First Aid, Chapter 7 Hypersensitivity Disorders, Hypersensitivity Pneumonitis

Question 1

What are the Immunologic Lung Disease broad categories? What diseases fit within each category?

Answer 1

TH1
CD8: HP and COPD
CD4: granulomatous - TB, sarcoid, and berylliosis

TH2
Asthma, ABPA, pulmonary eosinophilia, HIV, and Graves’ disease

Question 2

What are the 3 types of HP?

Answer 2

Acute, Subacute, Chronic

Question 3

What are the features of acute HP with regard to symptoms, onset, recovery, and CT findings?

Answer 3

• Explosive respiratory symptoms
• Takes 4–6 hours
• Nonproductive cough
• Fever present
• Recovery spontaneous
• On HRCT: Normal or fleeting ground glass opacities seen

Question 4

What are the features of subacute HP with regard to symptoms, onset, recovery, and CT findings?

Answer 4

• Progressive
• Slow onset
• Productive cough
• No systemic symptoms
• HRCT: Diffuse micronodules, air trapping, mild fibrosis

Question 5

What are the features of chronic HP with regard to symptoms, onset, recovery, and CT findings?

Answer 5

• No explosive symptoms
• No fever
• Fibrotic lung
• Anorexia
• Weight loss
• Permanent damage likely
• HRCT: Ground-glass opacities, emphysema, honeycombing, and parenchymal micronodules

Question 6

What is the antigen in Farmer’s lung? What is the source?

Answer 6

Antigen: Faenia rectivirgula or Micropolyspora faeni

Source: moldy hay and compost

Question 7

What is the source of the HP antigen Thermoactinomyces vulgaris?

Answer 7

Bagassosis (moldy sugar cane)

Question 8

What is the antigen in ventilation pneumonitis (humidifier/AC induced)?

Answer 8

Thermoactinomyces sacchari, Naegleria gruberi, or Acanthamoeba

Question 9

What is the antigen in humidifier’s lung (cool mist humidifier)?

Answer 9

Bacillus cereus or Klebsiella oxytoca

Question 10

What is the antigen in hot tub lung?

Answer 10

Mycobacterium avium intracellulare (MAI)

Question 11

What is the antigen in malt worker’s lung (malt, tobacco, and soy)?

Answer 11

Aspergillus species

Question 12

What is the antigen in cheese worker’s lung (moldy cheese?

Answer 12

Penicillium casei or P. roqueforti

Question 13

What is the antigen in machine operator’s lung?

Answer 13

Pseudomonas, Acinetobacter, or Mycobacter

Question 14

What is the antigen in bird fancier’s lung? What group has a good prognosis?

Answer 14

Avian proteins or Aspergillus species, kids have a good prognosis.

Question 15

What is the antigen in detergent worker’s lung?

Answer 15

Bacillus Subtilis

Question 16

What is the antigen in Woodworker’s lung?

Answer 16

Alternaria species

Question 17

What is the antigen in winegrower’s lung?

Answer 17

Stachybotrys

Question 18

What is the antigen in Air-conditioner lung?

Answer 18

Aureobasidium

Question 19

What is the antigen in summer-type lung (Japan)?

Answer 19

Trichosporum cutaneum

Question 20

What is the antigen in El NIno lung?

Answer 20

Pezizia

Question 21

What is the antigen in Saxophonist’s lung?

Answer 21

Candida albicans

Question 22

What is the antigen in basement shower lung?

Answer 22

Epicoccum nigricans

Question 23

What is the antigen in wheat weevil lung?

Answer 23

Sitophilus

Question 24

What is the antigen in paint finisher’s lung?

Answer 24

Toluene or toluene diisocyanate (TDI)

Question 25

What is the antigen in chemical worker's lung?

Answer 25

Diphenylmethane diisocyanate (MDI)

Question 26

What is the antigen in epoxy resin worker's lung?

Answer 26

Phthalic acid

Question 27

What is the antigen in plastic worker's lung?

Answer 27

Trimellitic anhydride

Question 28

What are the diagnostic criteria for HP?

Answer 28

-HP symptoms -Evidence of exposure (history and +IgG) + Radiograph of chest or high-resolution computed tomography (HRCT, reticular, nodular, or ground-glass opacities) -Bronchoalveolar lavage (BAL) lymphocytosis > 20% (low CD4:CD8 ratio

Question 29

What are the BAL findings in HP?

Answer 29

``` ↑CD8 (CD4:CD8 20% ↑ neutrophils ↑ eosinophils >1% of WBCs in BAL are mast cells ↑ IgG, IgA, IgM ↑ hyaluronic acid ```

Question 30

What are the lung biopsy findings in HP?

Answer 30

Noncaseating granulomas Mononuclear cell infiltrates of alveolar walls (lymphocytes, plasma cells) Foamy histiocytes in alveoli Giant cells peribronchiolar fibrosis

Question 31

What are the PFT findings in HP?

Answer 31

↓FEV1 after 4–6 hr of exposure ↓FVC after 4–6 hr of exposure ↓DLCO after 4–6 hr of exposure

Question 32

What are the lab differences in asymptomatic vs. symptomatic HP?

Answer 32

Asymptomatic CD4>CD8 Normal CD8 numbers Normal IgM Symptomatic CD8>CD4 Low CD8 High IgM

Question 33

What are drugs that can cause HP?

Answer 33

Mnemonic: A Boy Came From a Good Home to Make Nice Purple Sweets Amiodarone Beta Blockers Chlorambucil, clozapine, cyclosporine Fluoxetine Gold Heroin, HMG Co-A reductase inhibitors Methotrexate, minocycline Nitrofurantoin Procarbazine Sulfasalazine

Question 34

What is Organic dust toxic syndrome (ODTS, pulmonary mycotoxicosis)

Answer 34

Noninfectious, febrile illness that occurs in workers after exposure to dust contaminated by bacterial and/or fungal spores (from inhalation of toxinproducing fungi-contaminated aerosols [i.e., grain, hay]) 30 to 50 times more common than HP; young patients; usually contracted in the summer months; complete recovery.

Question 35

What is fire-eater's lung?

Answer 35

Choking, coughing, respiratory symptoms from aspiration of the flammable petrochemicals used during the fire-eating demonstration. Fever and pleuritic chest pain also seen

Question 36

What is humidifier fever?

Answer 36

Toxic alveolitis, recirculated water with endotoxin, chest tightness occurs 4–8 hours after exposure; resolves in hours

Question 37

What is silo unloaders disease?

Answer 37

Acute exposure to NO2, leading to asphyxia (i.e., a farmer entering a silo)

Question 38

What is byssinosis?

Answer 38

Dust inhalation of cotton, flax, and hemp; bronchoconstriction first day of exposure; tends to improve as the week goes on

Question 39

In what percent of histiocytosis patients does pneumothorax occur?

Answer 39

10%

Question 40

What cell is predominant in usual interstitial pneumonia (UIP)? What physical exam finding is typical?

Answer 40

Clubbing present and neutrophil predominant

Question 41

What is occasional interstitial lung disease (ILD)?

Answer 41

Secondary to flock or nylon; lifeguarding at the pool, with endotoxin as the culprit

Question 42

What is the most common type of HP?

Answer 42

Farmer's lung

Question 43

What is more common than farmer's lung in farmers? How can you distinguish the two?

Answer 43

ODTS Organic dust toxic syndrome (nonimmunologic) up to 50 times more common. Farmer’s lung occurs after prolonged exposure, whereas ODTS occurs after a single highdose exposure.

Question 44

What is the most common pathogen seen in contamination of water and ventilation systems?

Answer 44

MAI

Question 45

Is smoking pathologic in HP? Why?

Answer 45

No, it is protective due to decreased antibody response to antigen in the lung.

Question 46

What is the particle size of agents in HP?

Answer 46

Must be

Question 47

What is the timing of the cells that are involved in HP?

Answer 47

Eosinophils and PMNs after a few hours, lymphocytes infiltrate after a few days and macrophages over months

Question 48

What is the treatment of HP?

Answer 48

Avoidance of offending agent. Glucocorticoids in severe or persistent symptoms accelerate recovery. Use daily for 1–2 weeks and taper over next 2–4 week