1/22/2019

1

Infectious Disease Amy Smark, MD

Beaumont Health

Royal Oak, MI

Topics

• Pneumonia

• Lung abscess

• Mycobacterial disease

• Bite wounds

• Skin infections

• Parasites

• Tick born disease

• Malaria

• HIV emergencies

Pneumonia

• For purpose of discussion will be subdivided:• bacterial

• aspiration

• atypicals

• fungal

• viral

Pneumonia

• Difficult to discover true etiologic agent

• Empiric treatment chosen by clinical presentation & historic clues

Pneumonia

• Difficult to discover true etiologic agent

• Empiric treatment chosen by clinical presentation & historic clues

• Inpt vs outpt?

• CAP vs HCAP?

• aspiration risk?

• possible ICU admission?

• Pseudomonas risk factors?

• Learn buzzwords for each group & each etiologic agent

Bacterial Pneumonia

• Streptococcus Pneumoniae• Most common pathogen

• Rare in older children and adults < 60 y.o. if no predisposing risk factors

• Classic presentation: abrupt shaking chill & fever, productive cough of rust-colored sputum, pleuritic chest pain

• CXR: classic is lobar consolidation

1 2

3 4

5 6

1/22/2019

2

Lobar consolidation LLL consolidation

Bacterial Pneumonia

• H. Influenza• Second most common

community-acquired adult pathogen.

• G(-) pleomorphic rod

• Often in COPD & debilitated pts

• Patchy infiltrates

Bacterial Pneumonia• Treatment

• Outpatient: • Healthy: macrolides, doxycycline

• Significant comorbidities:

• extended spectrum fluoroquinolone vs

• Augmentin + azitro/doxy

• Inpatient CAP: • ceftriaxone +macrolide or

• extended spectrum fluoroquinolone

• HCAP• 4th gen Cephalosporin/Ext spectrum PCN + cipro/levo/tobra

• PCN allergic-aztreonam

• Consider vanco

Bacterial Pneumonia Klebsiella • G- bacillus

• Associated w/ alcoholism, debilitated state, & nosocomial

• Acute onset high fever & chills, cough w/ currant jelly sputum (necrotizing/ hemorrhagic)

• CXR: classically lobar in one upper lobe

• Often complicated by abscess, empyema & bacteremia

• Tx: 3rd gen cephalosporin +aminoglycoside

• Often ESBL/carbapenem resis, tx guided by susceptibility

7 8

9 10

11 12

1/22/2019

3

Klebsiella: “bulging fissure” Bacterial Pneumonia

• S. Aureus• Hospitalized, debilitated, IVDA

• Increased incidence during influenza season

• Insidious onset following flu

• Patchy, multicentric infiltrates

• Often necrotizing & forms cavitation

• Tx:

• MSSA: oxacillin, nafcillin

• MRSA: vanco, linezolid

Bacterial Pneumonia

• Pseudomonas• Increased risk if recent hospitalization, neutropenia, hx of COPD,

bronchiectasis or CF

• Patchy infiltrates, may also form abscess

• green sputum, fruity odor

• Treatment: 2 drug therapy

• Antipseudomonal beta lactam (cefepime, Zosyn, imipenem) + • cipro/levo/(gent+macrolide)

Aspiration Pneumonia

• Anaerobic organisms & typically polymicrobial

• Suspect w/ lower lobe disease (especially RLL) & clinical risk factors• CNS depression

• Swallowing dysfunction

• Severe periodontal disease

• Fetid sputum

Aspiration Pneumonia

• Bacterial: aspirate oropharyngeal pathogens• Community & nosocomial

• Anaerobes: Bacteroides, peptostreptococcus, fusobacterium

• +/- colonization of enteric Gram (-) and staph

• Subacute or insidious onset

• CXR: infiltrate posterior lower lobes or upper lower lobes

• Tx: antibiotics are the mainstay• Clindamycin if PCN allergic

Aspiration Pneumonia

• Chemical/aspiration pneumonitis: aspirate gastric contents• Initial chemical burn followed by inflammatory rxn;

high mortality & may lead to ARDS

• Abrupt onset of symptoms within 2 hrs

• Wheezing, resp distress, pink/frothy sputum

• CXR: infil in lower lobes or diffuse similar to pulmonary edema

• Tx: • Supportive: supplemental O2, suctioning, mech vent if

needed

• Abx controversial unless secondary bacterial

• If truly chemical aspiration, abx have not shown any long term benefit or change in outcome

13 14

15 16

17 18

1/22/2019

4

Aspiration pneumonia Atypical Pneumonia

• Term introduced in med literature early 1900s to separate from pneumococcal disease• Did not start with sudden shaking chill & fever, have

period of defervescence, & no lobar appearance on X-ray

• Many outbreaks in young adults w/ less severe course

• 1st identified organism: Mycoplasma

• Many others gradually followed: chlamydia pneumoniae, legionella, viruses, rickettsia

• CXR: diffuse interstitial pattern

Atypical pneumonia

• Interstitial infiltrates

Atypical Pneumonia

• Mycoplasma Pneumoniae• “walking pneumonia”• Starts w/ flu-like symptoms in

young adult• Usually nonproductive cough,

pharyngeal erythema, scattered rhonchi

• Bullous myringitis- non specific

• Serum cold aggluttins in 60% (also w/ virus)

• Bilateral interstitial infiltrates• Tx: macrolides or doxy• Key feature: well appearing

with significant interstitial infiltrates

Mycoplasma pneumonia Atypical Pneumonia

• Chlamydia Pneumoniae• Obligate intracellular G- organism

• Clinical picture:

• Young adult- minor URI, subacute & self-limited

• cough may persist for weeks

• No CXR findings is common

• Elderly- more likely to have unilobar infil

• WBC normal

• Dx by nasopharyngeal culture or serology

• Tx with macrolides, doxy, fluoroquinolones

19 20

21 22

23 24

1/22/2019

5

Atypical Pneumonias

• Legionella• Legionella pneumophilia

• Gram (-) bacilli, aerobe, obligate intracellular bacillus

• Some have mild, self-limited course

• Elderly, COPD pts & immunosuppressed have more acute & severe course

• Inhalation of mist from contaminated H2O source

• High fever, cough, chest pain, GI symptoms (N/V/D), AMS

• Hypotension, relative bradycardia

• Hyponatremia, elevated LFTs & Bili

• Urinary antigen test: most rapid dx (1-3d); +in 80%

• Tx: macrolides, resp fluoroquinolones 1st line

Atypical Pneumonias

• Zoonotic Causes: consider as cause based on contact history

Atypical Pneumonias

• Psittacosis• Chlamydia psittaci

• Birds

• Inhalation of dust or droplets

• Owners of birds/pet shop employees/poultry workers/vets

• High fever, HA, HSM

• Labs: ↓WBC, ↑LFTs, proteinuria

• Perihilar infiltrates

• Tx: tetracycline/doxy

• Erythromycin in age <9

• Tx x3weeks.

Atypical Pneumonias

Atypical Pneumonias

• Tularemia• Francisella tularenesis

• Aerobic G- pleomorphic rod• Rabbits, ticks

• Direct contact vs inhalation

• Ulceroglandular: lesion at site of contact with regional LAD

• Typhoidal: fever, chills, HSM

• Pneumonia

• Tx: streptomycin (1st line), gentamicin, doxy, cipro

Atypical Pneumonias

• Coxiella brunetti• Causes Q fever

• intracellular

• Domestic animals, Sheep

• Highly infectious, can live long periods of time (up to 18 months) in soil and in water or milk for 42 months

• Inhalation of contaminated dust

• Slaughterhouse workers, dairy farmers

• ↑LFTs, high fever

• Dx with serologic studies

• Tx: doxycycline

25 26

27 28

29 30

1/22/2019

6

Viral Pneumonias

• CXR nonspecific

• Treatment is generally supportive

• Influenza• Most common cause of viral pneumonia in adults

• Risk for elderly and pregnant patients

• Tamiflu in first 48 hrs

• RSV• RSV Ag unreliable in adults and not recommended

Viral Pneumonias

• Parainfluenza• Pneumonia, croup, bronchitis

• Varicella• 2-5 days after fever & rash

• Severe in pregnancy

• Admit for IV acyclovir

• CMV, EBV• Post-transplant patients, AIDS patients

• IV gancyclovir

Fungal Pneumonias

• Endemic: can infect healthy persons• Usually self-limited

• Opportunistic: infect immunocompromised• High mortality rate

• Diagnosis via bronchoscopy

• Inhalation of spores, condida, or latent infection reactivation

• Clue: person w/ activity near soil

Endemic Fungal Pneumonias

• Histoplasma capsulatum• Mississippi & Ohio river valley

• Bird, bat droppings

• Can vary from asymptomatic to disseminated with multisystem organ failure in immunosuppressed

• Coccidioidies immitis• Southwestern

• Most self-limited

• Blastomyces dermatitidis• Similar area to histoplasma but more extensive

• Can be severe in immunosuppressed

• Soil disruption

Opportunistic Fungal Infections

• Candida• HIV/AIDS, cancer pts

• Thrush/esophageal candidiasis

• Tx: azoles

• Aspergillus• Soil

• Pneumonia, cutaneous, ocular

• Voriconazole 1st line, amphotericin

Opportunistic Fungal Infections

• Mucor• Diabetics• immunocompromised• Emergent sx• Tx: amphotericin b

• Cryptococcus neoformans• Encapsulated yeast• Pigeon excrement• Immunocompromised/HIV• Lung and CNS infection most

common• Tx: fluconazole (non-CNS),

amphotericin +flucytosine

31 32

33 34

35 36

1/22/2019

7

Complications of Pneumonia

• Lung Abscess• Cavity caused by necrosis of tissue filled w/ debris & fluid

• Most commonly caused by aspiration & anaerobic infection

• Indolent symptoms, foul smelling sputum

• Bacterial causes- S. aureus, Klebsiella• More acute & treated @ same time as pneumonia

• Other causes- infected bullae, carcinoma obstructing a bronchus

Lung Abscess

• Hallmark• air/fluid level

Lung Abscess Complications of Pneumonia

• Lung Abscess• Treatment:

• Continue to treat empirically till organism isolated

• Clindamycin if aspiration suspected

• Duration of antibiotics: 4-6 weeks

• Rarely surgical: percutaneous drainage or resection

Complications of Pneumonia

• Empyema• Pus in the pleural space

• CXR: fluid in the fissure

• Treatment:• Usually antibiotics & pleural drainage

• If loculated- may require surgical intervention

Empyema

37 38

39 40

41 42

1/22/2019

8

Tuberculosis

• Mycobacterium tuberculosis• obligate aerobic rod w/ acid-fast staining properties

• 1/3 world population is infected

• Primary TB• 90% asymptomatic• Lower lobes• + skin test +/- Ghon complex on CXR

• Reactivation TB• Most common clinical form• Fever, night sweats, malaise, productive cough• Upper lobes, areas of high oxygen tension

Tuberculosis

• Ghon complex

Tuberculosis

• Extrapulmonary TB• Meningitis

• CSF: decreased glu; increased prot & WBCs (similar to aseptic meningitis)

• Genitourinary• Dysuria, hematuria, pyuria w/o bacteria

• Miliary (disseminated)• Bloodstream seeding• Symptoms depend upon site

• Osteomyelitis (Potts)• LAD• And many more!

Tuberculosis

• TB & HIV• AIDS-defining illness• More often atypical symptoms/ CXR findings & often

multidrug resistant

• Diagnosis:• Skin test

• >5mm if HIV, abnl CXR, exposure• >10mm if IVDA, healthcare workers, immigrants• >15mm all others

• CXR• AFB Studies

• Sputum via Ziehl-Neelsen or fluorescent stain• Culture of sputum for AFB

Tuberculosis

• Primary TB• Small infiltrates in any

area & unilateral hilar adenopathy

• Ghon complex: calcified complex

Tuberculosis

• Reactivation• Upper lobe apices or

posterior

• +/- cavitation

43 44

45 46

47 48

1/22/2019

9

Tuberculosis

• Miliary• Scattered, multiple

small nodules bilaterally

Tuberculosis

• Treatment:• 4 drugs currently 1st-line

• 1) Isoniazid (INH)• Give w/ Vit B6 to prevent peripheral neuropathies

• CYP 450 inducer• 2) Rifampin

• Orange-colored body secretions• 3) Pyrazinamide

• Increased uric acid, hepatitis• 4) Ethambutol

• Optic neuritis (ethambutol)

• 4 drug Tx for 8 weeks• Followed by INH/RIF for 18 wks• Close ID care

Bite Wounds

• 3 to know: human, dog, cat

• Human:• Polymicrobial; both anaerobes & aerobes

• Staph, Strep, Eikenella

• Tdap needed & discuss hepatitis/HIV risk

• Hand has high rate of infection whereas other locations similar rate as other lacerations

• Closed fist and full thickness of the hand considered high risk

Bite Wounds

• Human:

• Management: hand• Xray, full neurovascular assessment,

• Irrigate & debride

• Leave open for delayed closure and splint in position of function

• <24 hrs & no concomitant tendon, joint or bone injury– D/C on Augmentin w/ F/U 1-2d

• >24hrs, already w/ signs of infection, or debilitated state—IV abx

• Unasyn/Zosyn

• Ceftriaxone + flagyl

• Clinda + Bactrim vs cipro

Bite Wounds

• Human

• Management: Body• If low risk --Generally treat similar to other lacerations

• If high risk (deep puncture, crush wound, presenting >24 hrs, or debilitated) place on Augmentin and delayed closure

• Localized infection can generally be treated w/ oral antibiotics

Bite Wounds

• Dog• Polymicrobial: staph, strep, +/- Pasteurella

• Overall infection risk: 5-10%; greatest on hand & least on face

• Capnocytophaga canimorsus

• Rare infection 2-3d following bite

• Causes overwhelming sepsis, DIC, & gangrene @ bite site

• Always consider rabies

• Pet? Stray? Shots?

49 50

51 52

53 54

1/22/2019

10

Bite Wounds

• Dog• Management:

• Prophylactic antibiotics for hand, high-risk wound, immunocompromised• Augmentin (1st line)

• PCN or Bactrim or fluoroquinolone + clinda or flagyl

• If infection occurs <24 hrs– Pasteurella

• If infection occurs >24 hrs– staph/strep/cc• Augmentin, dicloxacillin

• Suturing-

• Hand: delayed

• <12 hrs: close, esp facial

• >12 hrs: delayed

Bite Wounds

• Cat• Typical bite is puncture

• Higher risk of infection than dog bite

• Staph, strep as in other bites

• Pasteurella incidence much higher than dogs

• Earlier onset of infection: usually within 6-24 hrs

• Can occur with scratch

Bite Wounds

• Cat• Management:

• Prophylactic antibiotics for all wounds

• Augmentin 1st line

• Infected bites usually require IV abx

• Same choices of antibiotics

• Tetanus/rabies

• Suture: face only

• General rule—puncture wounds should not be sutured

Bite Wounds

Bite Wounds

Subcutaneous

emphysema

Skin Infections

• 5 types to be discussed:• 1) Abscess

• 2) Necrotizing fasciitis

• 3) Cellulitis

• 4) Erysipelas

• 5) Impetigo

55 56

57 58

59 60

1/22/2019

11

Abscess

• Localized collection of purulent material forming a fluctuant mass surrounded by erythema

• Extremity: usually follows break in skin integrity

• Head/Neck & perineal: apocrine or sebaceous duct obstruction

• Perirectal: anal crypt bacteria spread

• Vulvovaginal: Bartholin’s duct obstruction

• Pilonidal: embedded hair

Abscess

• Anaerobic: • more common in mucous membrane involvement

• Aerobic: • more common in cutaneous

• Staph Aureus #1

• Ultrasound useful to delineate & R/O radiopaque foreign bodies

Abscess• Simple Cutaneous Management:

• incision & drainage

• Antibiotics in immunocompromised or significant surrounding cellulitis

• MRSA- chronic, recurrent infection

• Hidradenitis Suppuritiva• Chronic, reoccurring abscesses of apocrine glands

• Sinus tracts & fistulas often form

• Frequently require surgical drainage

Abscess

• Bartholin Cyst:

• Post-lat vaginal opening

• Mixed flora

• 10% Gonorrhea/ Chlamydia

• I & D followed by placement of Word catheter

• Catheter for 4-6 wks so that a sinus tract may form

Abscess

• Perirectal

FACRS.org/American society of Colon and rectal surgeons

Abscess

• Perirectal

• Originate in anal crypts & extend to ischiorectal space

• May have underlying fistulas

• Perianal

- I& D in radial direction from anal opening

- Abx only if systemic signs

• Intersphincteric

• Ischiorectal

61 62

63 64

65 66

1/22/2019

12

Abscess

• Pilonidal• Location: gluteal fold over coccyx

• Process: small pit forms from epithelial disruption, plugs with hair & epithelium, becomes tender fluctuant nodule

• Treatment: I & D with removal of plug; refer for more definitive care if sinus tract present or if deep

Pilonidal cyst/abscess

Necrotizing Fasciitis

• Usually mixed flora infection of anaerobes & aerobes• Clostridium, Grp A Strep

• Early signs similar to infected wound but rapid progression, deep pain out of proportion to outward signs• Necrotic patches & bullae ensue

• X-ray: gas in tissues

• Fever

Necrotizing fasciitis

• Bullae • Fournier’s

Necrotizing Fasciitis

• Fournier’s• Perineum usually males, affecting penis & scrotum

• Pain 1st then swelling, fever, crepitance, erythema, inflammation

• Treatment:• Always early surgical consult for aggressive

debridement

• IV abx against Staph/Strep, gram neg & anaerobes• Vanco +

• Zosyn + clinda

• Carbapenem + clinda

• Consider adding fluoroquinolone if freshwater exp

Cellulitis

• Local inflammation of skin presenting w/ warmth, localized pain, induration & erythema

• Preceding trauma, hematogenous or lymphatic spread

• Clinical diagnosis

• R/O bacteremia if diabetic/immunosuppressed

• Staph/strep & also H. Inf in kids

• Treatment:

• Outpatient: previously healthy & non-toxic

• Keflex (low risk MRSA)

• Clinda

• Bactrim +keflex

• Doxycycline

• Inpatient: • IV abx if diabetic, immunosuppressed, febrile, asplenic

or if involving head/neck or >50% extremity

67 68

69 70

71 72

1/22/2019

13

Cellulitis

• Periorbital (pre-septal)• trauma (insect bite/infect)

• Reach periorbital area by either hematogenous spread or direct extension from ethmoid sinus

• Highest incidence < 3

• More likely to be bacteremic

• Fever more common

• Periorbital edema more prominent

• Orbital• Can occur at any age

• Contiguous spread most common

• Proptosis or limitation/painful extraocular muscle function

Cellulitis

• CT• CT is performed when orbital involvement is likely

• CT with contrast needed for periosteal abscess

Cellulitis

• periorbital • orbital

Cellulitis

Periorbital

• Infection confined to tissue ant to orbital septum

• Periorbital edema

• Erythema

• Staph, strep, h.flu

• EOM, visual acuity, pupils normal

• Tx: blood cultures, oral abx if good outpt f/u.

• IV Abx (unasyn, rocephin)

Orbital

• Tissues within the orbit post to the septum

• Edema, proptosis, pain on EOM, limitation of EOM, pupillary abn

• Admit, IV Abx, ophtho

Orbital cellulitis

73 74

75 76

77 78

1/22/2019

14

Erysipelas

• Cellulitis involving dermis, lymphatics & subcutaneous tissue

• Most commonly on lower extremities; also face

• **raised plaque, deeply demarcated border, painful & erythematous

• Grp A strep main cause

• Very young or age > 50

• Often appear toxic & are febrile

• Treatment:

• Toxic appearing, IV abx

• Penicillinase-resistant PCN or 2nd/3rd gen cephalosporin

• If non-toxic: amox, keflex, clinda po

Impetigo

• Skin infection confined to epidermis

• Staph/strep

• Usually less than 6 yrs old

• Highly contagious/autoinoculation

• 2 varieties:• impetigo contagiosa– papule then vesicles then honey-colored crusted

lesions

• bullous impetigo– superficial bullae w/ purulent material

Impetigo

• Treatment:

• To decrease risk of cellulitis

• Keflex or Mupirocin

• Won’t decrease incidence of post-strep glomerulonephritis

• Rheumatic fever is NOT a complication

Parasitic Infections

• 6 types to be discussed:• 1) Pediculosis

• 2) Scabies

• 3) GI- Ascaris

• 4) GI- Pinworms

• 5) GI- Schistosomiasis

• 6) Malaria

Pediculosis

• Pediculus humanuscapitis (head lice)• Itching

• Often occiput, postauricular scalp

Pediculosis

• Pediculus humanus corporis (body)

• Pithirus pubis (pubic)

• Treatment:• Permethrin (nix)

• 1st line

• Apply to scalp when hair is dry for 10 min then rinse• Repeat dose in 1 week

• Ivermectin po• Treatment failures• Age >10, not pregnant/bf

• Lindane (kwell)• Reserved for treatment failures• CNS toxicity & seizures (esp children)

79 80

81 82

83 84

1/22/2019

15

Scabies

• Mite infestation

• Presentation: papules surrounded by erythema & scratch marks

• Kids—more generalized

• Areas: interdigital web spaces, wrists, axilla, genitals

• Highly contagious

• Tx for infected and close personal/household members• Permethrin, tx x2

• Po Ivermectin (caution pregnancy, children)

• Clothing, bedding

Scabies

Ascaris

• Large nematode & is most common roundworm

• Most common parasite worldwide

• Eggs are ingested, larvae hatch, migrate through body & re-enter GI tract

• Children & those w/ heavy worm burden: worms may tangle & cause SBO

• Also causes appendicitis

• Dx: via increased eosinophils & eggs in stool

• Tx: • Albendazole, mebendazole• Pyrantel pamoate in

pregnancy

Pinworms

• Enterobius vermicularis

• Most common roundworm in the U.S.

• Ingested thru transfer of eggs from anus to mouth via fingers

• Clinical: causes intense perianal itching worse at night

Pinworms

• Diagnosis: tape test

• Treatment: Albendazole/Mebendazole• All family members get treated

• Wash all towels, blankets, sheets in hot water

Schistosomiasis

• Not endemic to US

• Parasites infect snails that release larvae & enter into humans thru intact skin, then migrate thru vasculature, become worms & release eggs

• Eggs cause intense immunologic response

• Symptoms depend on where the eggs migrate• Bowel—bloody diarrhea

• Bladder—hematuria, bladder ulcers

• Portal circulation—hepatic disease & portal HTN

• CNS—seizures, transverse myelitis, AMS

85 86

87 88

89 90

1/22/2019

16

Schistosomiasis

• Acute Illness• Present several wks after contact w infested water

• Serum sickness type illness: fever, HA, RUQ pain, bloody diarrhea, malaise

• Chronic Illness• Presents months to years after initial infection

• Again depends on location of migration & worm burden

• Treatment• po Steroids if significant inflammation

• Praziquantel, may need repeat dose

Malaria

• Predominantly in tropics

• 4 species:

• P. falciparum (most deadly), P. Ovale, P. Vivax, P. malariae

• Via infected mosquito

• Life cycle thru hepatocytes then replicate in erythrocytes

• Symptoms start a few weeks after infection but may be up to several months

Malaria

• Symptoms• Irregular fevers is hallmark

• Only chronic infection have periodicity to fevers

• Nonspecific signs: lethargy, HA, abd pain

• Severe infection: anemia, HSM, coma, resp failure

• Diagnosis• Blood smear

Malaria

• Treatment• Must speciate to treat• Review CDC updates• Doxycycline plus quinine• Review Chloroquine

resistance• Artemisinin combination

therapy (ACTs)

Tick-Borne Infections

• 2 to be discussed:• 1) Lyme

• 2) RMSF

Lyme

• Caused by spirochete: Borrelia burgdorferi

• Ixodes tick is the vector

• New England and Mid Atlantic states

• May to August is highest incidence

• Incubates several days to weeks then migrates to any site in the body

91 92

93 94

95 96

1/22/2019

17

Erythema Migrans

• Circular lesion with bright red border, pale interior; warmth; non-tender

Lyme

• Stages of Illness

• Stage I: within 1 month; localized

• Fever, malaise

• Erythema migrans- **hallmark

• Stage II: weeks to months later; disseminated

• Neurologic signs predominate: fluctuating meningoencephalitis, cranial neuropathies (Bell’s most common), peripheral neuropathies

• Cardiac: myocarditis & AV Block

Lyme

• Stage III: months to yrs later; chronic• Migratory oligoarthritis

• Vast neurologic complaints

• Diagnosis: serologic IgM & IgG• EM in an endemic area is diagnostic

• CSF may mimic viral meningitis

• Treatment: depends on stage & symptoms• Stage I adult, non-preg & >8yo: doxycycline X 10-21d

• Stage I pregnant or < 8yo: amoxicillin X 21d

• Stage II Bell’s: treat as Stage I

• Stage II serious CNS disease & carditis: ceftriaxone

• Stage III: ceftriaxone or PCN X 30d

RMSF

• Rickettsia ricketsii carried by female Dermacentor tick

• Name is misnomer as cases from Canada to Brazil

• Peak in spring & summer

• Symptoms caused by rickettsia infecting vascular endothelial & smooth mm cells leading to a vasculitis

RMSF

• Clinical features:

• Fever, severe HA, myalgias, GI complaints usually around 7d after tick

• Rash: 2-6 days after fever; starts as erythematous blanching macules on flexor surface of wrists, ankles

RMSF

• Rash:• Spreads to palms/ soles then

moves centrally to cover body in 6-12 hrs

• Becomes deeper red & maculopapular in 2-3d then fixed & petechial

97 98

99 100

101 102

1/22/2019

18

RMSF

• Other Clinical Features:• **gastrocnemius TTP

• Myocarditis, interstitial pneumonitis, vast neurologic manifestations

• Diagnosis:• Presumptive diagnosis

• Serology testing or skin biopsy to confirm, do not wait for results to treat

• Treatment:• Doxycycline, best outcomes starting in 5 days of onset

• Only mildest cases treated as outpt

HIV I.D. Emergencies

• 3 diseases to discuss:• 1) PCP

• 2) Cryptococcus neoformans

• 3) Toxoplasma gondii

PCP

• Pneumocystis jirovecii

• PneumoCystis Pneumonia (PCP)

• most common opportunistic infection in AIDS

• A fungus but responds to antiparasitic agents

• Occurs in adults with CD4 count < 200

• Symptoms often develop slowly over 1-2 weeks

PCP

• Clinical Features

• Hypoxia • Can be significant

• Tachypnea, tachycardia, mild fever

• Increased LDH is marker of severity

• CXR• May be normal early

• Classically: bilateral diffuse interstitial infiltrates from perihilar area (batwing)

• Pt may not know HIV status-high index of suspicion

Pneumocystis pneumonia PCP

• Diagnosis:• Examination of sputum using immunofluorescent

staining• BAL

• Treatment:• Initiate when suspected• Bactrim po or IV X 14-21d• IV Pentamidine• TMP +dapsone

• Steroids for mod-sev infection (low O2)• initiate before abx• RA PaO2<70 mmHg

103 104

105 106

107 108

1/22/2019

19

Cryptococcus Neoformans

• Most common meningitis in HIV pts

• May cause focal cerebral lesions or diffuse meningoencephalitis

• Symptoms:• fever, HA, vertigo, photophobia, seizures, CN palsies

• Diagnosis:• Head CT to R/O lesion then LP

• India ink prep & fungal cx• Serum antigen titer is most sensitive

• Treatment:• Mild Pulmonary dz: fluconazole, itraconazole

• Severe Infections/meningitis: Amphotericin + flucytosine

Cryptococcus

Toxoplasma Gondii

• Most common focal encephalitis & mass lesionin AIDS patients

• Symptoms: fever, HA, AMS, focal neurologic signs

• Diagnosis:• Head CT showing ring-enhancing lesions (“signet ring

sign”) w/ contrast

• IgG, IgM, IgA Ab’s

• May be unreliable in immunosuppressed pts

• Treatment:

• Pyrimethamine + Sulfadiazine + leucovorin

Toxoplasmosis

109 110

111 112

113