion expands over hours, onset 6-36h

maybe systemic symptoms: fever, chills, tachycardia, headache, delirium

cellulitis diagnostics

CBC, CMP (leukocytosis), ESR/CRP

skin/wound culture

blood culture

CT to look for osteomyelitis

x-ray to look for FB, gas in soft tissue

cellulitis possible complications

bacteremia, endocarditis, osteomyelitis, sepsis, toxic shock

streaking

traveling infection, often results in/from lymphangitis

mild/moderate cellulitis treatment

supportive/symptomatic management

abx 5-7 days: cephalexin, cefuroxime, cefadroxil

if MRSA risk/PCN allergy: clindamycin, TMP-SMX, or doxycycline

severe cellulitis presentation

fever, chills, tachycardia, rapid symptom progression, unable to tolerate oral therapy

IV abx: vancomycin

change to oral abx if improvement

cellulitis special considerations

extend abx course to 10 days

freshwater exposure: cephalexin, clindamycin

if sewage contamination: metronidazole

saltwater exposure: virbrio spp. (flesh eating) need ciprofloxacin, doxycycline + ceftriaxone, or even surgical debridement

erysipelas

superficial form of cellulitis caused by group-a beta-hemolytic strep or staph

erysipelas clinical presentation

pain, malaise, chills, moderate fever

erysipelas PE

bright red spot that appears then spreads to form tense, sharply demarcated, glistening, smooth, hot plaque

margins advance rapidly over hours/days

maybe vesicles/bullae

erysipelas on feet

can result from tinea pedis with interdigital fissuring

erysipelas diagnostics

CBC (leukocytosis), maybe positive blood cultures

mild erysipelas treatment

dicloxacillin first line

cephalexin, cefuroxime

if MRSA risk/PCN allergy: clindamycin, TMP-SMX, doxycycline

severe erysipelas treatment

IV vancomycin

concern for sepsis

necrotizing fasciitis

rapidly spreading infection leading to extensive necrosis of subcutaneous tissue/fascia

fournier gangrene

genital necrotizing fasciitis

common in diabetics

necrotizing fasciitis risk factors

immunosuppressed, diabetic, neonates/elderly, liver disease pts

MC cause of necrotizing fasciitis

strep pyogenes

other necrotizing fasciitis causes

staph

polymicrobial (e. coli, etc due to stool/urinary proximity)

if water exposure, aeromonas/vibrio

burn pts at risk for pseudomonas

necrotizing fasciitis clinical presentation

similar to severe cellulitis, rapid progression, systemic toxicity, severe pain, multiorgan failure

necrotizing fasciitis diagnostics

CBC, ESR, CRP, CK elevated, CMP abnormal

blood, wound, tissue cultures

CT contrast/MRI

necrotizing fasciitis

broad spectrum abx ASAP! (cover aer/anaerobic)

carbapenem or piperacillin-tazobactam + vancomycin + clindamycin

surgery: early/extensive debridement

abscess

well circumscribed collection of pus

furuncle

acute, deeper than an abscess, around a hair follicle

carbuncle

deeper and more extensive confluence of abscesses

abscess, furuncle, carbuncle treatment

I/D

antibacterial soap

warm compress

mupirocin ointment daily to nares (MRSA)

oral abx: clindamycin, cephalexin, TMP-SMX, doxycyline

if severe: IV vancomycin

packing

impetigo

superficial skin infection MC in kids

impetigo risks

hot/humid environment, poor hygiene, strep/staph carrier, school, daycare, URI

impetigo causes

staph MC in temperate climate

strep MC in tropical areas

impetigo clinical presentation

honey colored crusts

macules, vesicles, bullae, pustules

impetigo treatment

topical mupirocin

oral abx if severe: dicloxacillin, cephalexin

if MRSA: clindamycin, TMP-SMX, doxycycline

children should isolate

hidradenitis suppurativa

chronic inflammatory condition of the hair follicle, relapsing/remitting

inflammation/occlusion of hair follicle leads to rupture of the follicle which then leads to abscess, sinus tracts, scarring

hidradenitis suppurativa clinical presentation

gradual onset of small, red, indurated papules, pustules, nodules with pruritis, burning, pain in mainly the axilla, groin, under breasts

sinus tract formation

lesions usually sterile but can become infected and have drainage (serous, purulent, bloody, malodorous)

scarring

hidradenitis suppurativa treatment

prevention, decrease inflammation

good hygiene, minimize trauma

lifestyle changes: smoking cessation

early hidradenitis suppurativa treatment

topical clindamycin or metronidazole

moderate hidradenitis suppurativa treatment

start with topical

oral abx: tetracycline, doxycycline, minocycline, erythromycin

intralesional corticosteroids

severe hidradenitis suppurativa treatment

tumor necrosis factor-alpha inhibitor (adalimumab)

oral retinoids

surgical excision

HPV warts

common, plantar, genital (condylomata acuminata)

HPV warts info

variable incubation period 2-18 mos

often spontaneous cured

warts clinical presentation

typically painless, papules 2-5mm

can be fixed, mobile, verrucuous, flat, varied in color, grouped, or single

often progresses into dome-shaped hyperkeratotic growth

low risk HPV

HPV 6 and 11

high risk HPV

HPV 16 and 18

warts treatment

debridement

non-genital: cryotherapy, silver nitrate, salicylic acid

genital: topical imiquimod, podofilox, sinecatechins

other wart treatment

duct tape, laser therapy, bleomycin, 5-FU, photodynamic therapy

molluscum contagiosum (poxvirus) transmission

autoinoculation, skin to skin contact

molluscum clinical presentation

1mm-1cm shiny, dome-shaped, firm papules with central area of umbilication/pinpoint, maybe with surrounding erythema/itching

molluscum treatment

can resolve spontaneously, maybe over a year

topical: potassium hydroxyzine, benzoyl peroxide, salicylic acid, tretinoin

primary varicella-zoster

transmitted through respiratory route, replication of virus leads to systemic spread and viremia

recurrent varicella-zoster

infection reactivates, mechanism unknown

virus affects dorsal root ganglia during chickenpox and remains latent

chickenpox

highly contagious varicella virus spread via respiratory droplets or contact with lesions

chickenpox clinical presentation

pruritic rash, centrifugal, papular changing to vesicular then crusts over

“dew drops on a rose petal”

chickenpox diagnostics

PCR scraping

tzanck smear from vesicle base shows multinucleated giant cells

chickenpox treatment

supportive care, isolation

antihistamines

acyclovir only within 24 hours in severe cases

chickenpox possible complications

secondary bacterial infections (staph, GAS)

reye syndrome with aspirin use

epiglottitis, pneumonia, osteomyelitis, meningitis, endocarditis, TSS, encephalitis

congenital malformations in 1st trimester of pregnancy

shingles

tingling, painful eruption of vesicles in unilateral dermatomal distribution that evolves to pustules then crusting over 3-5 days

hutchinson sign

lesions on side of nose indicating potential ophthalmic nerve involvement in shingles