Bacterial & Viral Infections Flashcards
Characteristics of Impetigo
Common, contagious, superficial skin infection Culprits: strep, staph, or both Self limiting High incidence in children Post strep glomerulonephritis
PE Findings in Impetigo
Nonbullous and/or bulls
Vesicles & bullae contain clear yellow or slightly turbid fluid without surrounding erythema
“Honey” crusted
Treatment of Impetigo
Bactroban (Mupirocin) ointment
Severe: oral antibiotics (Bactrim, clindamycin, or doxycycline)
Characteristics of Meningococcemia
N. meningitidis
Highest incidence: midwinter-early spring ages 6 months-3 years
Most rapidly lethal form of septic shock
PE Findings in Meningococcemia
High fever Tachycardia Mild hypotension Meningeal irritation Appears acutely ill
Early Exanthem of Meningococcemia
Soon after onset
Pink macules/papules, sparsely distributed on trunk/lower extremities, face, palate, conjunctivae
Later Lesions of Meningococcemia
Petechiae in center of macules
Lesions become hemorrhagic within hours
Purpura fulminans
Hemorrhagic bullae
Work Up of Meningococcemia
Blood cultures
Pus from nodular lesion
D-dimers
Treatment of Meningococcemia
Cefotaxine (Claforin)
Ceftriaxone (Rocephin)
Hemodynamic stabilization
Characteristics of Bacterial Endocarditis
Staph aureus or strep viridans
Proliferation of microorganisms on the endocardium of the heart
Incidence increasing in elderly, IVDU, & prosthetic valves
Important H&P Findings for Bacterial Endocarditis
Fever Chills/sweats Anorexia/weight loss/malaise Heart murmur Arterial emboli Splenomegaly Hematuria
Skin Lesions in Bacterial Endocarditis
January lesions
Osler’s nodes
Subungual Splinter hemorrhage
Petchial lesions
Describe Janeyway Lesions
Non-tender, hemorrhagic maculopapular lesions on palms & soles
Describe Osler’s Nodes
Painful, red nodules on fingertips
Describe Petechial Lesions
Small, non-blanching, reddish-brown merciless on extremities, upper chest, mucus membranes
Occurs in crops
Asymptomatic red streaks in nail bed
Work Up for Bacterial Endocarditis
Blood cultures CBC CMP Coags Echo
Treatment of Bacterial Endocarditis
PCN-G Nafcillin Gentamycin Vanco in MRSA Zyvox in MRSA
Characteristics of Rocky Mountain Spotted Fever
Common May-September
Can be fatal
Important History to Obtain for Rocky Mountain Spotted Fever
Hx of tick bite
Outdoor activity
Prodrome: anorexia, irritability, malaise
PE Findings of Rocky Mountain Spotted Fever
1-2 weeks after bite Fever (>102) Chills Weakness Headache Photophobia
Skin Lesions in Rocky Mountain Spotted Fever
Initially: 2-6 mm, pink blanching macules on extremities; spread centrally
Evolve to papules & petechiae over hours to days
Rash Movement in Rocky Mountain Spotted Fever
Wrists
Forearms
Ankles
Palms
Treatment for Rocky Mountain Spotted Fever
Doxycycline
Pregnancy: Chloramphenical
Bug that Causes Lyme Disease
Spirochete Borrelia burgdorferi
Rash Description of Lyme Disease
Appears several days after infection Last few hours to several weeks Very small or very large Mimic hives, eczema, sunburn, poison ivy, flea bites Can itch/feel hot or not felt at al Can disappear and return later
Symptoms of Lyme Disease
Headache Stiff neck Aches & pains in muscles & joints Low-grade fever & chills Fatigue Poor appetite Sore throat Swollen glands Arthritis-like symptoms may develop
Diagnosing Lyme Disease
Look for rash
Based on symptoms & Hx of tick bite
Treatment of Early-Stage Lyme Disease
Doxycycline: >8 years
Amoxicillin: adults, children, pregnant or breast feeding women
Characteristics of Cellulitis
Acute, spreading infections of dermal & subcutaneous tissues through a skin portal Staph aureus & group A strep Hx of trauma Dog, cat, human bites Common in DM & PVD
PE Findings in Cellulitis
Warmth Erythema Edema Tenderness of affected area Margin not palpable Violaceous color & bullae = strep pneumo
Systemic Signs of Cellulitis
Fever Chills Dehydration Altered mental status Tachypnea Tachycardia Hypotension
Work Up for Complicated Cellulitis
CBC
Blood cultures
Chem panel
Treatment of Mild Cellulitis
MRSA: bactrim, clindamycin, doxycyclinee
Cephalexin (Keflex)
Dicloxacillin (Dynapen)
Treatment of Complicated Cellulitis
Hospitalization for IV antibiotics Ancef (Cephalexin) Ceftriaxone (Rocephin) Ampicillin-Sulbactam Zyvox
Characteristics of Erysipelas
Raised, sharply demarcated advancing margins
Inflammation: warmth, edema, & extreme tenderness
Regional lymphadenopathy
Fiery-red, indurated, tense, & shiny plaque
Prodrome of Erysipelas
Malaise
Chills
Fever
Treatment of Erysipelas
Penicillin G Penicillin VK Dicloxacillin (Dynapen) Keflex (Cephalexin) Clindamycin Erythromycin Analgesics for pain
Types of Human Bite Injuries
Closed fist
Chomping type
Puncture wounds head from clashes with teeth
Treatment of Human Bites
Amoxicillin-Clavulate (Augmentin) Moxifloxin (Avelox) Clindamycin Tetanus shot Follow up in 1-2 days
What should be given as prophylaxis for all dog & cat bite wounds?
Tetanus
Rabies
Treatment of Dog & Cat Bites
I&D
Follow up in 1-2 days
Antibiotics: amoxicillin-clavulate (Augmentin), erythromycin, bactrim DS, septum DS, clindamycin, cipro
Characteristics of Necrotizing Fasciitis
Hemolytic strep gangrene
Progressive, rapidly spreading, inflammatory infection in the deep fascia
Anaerobic bacteria + aerobic gram - organisms
Group A beta hemolytic strep, staph
Important History to Diagnosing Necrotizing Fasciitis
Trauma/recent surgery
Insect bites, surgical procedures, IM injections, IV infusion
Sudden onset in pain & swelling
Local pain progresses to anesthesia
PE Finding in Necrotizing Fasciitis
Area of erythema that spreads
Margins move out into normal skin
Dusky or purplish skin discoloration
Produce large area of gangrenous skin
Important Signs of Necrotizing Fasciitis
Tissue necrosis Putrid discharge Bullae Severe pain Gas production Rapid burrowing through fascial planes Lack of classical tissue inflammatory signs
Work Up of Necrotizing Fasciitis
CBC with differential CMP Blood & tissue cultures Urinalysis Arterial blood gas Xray CT Biopsy
Treatment of Necrotizing Fasciitis
Aggressive antibiotics Hemodynamic stabilization Surgical consult for debriding Infectious disease specialist Hyperbaric specialist
Antibiotics to Treat Necrotizing Fasciitis
Ceftriaxone (Rocephin) PCN-G Clindamycin (Clecin) Flagyl: good for anaerobes Gentamicin (Garamycin) Chloramphenicol (Chloromycetin) Ampicillin (Omnipen)
Characteristics of Hidradenitis Suppurativa
Chronic, suppurative disease of apocrine gland-bearing skin
Onset from puberty to climacteric
Predisposing factors: obesity, genetic disposition to acne, apocrine duct obstruction
Common Sites for Hidradenitis Suppurativa
Axilla
Anogenital region
Important History for Hidradenitis Suppurativa
Intermittent pain
Marked point tenderness related to abscess formation
PE Findings of Hidradenitis Suppurativa
Very tender, red inflammatory nodules Drain purulent/seropurulent material Open comedones/double comedones Fibrosis, bridge scars Lesions may become infected
Treatment of Hidradenitis Suppurativa
Intralesional glucocorticoids: triamsinolone
PO steroids: prednisone
Surgery: I&D
Oral Antibiotics: erythromycin, tetracycline, minocycline
Isotretinoin
Primary Herpes Infection
Symptomatic or asymptomatic
Spread by direct contact or fluid
Symptoms of a Primary Herpes Infection
3-7 days after contact Tenderness Pain Mild paresthesias or burning Grouped vesicles on an erythematous base Centers become depressed Crusts form & heal without scarring Virus enters nerve endings and moves to dorsal root ganglia
Type I Herpes Virus
Oral & labial herpes simplex
Whitlow-fingers
Type II Herpes Virus
Genital herpes
Primary/recurrent
May mimic zoster in sacral distributions
Diagnosis of Herpes Simplex
Inspection
Tzanck smear
Direct Immuno Fluorescence Antibody
Viral culture
Treatment of Herpes Simplex
Cool compresses
Air or heat lamp drying of lesions
Medications
Pain control PRN
Medications to Treat Herpes Simplex
Penciclovir (Denavir): topical
Famciclovir (Famvir)
Valacyclovir (Valtrex)
Acyclovir
How long is varicella (chicken pox) contagious for?
Two days before onset of rash
Until all lesions have crusted
Appearance of Varicella
“Dew drops on a rose pedal”
Pruritic
Becomes pustules & crusts over
Treatment of Varicella (Chicken Pox)
Self limiting
Symptomatic: Benadryl, Tylenol
Systemic: acyclovir (Zovirax)
Describe Herpes Zoster (Shingles)
Reactivation of varicella virus in cutaneous nerves from earlier varicella
Unilateral
Very painful
Flu-like prodrome
Common Areas for Herpes Zoster (Shingles)
Thoracic
Trigeminal
Lumbosacral
Cervical
Skin Lesions with Herpes Zoster (Shingles)
Papules to vesicles-bullae Pustules to crusts Erythematous, edematous base Superimposed clear vesicles Vesicle oval or round Regional lymphadenopathy
Complications with Herpes Zoster (Shingles)
Postherpetic neuralgia
Temporary motor paresis
Treatment for Herpes Zoster (Shingles)
Famvir, Valtrex, or Acyclovir \+/- oral steroids Antibiotic cream Burrow's solution or cool compress Ultram PO
Describe Genital Warts
Papilloma virus
Spread rapidly over moist areas
Small papules to large veracious lesions
May extend to vaginal tract, urethra, rectum
Treatment of Genital Warts
Podophyllum: small areas Trichloroacetic acid (vaginal) Crysurgery Carbon dioxide laser Electrosurgery
Molluscum Contagiosum
Discrete, umbilicated, domed-shaped papules
Auto-inoculation, scratching
Children: on face, trunk, extremities
Adults: genital & pubic areas
Treatment of Molluscum Contagious
Curettage Cryosurgery TCA/Podophyllin Retin A cream Cantharidin
