Pulmonary infection

Question 1

Young lady with BM transplant presents with cough, skin abscess and listlessness. Sputum shows gram +ve bacteria. What is the cause?

Actinomyces israelii
Bacillius anthracis
Nocardia
PCP
TB

Answer 1

Nocardia
- cause triad of pneumonia, CNS involvement and skin abscess
- post-tx immunocompromised
- gram +ve, acid-fast
–>treat with septrin, amikacin or 3rd gen cephalosporin for 6-12months

Actino
- head and neck skin changes
- after dentist work or intrauterine contraceptive implant
- more indolent infection
- immunocompromised /COPD/poor oral hygiene
- gram +ve, yellow sulphur granules
–> treat penicillin

Bacillus
- flu-like symptoms
- skin abscess black

Question 2

What big causes a pleural effusion with an alkaline pH?

Answer 2

Proteus mirabilis (due to ammonia production)

Question 3

How is severity of PCP classified?

Answer 3

Mild = paO2>9.3
Mod/Sev = paO2≤9.3

Difference is that give oral steroids in mod/sev

Question 4

What is the infectious profile of pt with well-controlled HIV?

Answer 4

Increased risk of pneumonia, TB, COPD, pulmonary HTN and lung cancer even if normal CD4 count
Increased risk of cavitation and empyema

Question 5

What might you expect to see in immunoglobulin profile of pt on longterm steroids?

Answer 5

Isolate IgG deficiency

Question 6

What might you expect on bloods in CVID?

Answer 6

IgG deficiency + IgA or M
Poor vaccine response

Nb. need age>4

Question 7

What immunodefiency should you suspect if normal immunoglobulin levels?

Answer 7

Specific Ab deficiency

Question 8

What kind of lung disease do you see with CVID/XLA?

Answer 8

Bronchiectasis
Asthma
ILD (resembling sarcoid)
Atypical lymphoid infiltrates (multiple nodules that may resolve spontaneously)

Nb. also get sinus infections
Nb. most common bacteria = encapsulated: pneumococcus and haemophilus
Nb. Get lots of viral infections

Question 9

What kind of infections to pt with CVID tend to get?

Answer 9

Sinus
Viral
Encapsulated bacteria: pneumococcus and haemophilus

Question 10

When might you suspect specific Ab deficincy vs CVID?

Answer 10

Also get sino-pulmonary/ear infections but less severe
Will have normal Ig levels and response to protein-based vaccines

Nb. treat with higher dose and prolonged abx. Occasionally need prophylaxis.

Question 11

When might you suspect XLA?

Answer 11

<5yrs, male relative with disease
Recurrent pyogenic ifx (s.pneum, h.inf, s.aureus, pseud)

Nb. BTK gene mutation
Nb2. manage like bronchiectasis and IgG therapy

Question 12

When might you suspect Good’s syndrome?

Answer 12

Looks a bit like CVID/XLA but late onset and have hx of thymectomy

Question 13

What is hyper igE syndrome?

Answer 13

Immune deficiency - get high IgE and eosinophila
Get eczema and fungal infections and structural pulmonary and vascular dsiease

Question 14

Does selective IgA deficiency tend to cause infections?

Answer 14

No

Question 15

What infection should you be suspiciou of if been to farm?

Answer 15

Coxiella burnetti

Question 16

Why might you suspect Mycoplasma pneumonia?

Answer 16

Lethargy, fevers, non-productive cough, headache
Widespread rash, sore throat/hoarse voice

Often young adult, smoker

CXR: peribronchial and perivascular reticular interstitial infiltrates

Tx: macrolide or tetracycline

Nb. won’t show up on gram stain

Question 17

What is Loeffler’s syndrome?

(don’t confuse with Lofgrens = sarcoid: fever, erythema nodosum + bihilar infiltrates)

Answer 17

Benign pulmonary eosinophilia
- pulmonary infiltrates
- peripheral eosinophilia
- cough, sob, wheeze
- secondary allergic response to helminth: ascaris, strongyloides

Question 18

Differential between:
1) Blastomycosis
2) Coccidiomycosis
3) Histoplasmosis
4) Mucormycosis
5) Paracoccidiomycosis

Answer 18

1) outdoor activities near water
cough/SOB/skin or bone lesions
lobar consolidation, diffuse or nodular infiltrates

2) desert, sand storms, construction, military exercise
cough/SOB/fever/fatigue
eosinophilia, lobar consolidation, focal or diffuse infiltrates, cavities, effusion

3) America (ohio river), bat/rodent droppings (often in soil)
cough/SOB/fever/arthalgia
focal, diffuse or cavitatory infiltrates, lymphadenopathy

4) Immunocompromised
Fever/cough/chest pain/SOB
Solitary nodule/lobar consolidation/cavitatory lesion or disseminated forms

5) South America
Acute: Fever/wt loss/hepatosplenomegaly/lymphadenopathy
Chronic: cough/SOB/haemoptysis/wt loss
Diffuse/nodular infiltrates

Question 19

What classifies someone as having severe covid?

Answer 19

One of:
- RR >30
- severe resp distress
- SATS <90%

Question 20

When should CPAP be offered in COVID?

Answer 20

Needing 40% oxygen or more

Nb. Target sats >=94%

Question 21

What are indications for Tociluzumab?

Answer 21

CRP>75 when commenced on CPAP

Question 22

What are indications for Remdesevir?

Answer 22

Low flow oxygen NOT HFNO, CPAP, invasive

Question 23

What are indications for Nirmatrelvir/Ritonavir? (Paxlovid)

Answer 23

Not on oxygen
High risk of progression to severe COVID

Question 24

When can oseltamivir be used?

Answer 24

Influenza and known influenza A or B circulating
<48hrs symptom onset
High risk patient - includes diabetes, chronic resp/heart/liver/renal/neuro - nb includes asthma

Question 25

Farmer presents with 24hr hx of fever, myalgia, cough and large volume haemoptysis. He has jaundice and conjunctival haemorrhages. He has coagulopathy, thrombocytopaenia, acute renal and liver dysfunction. Autoimmune screen negative. What is most likely diagnosis?

Answer 25

Leptospira (Weil’s disease)