Parasites Flashcards
Normal IgE and eosinophil values?
- 0-180 IU/mL
- 1-7%
Malignancy associated with eosinophilia?
15% of Hodgkins lymphoma
Autoimmune vasculitis associated with eosinophilia?
- Churg-Strauss syndrome - allergic granulomatous angiitis (medium and small arteries and veins)
- c-ANCA along with Wegener’s and microscopic polyangiitis
What is unique about the presentation of Churg-Strauss?
- SEQUENTIAL
- allergic rhinitis –> asthma –> vasculitis
- multisystem involving paranasal sinuses, lungs, nerves, skin, joints (Wegener’s hits upper respiratory tract, lungs, kidneys)
Which fungal infection is associated with eosinophilia?
Coccidiomycosis (desert southwest)
Remember, cholesterol emboli can produce eosinophilia
RARE
What fungal infection can mimic TB in almost every way?
Histoplasmosis
What three organisms can produce CXR miliary pattern?
- histo, blasto, TB
What two parasites can participate in person-person transmission?
- strongyloides
- amoeba
What is the commonest helminth infection?
ascaris lumbricoides
Transmission and life cycle of ascaris?
- fecal-oral ingestion of eggs
- lungs - coughed and swallowed - maturation in GIT
What is Loeffler’s syndrome? Associated organism?
- initial migration of ascaris larvae through luna may produce TRANSIENT pulmonary symptoms (cough), radiographic opacities, and eosinophilia
- adult eventually croaks and infection ends
How is hookworm route of transmission different from ascaris?
- dermal penetration
- fecal-oral ingestion
Which helminth survives chronically due to auto-infection? Transmission?
Strongyloides stercoralis - eggs hatch and re-infect GI tract
DERMAL penetration
What is a complication of strongyloides in immunocompromised?
- hyperinfection - larvae migrate throughout boy with disastrous results
- larvae take bowel bacteria out with them = polymicrobial sepsis
What parasite is prevalent in areas with livestock and canines? Transmission?
Echinococcus - egg ingestion
Which parasite produces mass lesions (cysts)?
Echinococcus
Which parasite commonly causes hemoptysis and sets up shop via cysts in the lungs (instead of the bowel)? Transmission?
- Paragonimus westermani
- requires right kind of snail and crustacean = ingestion or raw/undercooked shellfish
Presentation of paragonimiasis?
- adult organisms encyst in lungs producing pneumonic infiltrates, cavities, and pleural effusions
- hemoptysis – can mimic TB
How does lymphatic filariasis occur?
- mosquito carries parasite and bites human
- adults live in inguinal LN’s/vessels
- microfilaria (larvae) migrate through lymph at night and mosquito bites you, passing on the infection
What is a common symptom of lymphatic filariasis?
- large adult parasite burdens may obstruct lymphatic vessels causing elephantiasis of genitals and LE’s
70% of infections by what organism occur in Nigeria, Bangladesh, and Indonesia?
Wucheria –> lymphatic filariasis
What is the hypersensitivity response to migrating microfilariae called?
Tropical pulmonary eosinophilia - 0.5% of infected patients (South Asians)
Pathogenesis of TPE?
- microflariae are opsonized by AB’s and cleared by pulmonary microvasculature
Similarities and differences of TPE to asthma?
- wheezing, cough, dyspnea, worse at night (migration)
- variable age of onset, fever, malaise, weight loss and persistent profound blood eosinophilia (80,000)
- additionally, requires months in endemic area
What is seen in CXR of TPE patients?
- reticulonodular or military opacities in mid/lower lung zones
- 20% may have normal CXR
What are complications of untreated TPE? Treatment?
- pulmonary HTN with granulomatous vasculitis becoming fibrosis with time
- diethylcarbamazine for 21 days
What is a paradoxical result seen in TPE?
- LACK of microfilariae in blood due to rapid immune clearance
