Crash Course TB + LRTI Flashcards
Describe the stages of TB
Primary: Initial infection, often in childhood, often asymptomatic
Latent: Suppressed, hangs around in foci
Post-primary: Reactivation of latent, often d.t. immunosuppression
Give 3 classes of common symptoms of TB
Constitutional: weight loss, fever, night sweats
Pulmonary: Productive cough, haemoptysis
Lymphadenitis: scrofula (cervical)
What is a ghon focus?
Competent immune system suppresses TB: macrophages form ball around TB = caseating granuloma
(Tuberculoma)
What is Miliary TB?
Disseminated haematogenous spread
Miliary seed appearance in lungs
What is Potts disease?
TB of the spine
Back pain
Vertebral collapse
Iliopsoas abscess
What is TB meningitis?
TB infiltration into the brain (Leptomeningeal enhancement)
Subacute meningitis- meningeal Sx but slow onset over a period of time
How does genitourinary TB present?
Sterile pyuria- leukocytes on urine dip but no organism detected
What is the gold standard investigation for active TB?
X3 sputum culture
Sputum culture on Lowenstein-Jensen media
What may be seen on imaging in TB?
CXR: upper lobe cavitation
CT: consolidation, Ghon focus
What is a faster test performed for active TB?
Sputum smear + Ziehl-Neelson stain for acid fast bacilli
(can also use auramine rhodamine stain)
What may be seen on histology in TB?
caseating granuloma (Haematoxylin + eosin stains)
What is the gold standard test for exposure to TB?
IGRA
Elispot/ Quantiferon
+ve if exposure (active or latent)
Does NOT cross react with BCG
Which TB test cannot distinguish between exposure to TB and BCG vaccine?
Tuberculin skin tests: Mantoux/ Heaf
Also requires 2 visits
What is the treatment for TB?
Rifampicin (6)
Isoniazid (6)
Pyrazinamide (2)
Ethambutol (2)
What drug should be given with Isoniazid? Why?
Pyridoxine (Vit B6)
To prevent peripheral neuropathy
What is the MOA of Rifampicin?
Inhibits RNA polymerase
What is the MOA of Isoniazid?
Decreased mycolic acid synthesis (part of cell wall)
What is the MOA of Pyrazinamide?
Unknown
What is the MOA of Ethambutol?
Decreased polymerisation of cell wall
Give 3 side effects of Rifampicin
Orange / red secretions
CYP450 induction
Raised transaminases
Give 2 side effects of Isoniazid
Peripheral neuropathy (B6 deficiency)
Hepatotoxicity
Give 2 side effects of Pyrazinamide
Hyperuricaemia
Hepatotoxicity
Give a side effect of Ethambutol
Optic neuritis
(Pain, vision loss, 1 eye)
Give 3 second line drugs for TB
Amikacin
Quinolones
Linezolid
Give 3 drugs to use in multi drug resistant TB
Quinolones
Aminoglycosides
Cycloserine
What is in the BCG vaccination?
Live attenuated M. Bovis
What drugs are used for latent TB?
Just Rifampicin + Isoniazid
Give 4 risk factors for mycobacterium TB
Travel
HIV
Close contacts
IVDU
Give 3 risk factors for non-tuberculous mycobacterium
> 65
Immunosuppression
Environmental exposure (water, soil)
What does mycobacterium leprae invade?
Schwann cells + Histiocytes
What are the 2 types of mycobacterium leprae?
PAUCIbacillary tuberculoid
MULTIbacillary lepromatous
Give 4 features of paucibacillary tuberculoid leprosy
Few skin lesions
Hairless plaques
Loss of sensation
Robust T cell response
Give 4 features of multibacillary lepromatous leprosy
Multiple skin lesions
Thickened dermis
Lion like face
Poor T cell response
Give 4 features of Mycobacterium ulcerans
Slow growing
Insect transmission/ bite
Early: painless nodules
-> Bairnsdale ulcer/ Buruli ulcer
Slow progression into ulceration + deformity
Give 4 features of mycobacterium avium (MAC)
Slow growing
Commonly found in soil, food, water
May invade bronchial tree or pre-existing bronchiectasis/ cavities (CF, COPD, Aspergillosis etc) if immunocompromised
- May cause mycobacteraemia → consider in patients with HIV + longstanding diarrhoea
Give 4 features of mycobacterium marinarum
Slow growing
Swimming pool/ aqaurium owners
Single or clusters of papules on hands
“Swimming pool granuloma”
List 3 fast growing NTM
- Mycobacterium abscessus
- Mycobacterium chelonae
- Mycobacterium fortuitum
What is Bronchitis?
Who is it most commonly seen in?
What is the typical cause?
What are the X-ray findings?
How will the patient present?
Inflammation of medium sized airways
Smokers + young kids
Viral
Minimal CXR findings
Patient not too unwell- supportive Tx
What is pneumonia?
What are the X-ray findings?
What is the typical cause?
How will the patient present?
Infection of lung parenchyma
Consolidation on CXR
Bacterial
Patients look sick
What is a lung abscess?
How does a patient present?
What is often the cause?
How is it managed?
Pus filled cavetating lesion in parenchyma
Constitutional Sx: FLAWs, swinging fever, weeks ongoing
Complication of pneumonia (consider if not responding to Abx)
Needs drainage
What is a lung empyema?
What is often the cause?
How is it managed?
Pus filled collection in a space that already exists e.g. pleural space
= Infective pleural effusion
Complication of pneumonia
Needs drainage
How is pneumonia classified?
CAP: develop in community
HAP: develop >48h after hospital admission
VAP: develop on ventilator
What is the diagnosis? What can be seen here?
Bronchitis
Thickening of central bronchi
What is the diagnosis? What can be seen here?
Pneumonia
Right middle lobe consolidation
What is the diagnosis? What can be seen here?
Empyema
Looks like pleural effusion- loss of costophrenic angles + meniscus on top
What is the diagnosis? What can be seen here?
Abscess
Well circumscribed lesion within parenchyma
Air spaces within
Cavity walled off with fluid inside
Give 4 features of typical pneumonia presentation
Systemically unwell
Rapid onset
LOBAR consolidation on CXR
Responds to penicillins
Give 2 features atypical pneumonia presentation
Flu-like prodromes, often dry cough, myalgias
Respond to macrolides
What is the most common typical pneumonia? Give 3 features
Streptococcus pneumonia
Rusty coloured sputum
Gram +ve Diplococcus
+ve Urine antigen test
List 3 typical pneumonias
Streptococcus pneumoniae (aka pneumococcus)
Haemophilus influenzae B (Cavitating lesions)
Moraxella catarrhalis
In which patient group is haemophilia influenzae pneumonia more common? What type of organism is this?
COPD
Gram -ve coccobacillus
In which patient group is mortadella catarrhalis pneumonia more common? What type of organism is this?
Smokers
Gram -ve coccus
What is the treatment of a mild CAP?
Amoxicillin
What are the elements of CURB-65?
Confusion – AMTS < 9
Urea > 7mmol/L
Resp. rate > 30
BP < 90/60
65 or older
0-1: Treat at home- amoxicillin
2: Admit- co-amoxicillin + clarithromycin
3+: Admit, co-amoxicillin + clarithromycin, consider ITU
Give 4 causes of atypical pneumonia and their associated exposures
Mycoplasma pneumoniae: young people close proximity e.g. halls
Legionella pneumophila: A/C, plumbers, travellers
Chlamydia psittaci: Pet birds
Coxiella burnetti: Farm animals
Give 4 features of legionella pneumophila
Hepatitis
Hyponatraemia
Lymphopaenia
+ve urine antigen test
Give 2 signs of mycoplasma pneumoniae
Jaundice (cold AIHA)
Erythema multiform (Target shaped rash)
Give 4 symptoms of atypical pneumonias
Dry cough
Headache
Abdo pain
Diarrhoea
Which atypical pneumonias cause a culture -ve endocarditis?
Chlamydia psittaci
Coxiella burnetti
What investigations are required for atypical pneumonia?
- Sputum MCS
- Urine antigen
- Serology
- Blood film: mycoplasma- cold agglutins
What is the treatment for atypical pneumonia?
Clarithromycin
Give 3 common organisms causing HAP
Pseudomonas aeruginosa
Staphylococcus aureus (Cavitating lesions)
Klebsiella pneumoniae (ALCOHOLICS) (Cavitating lesions)
Give 3 features of S. aureus pneumonia
Often post- viral influenza
Cavitating lesions (abscess)
Grame +ve cocci in bunches
Give 4 features of Klebsiella pneumoniae
a/w Alcoholics + aspiration
Haemoptysis
Cavitating lesions
Gram -ve rods, anaerobic
What is the treatment of HAPs?
Ciprofloxacin + Vancomycin
Severe: Piperacillin/ tazobactam + Vancomycin
What is the treatment if confirmed MRSA pneumonia?
Vancomycin
What is the treatment if confirmed pseudomonas pneumonia?
Piperacillin/ tazobactam
Give 3 organisms that cause pneumonia in HIV patients
Pneumocystis jirovecii
TB
Cryptococcus neoformans
Splenectomy patients are more susceptible to which organisms causing pneumonia?
Encapsulated organisms
Neisseria
Haemophilus
Streptococcus
Cystic fibrosis patients are more susceptible to which organisms causing pneumonia?
Pseudomonas aeruginosa
Burkholderia cepacia
Infection with which organism is a contraindication for lung transplant in CF patients?
Burkholderia cepacia
Give 2 risk factors for aspergillum pneumonia
Immunocompromised (Neutropenia)
Asthma
What must be checked before starting monoclonal therapy?
TB status as can cause TB reactivation
What is the diagnosis? Describe what is seen
PCP
Honeycombing, big cystic spaces
What is the diagnosis? Describe what is seen
PCP
Batwing shadowing- ground glass shadowing
What is seen on CXR in aspergillus pneumonia?
Halo sign
What is the treatment for aspergillus pneumonia?
Amphotericin B
Give 2 symptoms of pneumocystis jirovecii pneumonia
Dry cough
SOBOE (insidious onset)
What is the treatment for pneumocystis jirovecii pneumonia
Co-trimoxazole
What antibiotics should be used for anaerobes causing pneumonia ?
Metronidazole
