BACTERIAL & VIRAL SKIN INFECTIONS Flashcards
may follow impetigo
post-strep glomerulonephritis
IMPETIGO
- high incidence in children
- self limiting (will eventually go away), but if not treated = may last for weeks to months
- Post-strep Glomerulonephritis may follow impetigo**
PE
⦁ nonbullous and/or bullous
⦁ have vesicles and bullae containing clear yellow or slightly turbid fluid without surrounding erythema
⦁ superficial small vesicle or pustules 1-3 cm lesions
⦁ golden-yellow, honey crusted lesions
IMPETIGO TREATMENT
bactroban/mupirocin ointment
- in severe cases = oral antibiotics to cover for staph/MRSA = Bactrim, Clinda or Doxy
MOST RAPIDLY LETHAL FORM OF SEPTIC SHOCK
MENINGOCOCCEMIA
MENINGOCOCCEMIA
- Neisseria Meningitidis
Highest incidence
- between 6 months to 3 years old
- midwinter or early spring
MOST RAPIDLY LETHAL FORM OF SEPTIC SHOCK
Waterhouse–Friderichsen syndrome- septic shock is the result of the adrenal glands being involved; get hemorrhagic adrenal necrosis –> develop acute septic shock
Waterhouse–Friderichsen syndrome- septic shock is the result of the adrenal glands being involved; get hemorrhagic adrenal necrosis –> develop acute septic shock
meningococcemia
physical exam for meningococcemia
⦁ high fever ⦁ tachycardia ⦁ mild hypotension ⦁ signs of meningeal irritation....(photophobia, nuchal rigidity, headache) ⦁ patient appears acutely ill
meningococcemia rash
EARLY EXANTHEM
- occurs soon after onset
- have pink 2-10mm macules/papules that are sparsely distributed on trunk / lower extremities, face, palate, conjunctivae
LATER LESIONS
- petechiae in center of macules
- lesions become hemorrhagic within hours, purpura
- purpura fulminans, hemorrhagic bullae
diagnostics for meningococcemia
⦁ blood cultures
⦁ pus from nodular lesions shows gram negative diplococci
⦁ D-dimers
treatment for meningococcemia
⦁ Cefotaxine (Claforin)
⦁ Ceftriaxone (Rocephin)
⦁ hemodynamic stabilization
cause of meningococcemia
- Neisseria Meningitidis
cause of impetigo
strep or staph or both
cause of bacterial endocarditis
⦁ staph aureus
⦁ strep viridans
risk factors for bacterial endocarditis
elderly
IVDU
prosthetic valves
bacterial endocarditis
have proliferation of microorganisms (staph aureus or strep viridans) on the endocardium of the heart
symptoms of bacterial endocarditis
⦁ fever ⦁ chills ⦁ sweats ⦁ anorexia / weight loss ⦁ malaise
basically all the general symptoms**
PHYSICAL EXAM FOR BACTERIAL ENDOCARDITIS***
⦁ heart murmur
⦁ arterial emboli (may have abdominal pain due to emboli to liver etc)
⦁ splenomegaly (if you feel for it!)
JANEWAY LESIONS
OSSLER’S NODES
BACTERIAL ENDOCARDITIS
janeway lesions = nontender hemorrhagic maculopapular lesions on palms & soles
osler’s nodes = painful red nodules on fingertips
skin lesions with bacterial endocarditis
⦁ Janeway lesions = nontender hemorrhagic maculopapular lesions on palms & soles (thought to be due to miroemboli, or may be autoimmune phenomenon due to reaction to bacteria)
⦁ Osler’s nodes = painful red nodules on fingertips
⦁ Subungual splinter hemorrhages - in order to be pathological = should be off the edge of the nail - in the middle of the nail, but doesn’t go to the tip of the nail
⦁ Petechial lesions = small, non-blanching, reddish-brown macules on extremities, upper chest, mucus membranes; occur in crops. Get asymptomatic red streaks in nail bed
diagnostics for bacterial endocarditis
- blood cultures
- CBC
- BMP
- Coags
- Echo
treatment for bacterial endocarditis
⦁ PCN G
⦁ Nafcillin
⦁ Gentamycin
⦁ Vanco or Zyvox in MRSA
RMSF caused by
Rickettsia ricketsii spirochete
Rickettsia ricketsii spirochete
RMSF
RMSF
- Caused by Rickettsia ricketsii spirochete
- common in May through September (summer months)
- can be fatal if not treated, especially in the elderly
HISTORY
- hx of tick bite given in 60% of cases
- ask about outdoor activity (camping, etc)
- Prodrome of anorexia, irritability, and malaise***** (before other symptoms that appear 1-2 weeks after tick bite)
RMSF has a prodrome of
anorexia
irritability
malaise
Symptoms of RMSF
symptoms appear 1-2 weeks after tick bite ⦁ fever (> 102) ⦁ chills ⦁ weakness ⦁ Headache*** ⦁ Photophobia***
tick bite, then prodrome of irritability, malaise, anorexia
then have symptoms 1-2 weeks later of headache, photophobia, fever, chills, weakness
RMSF Rash
⦁ only 49% get a rash
⦁ initially 2-6mm pink blanching macules that begin on extremities and spread centrally*
- rash begins on wrists, forearms, ankles, and later on palms
⦁ evolve to papules & petechiae over hours to couple of days
*one of the few conditions where palms & soles develop the rash - just get the rash here later on compared to extremities
⦁ initially 2-6mm pink blanching macules that begin on extremities and spread centrally*
- rash begins on wrists, forearms, ankles, and later on palms
RMSF
*one of the few conditions where palms & soles develop the rash - just get the rash here later on compared to extremities
treatment for RMSF
⦁ Doxycycline
⦁ Chloramphenicol if pregnant
- start antibiotics if diagnosis is even suspected!!
- *Per CDC, give doxy even to children now - less effect on teeth than Tetracycline
Mortality rate = about 60% in elderly
if pregnant, tx for RMSF
chloramphenicol
Borrelia burgdorferi spirochete from a tick bite
LYME DZ
lyme dz rash
- appears several days after infection, or not at all (unlike RMSF where get rash 1-2 weeks later if get rash)
- can last a few hours or up to several weeks
- can have very small or very large lesions
- can mimic hives, eczema, sunburns, poison ivy, flea bites
- can itch, feel hot, or may not be felt at all
- can disappear, but then return several weeks later if not treated
**Typical target lesion
lyme dz symptoms
several days or weeks after bite, patient develops flu-like symptoms
⦁ headache ⦁ stiff neck ⦁ aches and pains in muscles and joints ⦁ low-grade fever and chills ⦁ fatigue ⦁ poor appetite ⦁ sore throat ⦁ swollen glands ⦁ After several months, arthritis-like symptoms may develop, including painful and swollen joints
how is lyme dz diagnosed?
- difficult to diagnose because symptoms are not consistent, and may imitate other conditions. Primary symptom = rash, but this may not be present in upt o 10-15% of cases
- diagnosis for Lyme dz = clinical - must be made by a provider experienced in recognizing LD
- diagnosis usually based on symptoms & hx of tick bite. Testing generally done to elimiate other conditions, and may be supported through blood & lab tests, although, these tests are not absolutely reliable for diagnosing LD
lyme dz treatment
⦁ Doxy for adults & children > 8
⦁ Amoxicillin for adults, children, pregnant or breast feeding
pregnant women tx = chloramphenicol
RMSF
pregnant women tx = amoxicillin instead of doxy
lyme dz
causes of cellulitis
staph
group A strep
- hx of trauma, or may be unaware of wound of entry
- may include dog, cat or human bite
cellulitis can occur in anyone, but common with ________ & __________
diabetes
PVD
cellulitis PE
- warmth, erythema, edema and tenderness of affected area
- the margin of cellulitis will NOT be palpated
- cellulitis with violaceous color & bullae suggests infection with strep pneumoniae
Cellulitis characterized by violaceous color and bullae suggests infection with
strep pneumo
uncomplicated cellulitis
⦁ small area of involvement
⦁ minimal pain
⦁ no systemic signs of illness (fever / chills / dehydration / altered mental status / tachypnea / tachycardia / hypotension)
⦁ no risk factors for serious iillness
no work-up required
work-up for complicated cellulitis (signs of systemic infection)
⦁ CBC
⦁ blood cultures
⦁ CMP
treatment for mild cellulitis
- staph & strep coverage
MILD
⦁ bactrim, clinda, doxy = covers MRSA
⦁ Keflex
⦁ Dicloxacillin
treatment for complicated cellulitis
- hospitalization for IV antibiotics (to cover MRSA+) ⦁ Ancef (Cephalexin) ⦁ Ceftriaxone (Rocephin) ⦁ Ampicillin - Sulbactam ⦁ Zyvox (Linezolid)
cause of Erysipelas
group A beta hemolytic strep
also causes cellulitis - along with staph
fiery-red, indurated, tense, and shiny plaque. Known as “St Anthony’s fire”.
Erysipelas
raised sharply demarcated advancing margins
erysipelas
cellulitis vs erysipelas
erysipelas = lymphatic component & sharp margins
cellulitis = no lymphatics & no sharp margins
ERYSIPELAS
CAUSE
⦁ group A hemolytic strep
- begins as small erythematous patch - progresses to a fiery-red, indurated, tense, and shiny plaque = known as “St. Anthony’s Fire”
- lesion classically exhibits Raised, sharply demarcated, advancing margins which differentiate it from cellulitis, as cellulitis has no lymphatic component, and has indiscreet margins
- inflammation - warmth, edema, and extreme tenderness
- Lymphatic involvement often manifested by overlying skin streaking and regional lymphadenopathy. More severe infxns - may exhibit vesicles & bullae
ERYSIPELAS HAS A PRODROME OF
fever
chills
malaise
(what else has a prodrome? = RMSF)
treatment for erysipelas
⦁ Penicillin G (also used to treat bact. endocarditis) ⦁ Penicillin VK ⦁ Dicloxacillin (Dynapen) ⦁ Keflex (Cephalexin) ⦁ Clindamycin ⦁ Erythromycin ⦁ May need analgesics for pain
treatment for human bite
⦁ Augmentin (Amoxicillin-clavulanate)
⦁ Moxifloxicin (Avelox) - not for pts under 18
⦁ Clindamycin
⦁ don’t forget about a tetanus shot** - give in OPPOSITE extremity
⦁ patient must f/u in 1-2 days
human bite
- common in young males
- think about anaerobes
Routine Lab studies = generally not indicated because the injured population is usually young & healthy. Diagnosis of infection = clinical
Xray = Osteomyelitis, metacarpal head fracture
- closed fist injuries (fist hits teeth)
- chomping type injury
- puncture wound on head from clashes with teeth
DOG & CAT BITES
- consider tetanus & rabies prophylaxis for all wounds
- bacteria for cat bites = Pasteurella
- more penetrating wounds with cat bites because of sharp teeth
- cat bites = higher risk of infection
CLOSURE
- Primary closure for wounds that can be cleaned effectively, but more often left open to heal.
- Facial wounds can be closed
- Lower extremity wounds need delayed closure
- Patient follow-up in 1-2 days
treatment for dog / cat bites
⦁ Augmentin (amoxicillin-clavulanate) ⦁ erythromycin ⦁ Bactrim DS / Septra DS ⦁ Clindamycin ⦁ Cipro
cat bite bacteria
pasteurella
bacterial causes of necrotizing fasciitis
⦁ Group A hemolytic strep
⦁ Staph
⦁ both
(just like with cellulitis)
(erysipelas = just GABHS)
progressive, rapidly spreading, inflammatory infection located in the deep fascia, with secondary necrosis of the subcutaneous tissues
necrotizing fasciitis
most common cause of necrotizing fasciitis
GABHS
most important signs of necrotizing fasciitis
tissue necrosis, putrid discharge, bullae, severe pain, gas production, rapid burrowing through fascial planes, and lack of classical tissue inflammatory signs
diagnosis of necrotizing fasciitis
⦁ CBC with differential ⦁ Chem panel ⦁ Blood and tissue cultures ⦁ Urinalysis ⦁ Arterial blood gas ⦁ Xray ⦁ CT ⦁ Biopsy is best to use when diagnosing
treatment for necrotizing fasciitis
⦁ aggressive antibiotics ⦁ hemodynamic stabilization ⦁ surgical consult for debriding ⦁ ID specialist ⦁ hyperbaric specialist
ANTIBIOTICS ⦁ Ceftriaxone (Rocephin) ⦁ PCN-G ⦁ Clindamycin (Cleocin) ⦁ Flagyl ⦁ Gentamicin (Garamycin) ⦁ Chloramphenicol ⦁ Ampicillin
- chronic, suppurative disease of apocrine gland-bearing skin
hidradenitis suppurativa
apocrine duct or gland
HS
predisposing factors to HS
⦁ obesity
⦁ genetic disposition to acne
⦁ apocrine duct obstruction
common sites for HS
⦁ Axilla
⦁ anogenital region
HS TREATMENT
⦁ ILK - triamcinolone ⦁ PO steroids - prednisone ⦁ surgery - I&D = last resort! - will just come back... ⦁ Oral ABX - Erythromycin - Tetracycline - Minocycline ⦁ Isotretinoin
which HSV herpetic whitlow
HSV I
diagnosis of HSV
- inspection
- Tzanck smear = see giant multinucleated cells
- Direct immuno-fluorescence antibody
- culture (viral)
HSV treatment
⦁ cool compresses
⦁ air or heat lamp - dry of lesions
⦁ Penciclovir (denavir) = topical
⦁ Famciclovir (Famvir) or Valacyclovir (Valtrex)
⦁ Acyclovir = less expensive, but have to take more often
⦁ pain control PRN
when is chickenpox contagious from
⦁ is highly contagious from 2 days before onset of rash until all lesions have crusted
chicken pox rash
- appears on face & scalp, then spreads inferiorly to the trunk (centripetal)
⦁ vesicles - “dew drops on a rose petal”
⦁ pruritic
⦁ become pustules & crust over
treatment for chicken pox
- usually self-limiting
- if symptomatic
⦁ benadryl for pruritus
⦁ tylenol for fever - Systemic
⦁ Acyclovir (Zovirax)
SHINGLES
- more than 60% are > 50 y/o
- involves dermatomes
- reactivation of varicella virus in cutaneous nerves from earlier varicella
- triggering factors
- unilateral, very painful
- flu like prodrome
complications of shingles
Postherpetic neuralgia
Temporary motor paresis
common locations for shingles
⦁ Thoracic
⦁ Trigeminal
⦁ Lumbosacral
⦁ Cervical
shingle lesions
⦁ Papules to vesicles-bullae ⦁ Pustules to crusts ⦁ Erythematous, edematous base with superimposed clear vesicles, sometimes hemorrhagic ⦁ Vesicle is oval or round ⦁ Can have regional lymphadenopathy
warts are caused by
hpv
treatment for shingles
- famvir, valtrex or acyclovir 800mg 5xd for 7-10 days
- oral steroids are controversial
- antibiotic cream to prevent secondary infections
- if extremely painful = - Ultram PO (tramadol)
- burrow’s solution or cool tap water compresses
treatment of genital warts
- all genital warts should be treated ⦁ Podophyllum = treats small areas ⦁ Trichloroacetic acid = particularly helpful for vaginal warts ⦁ Cryosurgery ⦁ CO2 laser ⦁ Electrosurgerry
Treatment does not ensure elimination of wart virus from the area
Round, flat and smooth warts =
plane warts (flat warts)
warts that are Long and thin in shape= Can grow rapidly on the eyelids,neck and armpits.
filiform warts
multiple plantar warts in clusters. Same color as the persons skin
mosaic warts
MOLLUSCUM
Discrete, 2 - 5 mm, umbilicated, dome-shaped papules
Spread by autoinoculation, scratching, or touching a lesion
Common on face, trunk, extremities in children
Common in genital and pubic areas in adults
molluscum treatment
- self-limiting - not necessary to treat in children, but can with ⦁ curettage ⦁ cryosurgery ⦁ TCA / podophyllin ⦁ Retin-A cream ⦁ Cantharidin
