Systemic Infectious Disorders Flashcards
FROM JANE mnemonic for endocarditis
Fever Roth spots Osler nodes Murmur Janeway lesions - embolic showering to skin Anemia Nail bed hemorrhage Emboli (peripheral cavitating pulmonary nodules)
Types of presentations of tularemia
- Ulceroglandular disease (most common): ulcerated skin, regional lymphadenopathy, fever
- Glandular tularemia (2nd most common): regional lymphadenopathy without skin lesion
- Oculoglandualr: Conjunctivitis with preauricular adenopathy
- Oropharyngeal: Severe pharyngitis with cervical lymphadenitis
- Typhoidal: Fever, chills, GI sx, no skin lesions
- Pulmonary: Fever, chills, nonproductive cough, SOB
Tx for tularemia
Streptomycin
Mononucleosis infects which cells leading to widespread proliferation of disease?
B cells
T cells fight the infection
Lesser known clinical presentation of RMSF
Known:
- Fever, muscle aches, malaise, rash typically maculopapular and blanching at first and becomes petechial
Late:
- Meningitis, renal failure, respiratory failure, myocarditis
Lab findings of RMSF
- Isolated thrombocytopenia
- Mild transaminitis
- Hyponatremia
Dx by immunofluorescent or antibody testing
What is Rumpel-Leede phenomenon
In RMSF, petechiae formation after blood pressure cuff inflation
Which STIs have high rate of cotransmission with HIV?
Disorders characterized by genital ulcers (syphilis, herpes, chancroid, lymphogranuloma venereum, granuloma inguinale)
Presentation and causative agent for lymphogranuloma venereum
Painless small, shallow painless ulcer or vesicle
Tender inguinal/femoral lymphadenopathy
Chlamydia trachomatis #965851
Presentation and causative agent for granuloma inguinale
Painless, beefy red ulcer with painless papule
Klebsiella granulomatis #965851
Presentation and causative agent for Syphilis
Painless penile chancre, indurated ulcer
Treponema pallidum #965851
Presentation and causative agent for Chancroid
Multiple painful papules that ulcerate and inguinal bubo
Haemophilus ducreyi #965851
Presentation and causative agent for genital herpes
Shallow, tender, painful lesions
HSV #965851
Best way to remove a tick
Grab close to tick’s head with forceps and pull upward
Classic infections that cause pulse-temperature dissociation (expected tachycardic HR based on temp is not seen) - Faget sign
- Typhoid
- Legionella
- Mycoplasma
- Yellow fever (flavivirus)
- Tularemia
- Brucellosis
- Colorado tick fever (Coltivirus)
Tx of choice for typhoid?
Rehydration and fluoroquinolone
Location of ulcers between hand, foot, mouth and herpangina
Hand, foot, mouth: anterior such as tongue, buccal mucosa, palate, and gingiva
Herpangina: posterior oral cavity
T/F: Onychomadesis (shredding of the proximal nail) is a benign complication of hand, foot, and mouth disease occurring 7-10 days after presentation of other symptoms
True
MOA of rifampin
Inhibits bacterial RNA synthesis by binding to beta subunit of DNA-dependent RNA polymerase, blocking RNA transcription
Uses for rifampin
- Meningococcal prophylaxis
- TB, active and latent
- Anaplasmosis
- Brain abscess
- Brucellosis
- Cholestatic pruritus
- Endocarditis (prosthetic valve)
- Leprosy
- Osteomyelitis
Adverse effects of rifampin
- Hepatotoxicity
- Skin rash
- Abdominal cramps
- Diarrhea
- Red/orange discoloration to tears and urine
Two alternatives to rifampin for post-exposure prophylaxis from meningococcemia?
Ceftriaxone and ciprofloxacin
Clinical presentation of hantavirus
Initial prodrome flu-like sx with myalgias, fever, n/v, malaise, dizziness 1-2 weeks post exposure
Tachypnea and tachycardia and cxr with bilateral pulmonary edema
Can progress to respiratory distress and to respiratory failure and postural hypotension can progress to cardiogenic shock
CBC may show thrombocytopenia
Where are most reported cases of Hanta virus in the United States?
Western USA
Kaposi sarcoma is most commonly caused by what virus?
HHV-8 and in patients with CD4 <200
Treatment for Entamoeba histolytica
Metronidazole (or tinidazole, nitazoxanide) and paromomycin (luminal agent that follows metronidazole)
Determining type of meningitis by LP results
Q141663
Symptoms of symptomatic hyperleukocytosis
Pulm: - Shortness of breath - Hypoxia Neuro: - Headache - Dizziness - Gait instability - Confusion - Coma
Less common:
- ECG signs of ischemia
- Renal insufficiency
- Priapism
- Acute limb ischemia
- Bowel infarction
Tx of symptomatic hyperleukocytosis
- Contact oncology for emergency induction chemotherapy
- Abx for possible concomitant serious infection
- Fluid bolus
- hydroxyurea, allopurinol, leukapheresis
- ICU dispo
Lab abnormalities in leukostasis (symptomatic hyperleukocytosis)
- Arterial pO2 can be falsely decreased bc of enhanced metabolic activity of malignant cells
- Plt count may be overestimated
- Tumor lysis syndrome
- DIC
Metabolic complications associated with tumor lysis syndrome?
- Hyperuricemia
- Hyperkalemia
- Hyperphosphatemia
- Hypocalcemia
What is the leading cause of non-solid organ cancer-related death?
Non-Hodgkin Lymphoma
Leading cause of cancer-related death overall?
Adenocarcinoma of the lung
Only third-generation cephalosporin with anti-pseudomonal coverage
Ceftazidime
What disease can toxic shock syndrome be mistaken for?
Kawasaki (both with conjunctival hyperemia and a strawberry tongue), but TSS has much more acute onset
Tx of toxic shock syndrome
Nafcillin, oxacillin or cefazolin plus clinda
Oral lesions in hand foot mouth disease occur where?
Anterior oral cavity (most commonly on tongue and buccal mucosa; also hard palate, gingivae, lips)
Herpangina vs. hand, foot, mouth
Herpangina - ulcers of posterior oral cavity
Hand, foot, mouth - ulcers of anterior oral cavity
Three rare complications of hand, foot, mouth
- Myocarditis
- Pneumonia
- Meningoencephalitis
Oral abx with MRSA coverage
- Doxycycline
- Bactrim
- Clindamycin
- Linezolid
Most common pathogens implicated in erysipelas?
Beta-hemolytic streptococci
Clues necrotizing fasciitis is due to Clostridial infection
- Trauma (C. perfringens)
- Dirty wound and lack of appropriate medical resources
- Spores found in soil and marine environments
- Crepitus on exam or air in tissues on plain films
- Spontaneous (C. septicum)
Presentation of sporotrichosis
Characteristic rash begins with an ulcer or papule (innocuous puncture wound from rose bush thorn) and then spreads proximally along lymphatic channels with skip lesions of suppurating subcutaneous nodules
Tx for sporotrichosis
3-6 months of itraconazole
(Amphotericin B for severe, disseminated)
Require admission if disseminated or involves joints, bones, or tendons
What mosquito transmits malaria?
Anopheles
Malaria presentation
Nonspecific fever, malaise, myalgias
Hepatosplenomegaly, generalized abdominal tenderness
Can progress to seizures, coma, acute respiratory failure, renal failure, hypoglycemia, death
If lymphadenopathy or rash think alternative or additional diagnosis
What is the most severe species for malaria?
P. Falciparum
What disease is transmitted by Aedes aegypti mosquito?
Yellow fever
Also chikungunya, dengue, Zika
What can mimic tetanus?
Strychnine poisoning
Presentation of tetanus?
Trismus (lockjaw), rigidity and spasms of muscles
Tx for tetanus
Benzos, metronidazole, TIG, immunization
What test is most sensitive for TB?
TB skin test or Mantoux test or PPD test
Type IV hypersensitivity reaction
Positive TB skin tests based on population
> 5mm: HIV+, recent contact with an active TB patient, nodular or fibrotic changes on CXR, organ transplant
> 10mm: Recent arrivals (<5 yrs) from high-prevalence countries, IVDU, resident/employee of high-risk congregate settings, comorbid conditions, children <4 y/o, infants, children and adolescents exposed to high-risk categories
> 15mm: Persons with no known risk factors for TB
What is the clinical relevance of CD4 count 200-500 in HIV
- Thrush
- Pneumonia
- Zoster
- Hairy leukoplakia
- B-cell lymphoma
- Hodgkin disease
- Kaposi sarcoma
- Tuberculosis
What is the clinical relevance of CD4 <200 in HIV
- Esophageal candidiasis
- CMV retinitis
- PCP
- HIV encephalopathy
- Disseminated histoplasmosis
- Salmonella septicemia
What is the clinical relevance of CD4 Count <50 in HIV?
- Disseminated CMV
- Mycoplasma avium
Toxoplasma gondii vs. primary CNS lymphoma vs. PML in HIV
Toxoplasma gondii : ring-enhancing intracranial lesions + focal neurologic deficits
Primary CNS lymphoma: ring-enhancing intracranial lesions + AMS
PML: focal neurologic deficits, non-enhancing white matter lesions
What sites in the CNS does rabies show predilection for?
Pons and medulla
Symptoms of rabies
Viral prodrome with headache, fever, rhinorrhea, sore throat, myalgias and vomiting
Encephalitis with agitation, hallucinations, ataxia, weakness, seizures
Aerophobia (fear of air in motion) and severe hydrophobia (violent diaphragmatic contraction while drinking water and a strong protective gag reflex)
Rabies postexposure prophylaxis
Not previously vaccinated: rabies immune globulin 20 U/kg infiltrate around wound(s) and vaccine 1mL IM days 0,3,7,14 (add day 28 if immunocompromised)
Previously vaccinated: RIG not indicated; vaccine 1mL IM days 0,3 (add all other days if immunocompromised)
Which gram-negative organisms which are difficult to culture can cause endocarditis?
HACEK
- haemophilus
- actinobacillus
- cardiobacterium
- eikenella
- kingella
Possible CXR findings in histoplasmosis
In over 1/2 of cases CXR will be normal
Other potential findings include perihilar adenopathy or mild diffuse infiltrates
How is definitive diagnosis made of histoplasmosis
Antigen testing
Tx of histoplasmosis
Oral itraconazole or amphotericin B
What are the indications for steroids in addition to antibiotics in PJP?
PaO2 <70 mm Hg or A-a gradient >35
Viruses and bacteria requiring droplet precautions
- Influenza
- Parainfluenza
- Adenovirus
- RSV
- Human metapneumovirus
- Bordetella pertussis
- N. Meningitides (first 24 hours of therapy)
- Group A strep (first 24 hours of therapy)
Viruses and bacteria requiring airborne precautions
- TB
- Measles
- Varicella-zoster
- COVID 19
Common viral cause of parotitis
Paramyxovirus
Who should oseltamivir be given to?
Greatest benefit given within 48 hrs, but can still be beneficial up to 5 days after symptom onset
Those at high risk for developing complications of influenza
- Kids <2 y/o and people >65
- Pregnancy (risk increases by trimester) and postpartum (2 weeks)
- Pulmonary disease (increases with use of corticosteroids)
- CV disease (NOT isolated HTN)
- Chronic renal insufficiency
- Morbid obesity (BMI >40)
- Cancer
- DM
- Hemoglobinopathies
- People <19 on long-term ASA
- Immunosuppression
- Residents of nursing homes and other chronic care facilities
Clostridium tetani pathophysiology
Symptoms are caused by bacterial release of exotoxin tetanospasmin which prevents the presynaptic release of the inhibitory neurotransmitters GABA and glycine
Descending tetanic spasms
Important distinction between tularemia and anthrax?
Absence of a widened mediastinum -> tularemia
Which bacterium causes bubonic plague?
Yersinia pestis
What is the recommended abx regimen for a brain abscess from an oral or sinus source?
IV metronidazole and ceftriaxone (or cefotaxime) +/- vancomycin
Upper limit of normal of retropharyngeal space at C2 and C6 (adults and peds)
C2: <5-7 mm
C6: <14 mm (peds) <22 mm (adults)
How is diagnosis of botulism confirmed?
Specialized laboratory testing for botulinum toxin in the stool
Tx should occur prior to definitive dx with botulism immune globulin as early as possible
Clinical presentation of infant botulism
- Constipation
- Weak suck, feeble cry, poor gag reflex, pooled secretions
- Generalized weakness, hypotonia, loss of head control
Descending, symmetric, flaccid paralysis
What type of infection due to Clostridium botulinum should be treated with antibiotics?
Wound - treated with penicillin G
Which appears first in neonate, conjunctivitis caused by N. Gonorrhoeae or C. Trachomatis?
N. Gonorrhoeae within first 5-7 days of birth
C. Trachomatis 5-14 days of birth
When would you prefer IV abx vs. PO abx in cellulitis
Vital sign abnormalities, rapid progression and involvement of large area of skin
Risk factors for cryptococcal meningoencephalitis
- HIV
- Chronic steroid use
- Solid organ transplantation
- Cancer (especially hematologic malignancies)
At what CD4 count are patients with HIV at increased risk of cryptococcal meningitis?
<100
Clinical presentation of leptospirosis
- Contaminated freshwater
- Abrupt onset of fever, rigors, myalgia, headache
- ***Conjunctival suffusion (redness without exudates)
- Jaundice
- Nonproductive cough
Complication = Weil Syndrome caused by circulating antibodies = progression to aseptic meningitis, renal failure, hepatitis, uveitis, rash, circulatory collapse
Tx of leptospirosis
Mild = amoxicillin or doxy Severe = IV penicillin or ceftriaxone
Clinical presentation of Leishmaniasis
Most commonly cutaneous disease
Can involve visceral organs and lead to weight loss, fever, hepatosplenomegaly, pancytopenia, and hypergammaglobulinemia
Clinical presentation of MAC
Fever, diarrhea, weight loss, anemia
Tx for MAC
Clarithromycin and ethambutol for at least 12 months (+/- rifampin)
