Tag: ID

Viral Hepatitis

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Viral Hepatitis
👾
·       Hep A: Feco-oral
·       Hep B + C: Blood / sex
Path
Viral infection of liver parynchma
Clx
·       Jaundice + Fever
·       Dark urine
·       HSM
·       weight loss, and fatigue
Dx
·       LFT: ⤴️ direct bilirubin / ALP / AST&ALT
·       Serology (for all except hep B):
·       IgM antibody for the acute infection
·       IgG antibody to detect resolution of infection.
·       Disease activity of hepatitis C is assessed with PCR for RNA level
·       Hep B: u know it
Tx
·       Hepatitis A and E resolve spontaneously
·       Tx only Hep C:
·       Genotype 1: ledipasvir and sofosbuvir
·       Other genotype: sofosbuvir and velpatasvir
·       Tx of Chronic Hep B:
·       positive for e-antigen with an elevated level of DNA polymerase, treatment is any one of the following: entecavir, adefovir, lamivudine, telbivudine, interferon, or tenofovir.
Extra
·       If pt has fibrosis on Bx (Hep b / c): start tx
·       In Hep C: If the PCR-RNA viral load is elevated, patients should be treated.

Hepatitis C
Dx
·       IgG + IgM
·       PCR RNA
·       Everyone born between 1945 and 1965 is tested for hepatitis C regardless of risk factors.
·       Viral load testing has nearly eliminated the need for liver biopsy.
Tx
·       If the PCR-RNA viral load is elevated, patients should be treated.
·       If there is fibrosis on liver biopsy, initiating treatment becomes more urgent
·       Genotype 1 is treated with sofosbuvir + ledipasvir orally for 12 weeks.
·       The other genotypes are treated with sofosbuvir and velpatasvir orally.
·       Interferon is only used in treatment failure. 

Zoonotic Infections

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Stage
Lyme disease clinical features
Early localized
(days-1 month)
·       Erythema migrans
·       Fatigue, headache
·       Myalgias, arthralgias
Early disseminated
(weeks-months)
·       Multiple erythema migrans
·       Unilateral/bilateral CN palsy (CN VII)
·       Meningitis
·       Carditis (AV block)
·       Migratory arthralgias
Late
(months-years)
·       Arthritis
·       Encephalitis
·       Peripheral neuropathy
Human monocytic ehrlichiosis
#
·       Transmitted by tick vector (Ione star tick)
·       Seen in southeastern & south central United States
Clx
·       Flu-like illness (high fever, headache, myalgias, chills)
·       Neurologic symptoms (confusion)
·       Rash is uncommon (<30% in adults) ("Rocky Mountain spotted fever without the spots")
Labs
·       Leukopenia & thrombocytopenia
·       Elevated liver enzymes & lactate dehydrogenase
Dx
·       Intracytoplasmic morulae in monocytes
·       Polymerase chain reaction testing for E chaffeensis/E ewingii
Tx
·       Empiric doxycycline while awaiting confirmatory testing
Echinococcus granulosus
#
• Dog tapeworm (sheep intermediate host)
• Rural, developing countries (eg, South America, Middle East)
• Humans are incidental hosts (egg ingestion)
Clx
• Initially asymptomatic (Often for years)
• Liver cyst (most common)
O Mass effect — RUQ pain, nausea, vomiting, hepatomegaly
o Rupture — fever, eosinophilia
• Lung cyst — cough, chest pain, hemoptysis
Dx
• Imaging — large, smooth hydatid cyst often
with internal septations
• lgG E granulosus serology
Tx
• Albendazole
• Percutaneous therapy (>5 cm or septations)
• Surgery (if rupture)
Bacillary angiomatosis
#
·       Bartonella henselae/quintana
·       Cat exposure or homelessness (lice)
·       Severe immunocompromise (Advanced HIV (CD4 <100/mm3)
S/S
·       Vascular cutaneous lesions (papular, nodular, peduncular)
·       Systemic symptoms (fever, night sweats, fatigue)
·       Organ involvement rarely (liver, bone, CNS)
Dx
·       Lesional biopsy with microscopy/histopathology
Tx
·       Doxycycline or erythromycin 💊
·       Antiretroviral therapy
Human rabies
Pathogenesis
Transmission of rabies virus by bite from infected mammal
Reservoir
United States: Bats (most common), raccoons, skunks, foxes
Developing world: Dogs
Clinical features
Encephalitic
Hydrophobia
Aerophobia
Pharyngeal spasm, spastic paralysis
Agitation
Paralytic
Ascending flaccid paralysis
Postexposure prophylaxis
Rabies immune globulin & rabies vaccine immediately after exposure to high-risk wild animal
Prognosis
Coma, respiratory failure & death within weeks
Cat scratch
👾
Bartonella henselae (Gram -ve  bacilli)
Can be transmitted by cat scratch/bite
Clx
Papule at scratch/bite site
Regional LN
± Fever of unknown origin ( ≥14 days)
Dx
Usually Clx
± Serology
Tx
Generally self-limiting
Azithromycin

Viral Infections

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Parvovirus B19
S/S
 It can presents in 3 different forms
·       Erythema infectiosum (fifth disease): Fever,  nausea & “slapped cheek” rash (more in babies)
·       Acute, symmetric arthralgia/arthritis: Hands, wrists, knees & feet (resembles RA)
·       Transient pure red cell aplasia; aplastic crisis in patients with underlying hematologic disease (sickle cell)
Dx
Acute infection
-B19 lgM antibodies in immunocompetent patients
-NAAT for B19 DNA in immunocompromised patients
Previous infection
-B19 lgG antibodies (documents immunity)
-Reactivation of previous infection: NAAT for 819 DNA
   
Varicella infection
Clx
Air transmission
2 week incubation
Prodrome (eg, fever, malaise)
Maculopapular rash followed by successive  “crops” of vesicles
Tx
Usually self-limiting
Antiviral therapy for immunocompromised or
complicated disease (Cerebellar ataxia, pneumonia)
PPx
2 doses of varicella-zoster virus vaccine (ages 1 & 4)
Herpes zoster (shingles)
Path
·       Reactivation of VZV from sensory nerve ganglion
Clx
·       Prodromal phase: itching, tingling, burning in dermatomal distribution
·       Rash: grouped papules & vesicles on erythematous base; ulceration & crusting; acute neuritic pain
·       Postherpetic neuralgia: persistent neuritic pain >4 months after rash onset
Tx
·       Antiviral therapy: acyclovir, valacyclovir, famciclovir
·       Postherpetic neuralgia: TCA pregabalin, gabapentin
Herpes Zoster Oticus (Ramsay Hunt Syndrome)
Path
VZV reactivation of CN8
Sx
Painful Vesicles in auditory canal + ipsilateral Facial paralysis
– they can develop vestibular sx
Tx
Valacyclovir
Classification of herpes zoster pain
Pain
time
(from rash onset)
Tx
Acute herpetic neuralgia
<1 month
NSAlDs, analgesics
Subacute herpetic neuralgia
1-4 months
NSAlDs, analgesics
Postherpetic neuralgia
> 4 months
TCA,
gabapentin,
pregabalin
Chikungunya fever
#
Tropical parts of South America, Africa & Asia
Aedes mosquito (also transmits dengue & Zika)
Sx
·       Incubation period: 3-7 days
·       High fevers
·       Severe polyarthralgias (almost always present)
·       Headache, myalgias, conjunctivitis,
·       Maculopapular rash
·       Lymphopenia, thrombocytopenia, transaminitis
Tx
Supportive (Resolves w/i 10 days)
Chronic arthralgias/arthritis occurs in >50% (may need MTX)
Infectious Mononucleosis (EBV)
Cix
Fever
Tonsillitis/pharyngitis ± exudates
Tender Cervical LN
 ± HSM
 ± Rash after amoxicillin
Dx
⊕ heterophile antibody (Monospot) test (25% false-negative rate during 1st week of illness)
Atypical lymphocytosis
Transient hepatitis
Tx
Supportive
Avoid sports for ≥3 weeks (contact sports ≥4 weeks) due to the risk of splenic rupture
Comp
Acute AW obstruction
AIHA & ↓platelets
Splenic rupture (inc risk w sport)
Nasopharyngeal carcinoma is associated with the reactivation of EBV, Asians
Symptoms:
– nasal congestion with epistaxis,
– headaches,
– CN palsies,
– otitis media.
Mosquito-borne dengue fever
Present with fever and headache.
Symptoms typically develop 4-7 days following the mosquito bite
Classically include:
Marked muscle and joint pains, Retroorbital pain, Rash, leukopenia (diagnostically useful).
Can present w/ HEMORRHAGIC dengue fever (Bleeding from nose).

UTI/Pyelonephritis

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Urethritis
·       STD
·       Discharge
·       Dx: NAAT
·       Tx: Azithromycin + Ceftriaxone
·       F/U: HIV
Asx Bacteuria
·       E.coli / GBS
·       If preg + Asx bactiuria –> Amoxicillin –(allergic?)–> Nitrof
Cystitis
·       E.coli
·       choose either: TMP-SMX / Nitrof / Fibronycin
Pyelonephritis
·       IP (really sick): IV ceftriaxone
·       OP (young and okay): ORAL FQ Ciprofloxacin (10 ds)
·       Change to oral w/ improvement of sx in 48 h
Perinephric Abscess
·       Dx CT / US
·       drainage + pyelo Abx (14 ds)

Urinary tract infection
👾
E coli most common cause
Clx
Cystitis
Dysuria, frequency, urgency, hematuria, suprapubic pain.
Pyelonephritis
Fever >38c, chills, flank pain, costovertebral angle, tenderness & nausea/vomiting,
+/- cystitis symptoms
Dx
Urinalysis & urine culture
Tx
Antibiotics
 Acute pyelonephritis
Uncomplicated
• Otherwise healthy, nonpregnant
• Primarily Escherichia coli
• oral Fq, TMP-SMX
• IV antibiotics if vomiting, elderly, septic
Complicated
• Diabetes,
• urinary obstruction/instrumentation,
• renal failure,
• immunosuppression, hospital-acquired
• ↑ Risk of antibiotic resistance/treatment failure
• IV fluoroquinolone. aminoglycoside. extended spectrum beta-
lactam/cephalosporin
 Acute bacterial prostatitis
Path
·       Intraprostatic reflux of pathogens in urine
·       Gram-negative bacilli (Escherichia coli —75%)
Sx
·       Flu-like illness (eg, fever, chills, malaise, myalgia)
·       Lower urinary symptoms (eg, dysuria, urine retention, pelvic pain)
Dx
·       Digital rectal exam — tender, swollen prostate
·       Urine cx
Tx
·       6 weeks of TMP-SMX or FQ
Comp
·       Sepsis: Bacteremia/systemic spread
·       Abscess: Prostatic abscess
·       Chronic prostatitis
 Chronic Bacterial Prostatitis
#
Young & middle-aged men
⤴️ Risk with diabetes, smoking, urinary tract procedure
Path
Coliforms enter from urethra via intraprostatic reflux → Escherichia coli causes >75% of cases
Sx
Recurrent UTIs (with the same organism)
Prostatic tenderness and swelling
Pain with ejaculation
History of Abx Tx → Transient improvement
Dx
Pyuria and bacteriuria on UA
Bacteria in prostatic fluid > bacteria in urine
Tx
CIPROFLOXACIN for 4-6 weeks
 Chronic prostatitis / Chronic pelvic pain syndrome
 Sx
·       Pain in pelvis, perineum, genitalia
·       Irritative voiding sx (eg, urgency, hesitancy)
·       Hematospermia, pain w/ ejaculation
Dx
·       Mild prostate tenderness
·       Sterile urine Cx
Tx 
·       Alpha blockers (eg, tamsulosin)
·       Abx (eg, ciprofloxacin), especially if hx of UTI
·       5a-reductase inhibitors (eg, finasteride)

TB

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PPD/TST
Tx if:
≥5
·       HIV / immunosuppressed
·       Recent contacts of known TB case
≥ 10 mm
·       Immigrants
·       IV drug users
·       Residents & employees Of high-risk settings (eg, prisons, nursing homes, hospitals, homeless
·       shelters)
·       Mycobacteriology laboratory personnel
·       Higher risk for TB reactivation (eg, DM, leukemia, ESRD, chronic malabsorption syndromes)
≥ 15 mm
All Of the above plus healthy individuals
Isoniazid (INH) SE:
Severe INH hepatitis and a much milder hepatotoxicity.
How does SEVERE hepatitis presents? What to do about it?
Isoniazid hepatitis presents with clinical manifestations that are similar to those seen with viral hepatitis.
If signs and symptoms of INH hepatitis are observed, the drug should be discontinued immediately.
What’s subclinical hepatic injury?
mild, subclinical hepatic injury demonstrated only by minor elevations in serum aminotransferases (typically < 100 IU/L).

Skin Infections

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Hypersensitivity reactions
Type I (immediate)
IgE-mediated
·       Anaphylaxis
·       Urticaria
Type II (cytotoxic)
lgG & lgM autoantibody-mediated
·       Autoimmune hemolytic anemia
·       Goodpasture syndrome
Type III    (immune complex)
Antibody-antigen complex deposition
·       Serum sickness
·       Poststreptococcal glomerulonephritis
·       Lupus nephritis
Type IV  (delayed type)
T cell- & macrophage-mediated
·       Contact dermatitis
·       Tuberculin skin test
Impetigo
Type
Non– Bullous
Bullous
👾
·       Staphylococcus aureus
·       Group A Streptococcus
(S pyogenes)
·       S aureus
Clx
·       Painful non-pruritic pustules
·       Honey-crusted lesions
·       Rapidly enlarging flaccid bullae with yellow fluid
·       Collarette of scale at periphery of ruptured lesions
Tx
·       Limited skin involvement: Topical antibiotics (mupirocin)
·       Extensive skin involvement: Oral antibiotics (eg, cephalexin, dicloxacillin, clindamycin)
Necrotizing Fasciitis
👾
·       Streptococcus Pyogenes (group A streptococci)
·       Staphylococcus aureus
·       Clostridium perfringens
·       Polymicrobial
Area
Most commonly involves extremities & perineal region
Clx
·       Erythema of overlying skin
·       Swelling & edema
·       Pain out of proportion to examination findings
·       Systemic sx (fever & hypotension)
Tx
Requires surgical debridement & broad-spectrum Abx
Toxic Shock Syndrome
Fever + Hypotension + Desquamation rash + Multi-organ failure
Fever >38.9
Hypotension with systolic BP ≤ 90
Diffuse macular erythroderma
Skin desquamation, including palms & soles, 1-2 weeks after illness onset
·       Gl (vomiting &/or diarrhea)
·       Muscular (severe myalgias or elevated creatine kinase)
·       Mucous membrane hyperemia
·       Renal (BUN or serum creatinine >1-2x upper limit of normal)
·       Hematologic (platelets <100,OOO/mm3)
·       Liver (ALT, AST & total bilirubin >2x upper limit of normal)
·       Central nervous system (altered mentation without focal neurological signs)
Cervicofacial Actinomyces
RF
·       Dental infections & trauma (extraction)
·       Immunosuppression / DM
Clx
·       Upper/lower jaw (mandible)
·       Slowly progressive, nonpainful, indurated mass
·       Sinus tracts with sulfur granules
Dx
FNA / Cx (takes up to 14 days)
Tx
Penicillin 2-6 months
Tinea versicolor (pityriasis versicolor)
👾
·       Malassezia globosa/furfur 
Clx
Hypopigmented/hyperpigmented lesions (face in children, trunk & upper extremities in adolescents & adults)
Dx
KOH shows hyphae & yeast cells in a “spaghetti & meatballs” pattern
Tx
·       Topical ketoconazole, terbinafine, or selenium sulfide
Tinea corporis (ringworm)
RF
Athletes
⊕ PMHx contact w/ infected animals (rodents)
Clx
Scaly, erythematous, pruritic patch with centrifugal spread
Subsequent central clearing with raised annular border
Tx
Localized → Topical clotrimazole
Extensive → Oral erbinafine / griseofulvin
Scabies
·       Sx: itchy fingers (webs of hands)
·       Dx: Scrape
·       Tx: Permithirine
Lice:
·       Sx: itchy head
·       Dx: see the lice + eggs
·       Tx: Permithirine
Pinworm
·       Sx: itchy butt
·       Dx: Tape
·       Tx: Albendazole

Sexually-Transmitted Infections

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Pt presents w/ a lesion on genitals 👨🏻/👩🏻
Painful
HSV
·       Vesicles or ulcers on erythematous base
·       Mild LN
Haemophilus ducreyi (chancroid)
·       Larger, deep ulcers with gray/yellow exudate
·       Well-demarcated borders & soft, friable base
·       Severe LN that may suppurate
Painless
Treponema pallidum (syphilis)
·       Single ulcer (chancre)
·       Regular borders & hard base
Chlamydia trachomatis serovars L1-L3 (lymphogranuloma venereum)
·       Small, shallow ulcers (often missed)
·       Can progress to painful, fluctuant adenitis (buboes)
Dx
Tx
Syphilis
·       Dark-field microscopy
·       VDRL or RPR (75% sensitive in primary syphilis) FTA or MHA-TP (confirmatory)
·       Single dose of intramuscular benzathine penicillin
·       Doxycycline if penicillin allergic
·       Primary = Chancre, Dark Field Microscopy, One dose of penicillin
·       Early-Latent (secondary part) = No Chancre, RPR, FTA-Abs, One dose of penicillin
·       Late-Latent (secondary part b) = No chancre, RPR, FTA-Abs, 3 doses of penicillin
·       Tertiary = Neuro symptoms, 14 days of penicillin
Chancroid (Haemophilus ducreyi)
Stain and culture
Azithromycin (single dose)
Lymphogranuloma venereum
(chlamydia L1-L3)
·       Complement fixation titers in blood
·       NAAT
Doxycycline
Herpes simplex
·       1˚ PCR is the most accurate.
·       Viral culture and Tzanck smear are alternative, but lacks sensitivity
Acyclovir, valacyclovir, famciclovir Foscarnet for acyclovir-resistant herpes
Gonoccoccus / Chlamydia
Urethritis
S/S
·       urethral discharge + urinary sx
·       Fever
Dx
1˚ Best initial? Gram stain / NAAT
Tx
If you don’t know: 2 drug (Ceftriaxone + Azithromycin)
If gonorrhea: 2 Drugs (Ceftriaxone + Azithromycin)
if Chalmydia: Azithromycin
Chlamydia & gonorrhea in women 👩🏻
RF
Age <25
High-risk sexual behavior
S/S
Asymptomatic (rnost common)
Cervicitis
Urethritis
Perihepatitis (Fitz-Hugh-Curtis syndrome)
Dx
Nucleic acid amplification testing
Tx
Empiric: Azithromycin + ceftriaxone
Confirmed chlamydia: Azithromycin
Confirmed gonorrhea: Azithromycin + ceftriaxone
Comp
Pelvic inflammatory disease
Ectopic pregnancy
Infertility
 Urethritis in men
👾
Neisseria gonorrhoeae (MCC)
Chlamydia trachomatis
Mycoplasma genitalium
Clx
Dysuria
Discharge
Urgency
Inc Voiding frequency
Dx
UA
Gram stain & Cx
NAAT
Tx
Azithromycin OR doxycycline
PLUS ceftriaxone if gonococcus suspected or not ruled out
Disseminated Gonococcal Infection
Clx
• Monoarthritis (septic)
and / or
• Triad of ∆:
   • Tenosynovitis,
   • Dermatitis (erythematous papules & pustules),
   • Asymmetric migratory polyarthralgias
Dx
• Blood Cx (may be Θ)
• Arthrocentesis (synovial fluid analysis): Inflammatory with Nø predominance + Do Gram stain & culture or NAAT
• Cx or NAAT Of urethra, cervix, pharynx, rectum
Tx
• IV ceftriaxone, switch to oral (cefixime) when clinically improved
• Empiric azithromycin OR doxycycline for chlamydial
• Joint drainage for purulent arthritis
Pelvic Inflammatory Disease
S/S
·       Fever
·       Motion tenderness
Dx
·       1˚  R/O Pregnancy ✳️ ✳️ ✳️
·       2˚ Cervical swab for culture, DNA probe, or NAAT
·       The most accurate test for PID is laparoscopy
Tx
·       IP: Cefoxitin + doxycycline
·       OP: Ceftriaxone + doxycycline
·       Patients with anaphylaxis to penicillin: levofloxacin and metronidazole
  Syphilis
Syphilis
1˚
 Painless chancre
2˚
·       Diffuse rash (palms & soles)
·       LN (epitrochlear)
·       Condyloma LATA (late)
·       Oral lesions
·       Hepatitis
Latent
·       Asx
3˚
·       CNS (tabes dorsalis, dementia)
·       CVS (aortic aneurysm/insufficiency)
·       Cutaneous (gummas)
·       HIV pts develop neurosyphilis faster
Features of Tabes Dorsalis (3ry Syphilis)
#
·       HIV pts develop neurosyphilis faster
Path
·       Treponema pallidum spirochetes directly damage the dorsal sensory roots
·       Secondary degeneration Of the dorsal columns
Clx
·       Sensory ataxia
·       Shooting pains
·       Neurogenic urinary incontinence
·       Associated with Argyll Robertson pupils (No response to light – but accomodate)
Syphilis – diagnostic serology
Nontreponemal
(RPR, VDRL)
·       Antibody to cardiolipin-cholesterol-lecithin antigen
·       Quantitative (titers)
·       Possible negative result in early infection
·       Decrease in titers confirms treatment
Treponemal
(FTA-ABS,
TP-EIA)
·       Antibody to treponemal antigens
·       Qualitative (reactive/nonreactive)
·       Greater sensitivity in early infection
·       ⊕ even after tx
·       Desensitization is costly and time consuming and reserved primarily for situations in which:
1. alternate treatments are ineffective (CNS Syphilis, multiple treatment failures)
2. Alternative is Contraindicated (Pregnancy).
Syphilis Tx
1st-line
Alternate
1˚ (chancre)
Penicillin G (IM) x 1 dose
Doxycycline x 14 days
2˚ (diffuse rash)
Penicillin G (IM)x 1 dose
Doxycycline x 14 days
Latent (Asx)
Penicillin G (IM) x 3 doses
Doxycycline x 28 days
3˚ (CV, gummas)
Penicillin G (IM) x 14 days
Ceftriaxone x 14 days
Penicillin G (IV) is recommended for neurosyphilis (desensitization if penicillin allergy).
  
Jarisch-Herxheimer reaction
#
·       6-48 hours after initiating treatment for syphilis (most commonly primary or secondary)
·       May also be seen with treatment of other spirochete  diseases (eg, Lyme disease, leptospirosis)
Clx
·       Acute onset of fevers, chills, myalgias
·       Rash progression in secondary syphilis
Tx
·       Supportive (IV fluids, acetaminophen, NSAlDs)
·       Typically self-limiting within 48 hours of onset

Sepsis

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 Sepsis
Def
·       a dysregulated host response to infection that results in organ dysfunction
·       can go to septic shock
RF
·       admission to ICU
·       bacteremia
·       advanced age (≥ 65 years of age)
·       immunosuppression
·       diabetes
·       obesity
·       malignancy
S/S
·       Fever
·       Sx of infection source
·       Sx of organ failure (liver / kidney)
·       AMS + RR >30 + BP ⤵️
·       Warm flushed skin
Dx
·       leukocytosis or leukopenia
·       elevated C-reactie protein
·       arterial hypoxemia
·       acute oliguria and worsening creatinine
·       elevated lactate
·       respiratory alkalosis with a metabolic acidosis 
·       thrombocytopenia
·       hyperbilirubinemia
Tx
·       ICU Admission
·       Remove source of infection if found (Catheter)
·       IVF
·       IV Abx – administered preferably within the first hour once a presumed diagnosis of sepsis has been made
Comp
·       DIC
·       Death
·       Multi-organ failure

Pneumonia

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Distinguishing features of common upper respiratory illnesses
Viral URTI
Influenza
Streptococcal pharyngitis
Onset
Slow, stepwise, migratory, or evolving
Abrupt & often dramatic
Variable
Sx
Rhinorrhea, coryza, sneezing, mild pharyngitis
Usually mild
Predominantly pharyngeal symptoms
Systemic Sx
Usually mild
Prominent with possible high fever, myalgias, headache
Variable with possible fever & myalgias
PEx
Nasal edema with normal or slightly erythematous pharynx
Variable but often unremarkable
Pharyngeal erythema, tonsillar hypertrophy & exudates, tender cervical lymph nodes
Pneumonia
S/S
Fever + Cough
CURB-65
o   Confusion
o   Respiratory rate >30/min
o   BUN >7 mmol/L or 20 mg/dL
o   Room air PaO2 <60 mmHg
o   O2 saturation <90% on room air
o   Blood pressure <90 mmHg systolic or <60 mmHg diastolic
o   Age >65
Tx
CAP
Either:
1.     Azithromycin + Ceftriaxone
2.     Fq
HCAP/VAP
·       MRSA: Vancomycin
·       Pseudomonas:
·       Pip-tazo
·       carbapenem
PCP
TMP-SMX +/- corticosteroids
Empiric Tx of CAP
OP
·       Macrolide or doxycycline (healthy)
·       Fluoroquinolone’ or beta-lactam + macrolide (comorbidities)
IP (non-ICU)
·       Fluoroquinolone’ (IV)
·       Beta-lactam + macrolide (IV)
IP (ICU)
·       Beta-lactam + macrolide (IV)
·       Beta-lactam + fluoroquinolone’ (IV)
Parapneumonic effusion
Uncomplicated
Complicated
?
Sterile exudate in pleural space
Bacterial invasion of pleural space
(Usually bigger)
Fluid Analysis
• pH >7.2
• Glucose 260 mg/dL
• WBC <50,OOO/mm3
·       pH <7.2
·       Glucose <60 mg/dL
·       WBC > 50,OOO/mm3
cx
⊖
(low bacterial #)
Tx
Abx
Abx + drainage
Legionella pneumonia
Source
Contaminated water
S/S
·       Fever >38.8
·       Relative bradycardia
·       GI (diarrhea, vomiting, cramps)
·       Pulmonary sx delayed
Dx
·       Hyponatremia
·       CXR – Patchy unilobar or interstitial infiltrates
·       Sputum Gram stain – PMNs, few/no organisms
·       Urine Legionella antigen
Tx
Respiratory FQ or newer macrolides
Mycoplasma pneumonia
#
·       Respiratory droplets
·       Young (school, military)
·       Fall or winter
Clx
·       Indolent headache, malaise, fever, persistent dry cough
·       Pharyngitis (nonexudative)
·       Macular/vesicular rash
Dx
·       CBC: normal WBC / Hemolytic anemia (cold agglutinins)
·       CXR: b/ Interstitial infiltrate
Tx
·       Usually empiric
·       Macrolide or respiratory Fq
Lung abscess
↑ Risk in?
·       Aspiration pneumonia (most common)
·       Dysphagia, substance abuse (alcohol)
·       Gingival disease (bad teeth)
·       Oropharynx anaerobes
Sx
·       Indolent (2 weeks) Sx
·       Fever, night sweats, weight loss
·       Cough with putrid sputum
·       Hyponatremia
Dx
·       Cavitary infiltrates with air-fluid levels (can happen in upper lobes)
·       Do we need to do cx? No, rarely useful
Tx
Clindamycin
TB
Invasive Aspergillus
Chronic Pulmonary Asperigllus
CMV Pneumonitis
Hx
Immunocompromised
immunocompromised (neutropenia, HIV)
after CAVITARY lung dz (post-TB)
Immunocompromised
S/S
·       Fever
·       SOB
·       Hemoptysis
·       Weight loss
·       Fever
·       Pleuritic chest pain
·       Hemoptysis
·       Brown Sputum
·       >3 months
·       weight loss
·       hemoptysis
·       SOB
·       Low grade Fever
·       Unproductive Cough
·       SOB
CXR
Cavitation
ⓤ UPPER LOBE Lesions
cavitary lesion w/ fungus ball (Aspirigilloma)
–
CT
Cavitation in upper/middle lobe
UNILATERAL NODULES w/ GROUND GLASS Opacity (Halo sign)
Diffuse ground glass opacities
Tx
RIPE 9 months
·      2 w of IV Voriconazole (+ capsofungin)
·      Switch to Oral Voriconazole
·       Resect asperigilloma (if possible)
·       antifungal (-azole)
Ganciclovir

Parasitic Infections

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Neurocysticercosis
#
·       Taenia solium (pork tapeworm) eggs
·       Fecal-oral human transmission
·       Central & South America, sub-Saharan Africa, Asia
Clx
·       Prolonged incubation (months to years)
·       Seizures
·       ICH (headache, vomiting, AMS)
Dx
·       CT/MRI — cysts (hypodense, enhancement/edema, or calcified)
Tx
·       Seizure/lCH management
·       Antiparasitic therapy (albendazole)
·       Corticosteroids
Ascariasis
Clx
can present with intestinal symptoms and eosinophilia,
SBO + Eø / Abd sx+ Eø
but more often has a lung phase with nonproductive cough followed by an asymptomatic intestinal phase.
Ascariasis can also present with the worms obstructing the small bowel or bile ducts.
Clinical features of Trichinellosis
life cycle
·       Ingestion of undercooked meat (usually pork)
·       More endemic in Mexico, China, Thailand, parts of central Europe & Argentina
·       Gastric acid releases larvae (within 1st week of ingestion)  that invade small intestine & develop into worms
·       Female worms release larvae (up to 4 weeks later) that migrate & encyst in striated muscle
Clx
·       Intestinal stage (within 1 week of ingestion)
Can be asymptomatic or include abdominal pain, nausea, vomiting & diarrhea
·       Muscle stage (up to 4 weeks after ingestion)
Myositis
Fever, subungual splinter hemorrhages
Periorbital edema
Eosinophilia (usually >20%) with possible elevated creatinine kinase & leukocytosis
Malaria
Path
Transmission of Plasmodium falciparum, P vivax, P ovate, or P malariae parasites by the bite of an infected Anopheles mosquito
Clx
·       Nonspecific malaise, headache, nausea, vomiting, abdominal pain, diarrhea, myalgia, pallor, jaundice, petechiae, hepatosplenomegaly.
·       Periodic febrile paroxysms
Comp
Children: SZ, coma, hypoglycemia, metabolic acidosis
Adults: Jaundice, acute renal failure, acute pulmonary edema
Dx
Thin & thick peripheral blood smears
PPx
·       Antimalarial drugs
o   Atovaquone-proguanil
o   Doxycycline
o   Mefloquine
o   Chloroquine
·       Hydroxychloroquine
·       Insecticide-treated nets
·       Household insecticide residual spraying
Babesiosis
#
·       Babesia microti
·       Ixodes scapularis tick bite (Lyme disease & HGA)
·       Northeastern United States
Clx
·       Fever, fatigue, myalgias, headache (flu-like symptoms)
·       If severe: ARDS, CHF , DIC, splenic rupture
·       Anemia, thrombocytopenia, inc bilirubin/LDH/LFTs
Dx
·       Thin blood smear – intraerythrocytic rings (“Maltese cross”)
Tx
·       Atovaquone + azithromycin
·       Quinine + clindamycin (if severe)
Enterobius vermicularis (pinworm)
Sx
Perianal pruritus, especially at night
Dx
Eggs on tape test
Tx
Pyrantel pamoate OR albendazole
Tx pts & all household contacts
Cutaneous larva migrans
#
·       Hookworm larvae
o   Dog (Ancylostoma caninum) or cat (A braziliense)
·       Humans are incidental hosts
·       Barefoot contact with contaminated sand or soil
Clx
·       Primarily lower extremity
·       Cutaneous (deeper infection rare)
·       Erythematous, pruritic papule at site of entry
·       Intensely pruritic, migrating, serpiginous, reddish-brown tracks
Dx
·       History and clinical findings
·       Eosinophils usually normal
Tx
Antihelmintic (eg, ivermectin)