fungal infections

Question 1

Candidiasis

Answer 1

Most common fungal infection (candida albicans)

risk factors: immunocompromised

Can be:
Oral
vulvovaginal
invasive

Types:
Oral thrush (baby with white spots on throat)

Acute atrophic candidiasis

Angular cheilitis

Question 2

Candidiasis: pathogensis

Answer 2

Candida albicans: part of normal flora

Opportunistic in immunocompromised or when normal flora is disrupted

Oral Candida adheres to host surfaces

Candida growth must be at least in equilibrium with rate of oral epithelial replacement to become infectious

Question 3

Candidiasis: S&S

Answer 3

Thrush:
Oral discomfort
whitish plaques on tongue or oral mucosa

Question 4

Oral candidiasis

Answer 4

Acute atrophic candidiasis

Angular cheilitis (corners of mouth)

Question 5

Oral candidiasis: making the diagnosis

Answer 5

Oral swab, scraping, or rinse for potassium hydroxide (KOH) or methylene blue smear

-presence of budding yeast or pseudohyphae diagnostic

-pseudohyphae typically slender and septate

Fungal culture with susceptibility testing

Question 6

Oral Candidiasis: Treatment

Answer 6

First-line topical agents:
Clotrimazole trouches
Miconazole buccal tablets

Systemic therapy
Fluconazole

(-azole)!!

Question 7

Vulvovaginal candidiasis

Answer 7

Candida albicans accounts for 85-90% of vaginal yeast strains

Question 8

Vulvovaginal candidiasis: S&S

Answer 8

Thick white vaginal discharge (more cottage cheese like compared to STIs)

Vulvar pruritis and irritation

External dysuria and/or dyspareunia

Question 9

Vulvovaginal candidiasis: Diagnosis

Answer 9

Symptomatic women:

Wet prep (KOH) or gram stain of vaginal discharge

Yeasts, hyphae, or pseudohyphae

Culture or other test such as PCR or DNA probe

Needs to be distinguished from other causes of vaginitis

Question 10

Vulvovaginal Candidiasis: Treatment

Answer 10

Do not treat if asymptomatic

Topical agents:
Azole class(!!)

Oral agents:
Fluconazole as a single dose

Question 11

Vulvovaginal Candidiasis: Prognosis

Answer 11

50% of infected women have a second infection

5-10% of women will develop recurrent vulvovaginal candidiasis (≥ 3-4 episodes per year)

Question 12

Invasive Candidiasis

Answer 12

Bloodstream infection with Candida

Associated with complications: endophthalmitis, endocarditis, septic thrombophlebitis, renal candidiasis, hepatosplenic candidiasis, and meningitis

Question 13

Invasive Candidiasis: Risk Factors

Answer 13

colonization withCandidaat any site

presence of an indwelling catheter

hospital admission (particularly in the intensive care unit)

receipt of broad-spectrum antibiotics or parenteral nutrition (disrupts the delicate balance between good and bad bacteria)

immunocompromise, particularly neutropenia

corticosteroid use

Question 14

Invasive Candidiasis: Diagnosis & Management

Answer 14

Diagnosis:
-Blood culture or culture from other suspected site of involvement

Management:
-Start treatment before receiving culture results
-A delay in therapy is associated with increased mortality
-Echinocandin
-Growing Azole resistance

Question 15

Cryptococcosis

Answer 15

Enters the body through respiratory route

Can cause no infection, latent infection, or symptomatic disease:

Worldwide distribution in soil, decaying wood, tree hollows, bird droppings

Risk factors: immunocompromised, especially advanced HIV/AIDS

Question 16

Cryptococcosis: Symptoms

Answer 16

Asymptomatic

Latent

Symptomatic disease:
-Pneumonia: cough, fever, chest pain, weight loss
-Can disseminate to central nervous system (CNS) and cause meningoencephalitis
-Fever, headache, lethargy, mental status changes

Question 17

Cryptococcosis: Diagnosis

Answer 17

Culture
Microscopy
Antigen detection

Question 18

Cryptococcosis: Treatment

Answer 18

Flucon(azole): asymptomatic or mild to moderate infections

Severe pulmonary or CNS infections: amphotericin B plus flucytosine

Question 19

Histoplasmosis

Answer 19

Mycotic disease that primarily affects the lungs

Endemic in US: Mississippi and Ohio Valleys(!!)

Endemic in Mexico, Central and South America, parts of southern Europe, southeast Asia, and Africa

(lots of clues)

Question 20

Histoplasmosis: pathogenesis

Answer 20

Histoplasma capsulatum lives in soil contaminated bat droppings or bird feces

Spores are aerosolized and dispersed

Spores are inhaled into lower airways

Immunocompetent patients: >99% asymptomatic (may include systemic, respiratory, GI, neuro)

Question 21

Histoplasmosis: making diagnosis

Answer 21

Culture is gold standard but can take up to 6 weeks

Management: Asymptomatic do not require treatment

Acute pulmonary histoplasmosis: mild cases do not require treatment
-Itraconazole if symptoms last >1 month

Question 22

Histoplasmosis: Prevention

Answer 22

In endemic areas, demolition workers should wear respirators

In patients who are HIV positive:
-Primary prophylaxis with itraconazole if in a high-risk occupation or area

Question 23

Pneumocystis

Answer 23

Causes Pneumocystis pneumonia (PCP)

Opportunistic infection of the lungs caused by Pneumocystis jirovecii

One of the most common opportunistic infections in patients with HIV (PEARL, HIV patient having an opportunistic infection!!)

Question 24

Pneumocystis: symptoms

Answer 24

In patients with HIV:
progressive dyspnea on exertion
nonproductive cough
fever
chest discomfort
subacute onset (drawn out)

Question 25

Pneumocystis: Diagnosis

Answer 25

Chest x-ray:
CT scan if chest x-ray is nonspecific

(equal opportunist means it is on both sides of lungs in scan)

Sputum visualization of cysts on stained respiratory specimen

Question 26

Pneumocystis: Management

Answer 26

Begin empiric therapy immediately when PCP is suspected

Trimethoprim/sulfamethoxazole

Corticosteroids