ID Flashcards
Beta-lactams
Inhibit cell wall synthesis by blocking peptidoglycan crosslinking
penicillins, carbapenems, aztreonam, and cephalosporins
Glycopeptide
vancomycin
- Inhibits cell wall synthesis
- only gram +
Adverse effects of Vancomycin
-which other antibiotic group has these side effects
Nephrotoxicity
Ototoxicity/vestibular toxicity
Aminoglycosides
Aminoglycosides-MOA
gentamicin
Inhibits bacterial protein synthesis by binding to the 30S subunit of the bacterial ribosome
Aminoglycosides-SE
Nephrotoxicity
Ototoxicity and vestibulotoxicity (impaired hearing and balance)
Neuromuscular blockade
Doxycycline is a
Tetracycline group of Abx
Doxycycline-MOA
Inhibits bacterial protein synthesis
Adverse effects of doxycycline
1) Hepatotoxicity
2) Deposition in bones and teeth → discolouration of teeth and inhibition of bone growth in children
3) Damage to mucous membranes (e.g., esophagitis)
4) Photosensitivity: UV light is absorbed by the drug, which releases energy to the surrounding area and damages exposed areas
erythromycin, azithromycin and clarithromycin-MOA
Inhibits bacterial protein synthesis
They are marcolides
Side effects of Macrolides
Increased intestinal motility → GI discomfort
QT-interval prolongation
Anaerobes above the diaphragm it is
Anaerobes below the diaphragm it is
Clindamycin is indicated for anaerobes above the diaphragm and metronidazole treats anaerobes below it!
Ciprofloxacin
- belongs to
- MoA
Fluoroquinolones
Inhibition of prokaryotic topoisomerase II (DNA gyrase) and topoisomerase IV
Ciprofloxacin- 2 most common side effects
Muscle ache, tendinitis, tendon rupture (especially the Achilles tendon)
QT prolongation
cotrimoxazole (TMP/SMX) = trimethoprim (TMP) + sulfamethoxazole (SMX)
MoA
Inhibition of bacterial folic acid synthesis
Infectious mononucleosis is caused by
EBV
Infectious mononucleosis-clinical features
Splenomegaly (50% of cases), fever, fatigue, malaise
Pharyngitis and/or tonsillitis (reddened, enlarged tonsils covered in pus); palatal petechiae
Bilateral cervical lymphadenopathy (especially posterior) that may become generalized and can, in severe cases, lead to airway obstruction
Abdominal pain
Possibly hepatomegaly and JAUNDICE
Maculopapular rash (similar to measles): caused by the infection itself in about 5% of cases, but is generally associated with the administration of aminopenicillin (e.g., ampicillin or amoxicillin)
Diagnostic test for Infectious mononucleosis
Monospot test: detects heterophile antibodies
Laboratory analysis: elevated LDH and liver transaminases
Peripheral smear: lymphocytosis with > 10% atypical lymphocytes
IM patient has a rash after treatment with ampicillin
Tonsillitis is an important differential diagnosis for infectious monoclueosis that is often treated with aminopenicillins (e.g., ampicillin). However, if given to a patient with IM, the patient often develops a macular erythematous rash after 5–9 days!
Treatment for IM
1) Avoid physical activity that may trigger splenic rupture (e.g., contact sports) for at least 3 weeks after the onset of symptoms.
2) Fluids (IV administration if necessary)
3) Analgesics/antipyretics (e.g., acetaminophen)
EBV associated malignancies
Burkitt lymphoma (BL), a non-Hodgkin lymphoma
Hodgkin lymphoma
Nasopharyngeal carcinoma
C.difficle infection-treatment
Metronidazole
Traveller’s diarrhoea
-caused by
Most commonly caused by enterotoxigenic Escherichia coli (ETEC)
Think of M-CENTOR to remember the Modified Centor score criteria:
M = Must be older than 3 years C = Cough absent E = Exudate on the tonsils N = Node enlargement T = Temperature elevation OR = young OR old.
DDX for sore throat/tonsilitis
Tonsillitis in infectious mononucleosis
Tonsillitis in diphtheria (diphtheritic croup)
Pharyngitis
Aphthous stomatitis
Herpangina
Herpetic pharyngotonsillitis/herpetic gingivostomatitis
Ludwig angina
Oral thrush (fungal tonsillitis
State the Suppurative complications of acute tonsilitis
Peritonsillar abscess Parapharyngeal abscess Otitis media Sinusitis Cervical lymphadenitis Mastoiditis
state the non-suppurative complications of acute tonsilitis
Rheumatic fever
Scarlet fever
Poststreptococcal glomerulonephritis
Otoscopy: tympanic membrane (TM) evaluation in AOM
Early findings
1) Retracted and hypomobile
2) Loss of light reflex
Late findings
Cartwheel TM
Red bulging TM with loss of landmarks
Tuning fork test: conductive hearing loss
Complications of AOM
1) Mastoiditis
2) Labyrinthitis–>Etiology: Inflammation spreads to the inner ear (labyrinth) through the round window
3) Peripheral facial palsy
4) Otogenic abscess
Lepto triad
Triad- Fever, jaundice and hemorrhage( in Weil’s disease, not the first presentation)
However, in 10% of cases, the disease progresses rapidly to a severe form (icterohemorrhagic leptospirosis, or Weil disease), which typically presents with a triad of jaundice, bleeding manifestations, and acute kidney injury.
Scabies worse at night?
A warm bed or bath intensifies the pruritus because the mite becomes more active. Because of the release of allergenic antigens on mite trails, pruritus occurs even in regions of the body without mites.
Intense pruritus at night
ddx for scabies
Scabies may be mistaken for eczema, especially as the topical use of glucocorticoids initially alleviates symptoms!
Treatment of choice for scabies
Drug of choice: permethrin 5% lotion
Oral ivermectin: especially indicated in large outbreaks or severe forms of scabies
General measures–> Wash all textiles (e.g., clothing and bedding)
Complications of scabies
Bacterial superinfection
Three tests you can do for dengue
- Serology Test - Dengue Antibodies IgM/IgG (to detect past infection, however not specific)
- Molecular Test - Dengue PCR/NAAT- Specific and allows to determine serotypes (DNA) however negative in past infection
- Protein Test - NS1 antigen test- Specific and sensitive however negative in past infection
- NS1 antigen testing-PCR
- Viral non-strctural protein(NS)
Why is only paracetamol recommended in dengue fever
Avoid aspirin, ibuprofen or other anti-inflammatory drugs - they increase the chance of bleeding.
Strep pneumonia- what antigen can be tested
Pneumococcal urinary antigen can also be used to presumptively confirm infection
GABHS
- predisposes you to
Group A Beta hemolytic streptococcus
Skin sores and scabies
Post streptococcal glomerulonephritis- 4 things
Haematuria
Edema
Proteinuria
Hypertension
Nephritic sydrome
Scrub typhus- rickettsial disease
- what is the latin name
- what is the treament
Orientia tsutsugamushi
- Both present with fever, headache, rash, there may be an eschar visible •Diagnosis is serlogical – Will need a convalescent serum sample.
- Treatment is with doxycycline
ID guy said which antibiotic to use
Doxycycline
don’t be afraid to use it
Syphillis and pregnancy why?
Risk of transmission is least in first trimester and greatest in the third trimester.
That why we test it in each triemster
• Intrauterine death occurs in up to 25% of untreated infections.
» Most Are In The Third Trimester
5 classical signs of dengue fever
- Headache
- fever
- arthralgia
- retro- orbital pain
- mild hepatitis
- thrombocytopenia
Rarely complicated by sudden hypotension due to massive fluid shifts or bleeding.
Diagnosis of dengue by
Diagnosis by serology: NS1 antigen, Dengue IgM and IgG.
Who gets Dengue hemorrhagic fever (DHF)
what is dengue shock sydrome(DSS)
Dengue hemorrhagic fever is more frequent in individuals who experience a repeat infection with a second serotype, especially serotype 2!
Temperature change: ranges from hypothermia to a second spike in fever
Abdominal pain, vomiting
Changes in mental status (e.g., confusion)
Hemorrhagic manifestations (e.g., petechiae, epistaxis, gingival bleeding)
Increased vascular permeability → signs of pleural effusion and/or ascites
Dengue shock syndrome (DSS): DHF + shock
Dengue hemorrhagic fever(4 criteria)
- Fever, or recent history of acute fever
- Hemorrhagic manifestations
- Low platelet count (<100 x109/L)
- Objective evidence of “leaky capillaries:
–> Elevated hematocrit (plasma leakage)
–> Ascites, pleural & other effusions
–> low albumin.
best confirming test for dengue is
Best test for confirming infection: serology (IgM, IgG)
Risk factors for GBS
• GBS colonisation in current pregnancy • GBS bacteriuria in current pregnancy • Preterm labour at less than 37+0 weeks • Previous baby with EOGBSD • ROM longer than 18 hours • Maternal temperature 38 oC or higher intrapartum or within 24 hours of birth
IAP is indicated