242.1 🎓 醫孞生版

242.1.0.1 📌 䞀頁重點

242.1.0.1.1 Candida Species
  • C. albicans — most common; mostly antifungal-sensitive
  • C. glabrata — fluconazole-resistant often (esp. higher doses or alternative needed)
  • C. parapsilosis — neonatal + line; some echinocandin variable
  • C. tropicalis — neutropenic invasive
  • C. krusei — intrinsic fluconazole resistance
  • C. auris — multi-drug resistant; nosocomial outbreaks (Ch 252)
  • C. dubliniensis — HIV oral candidiasis (mimics albicans)
242.1.0.1.2 Clinical Forms
242.1.0.1.2.1 Mucocutaneous
  • Oropharyngeal Candidiasis (“Thrush”): white pseudomembranous plaques on tongue/buccal mucosa; HIV CD4 < 200, dentures, inhaled steroids, post-antibiotic, diabetes, infants
  • Esophageal Candidiasis: dysphagia + odynophagia; HIV CD4 < 100; AIDS-defining
  • Vulvovaginal Candidiasis (VVC): pruritus + discharge (“cottage cheese”) + dyspareunia; pregnancy, OCs, antibiotics, DM
  • Cutaneous Candidiasis: intertriginous (moist areas — skin folds, diaper area); satellite lesions
  • Chronic Mucocutaneous Candidiasis (CMC): rare immune defect; persistent
242.1.0.1.2.2 Invasive Candidiasis
  • Candidemia: bloodstream; ICU + line + neutropenia + abdominal surgery + DM + parenteral nutrition
  • Intra-Abdominal: peritonitis, abscess; post-surgery + perforation + necrotizing pancreatitis
  • Disseminated: skin lesions, ocular (chorioretinitis), hepatic + splenic (chronic disseminated post-leukemia chemo)
  • Endocarditis: prosthetic valve + IVDU
  • Meningitis: rare, neonatal + shunt + steroids
  • UTI: catheter-related + obstruction
  • Osteomyelitis + septic arthritis
242.1.0.1.3 Risk Factors for Invasive Candidiasis
  • ICU stay > 5 days
  • Central venous catheter
  • Broad-spectrum antibiotics
  • Parenteral nutrition
  • Abdominal surgery (especially with perforation)
  • Neutropenia (chemotherapy, transplant)
  • Hemodialysis
  • Diabetes mellitus
  • Severe burns
  • Pre-existing colonization at multiple body sites
242.1.0.1.4 Diagnosis
  • Mucocutaneous: clinical (oral thrush, vaginal discharge with KOH wet mount)
  • Invasive: blood cultures (50%+ sensitivity in candidemia), tissue biopsy + cultures
  • β-D-glucan: serum marker — elevated in invasive candidiasis (and PJP, Aspergillus); not specific
  • T2 Magnetic Resonance (Candida T2MR): rapid culture-independent diagnosis (FDA 2014)
  • PCR: emerging
  • Ophthalmologic exam: all candidemia patients (chorioretinitis risk — IDSA recommendation)
242.1.0.1.5 Treatment
242.1.0.1.5.1 Mucocutaneous
  • Oropharyngeal: clotrimazole troches, nystatin swish-and-swallow, fluconazole 100-200 mg × 7-14 d
  • Esophageal: fluconazole 200-400 mg × 14-21 d; echinocandin or AmB if refractory / severe
  • VVC: fluconazole 150 mg PO × 1 (or topical azoles); recurrent (≥ 4/yr) — fluconazole weekly suppression
  • Severe / recurrent / non-albicans: ibrexafungerp (oral, FDA 2021) alternative
242.1.0.1.5.2 Invasive
  • Echinocandin first-line (caspofungin, micafungin, anidulafungin, rezafungin)
  • Step-down to fluconazole if azole-sensitive species (after stable + neg cultures + species ID)
  • Voriconazole if C. krusei or specific scenarios
  • AmB if severe / endocarditis / specific indications
  • Duration: 14 days after first negative blood culture (candidemia) + clinical improvement
  • Source control: line removal, debridement, surgery
242.1.0.1.6 Special
  • C. krusei: echinocandin (intrinsic fluconazole R)
  • C. auris: echinocandin (but resistance growing; AST + ID consult)
  • C. glabrata: echinocandin preferred; fluconazole if high-dose + sensitive
  • C. parapsilosis: fluconazole or echinocandin (some echinocandin resistance)
242.1.0.1.7 IDSA Recommendations
  • Ophthalmologic exam within 1 week of candidemia diagnosis (chorioretinitis 9-37%)
  • Repeat blood cultures until clear
  • Line removal if catheter-related
  • TEE for persistent candidemia + endocarditis suspicion

242.1.0.2 1⃣ Candida Species + Pathogenesis

242.1.0.2.1 Candida albicans
  • Most common Candida species in humans
  • Commensal of GI + GU + skin
  • Dimorphic (yeast + hyphal forms — virulence factor)
  • Becomes pathogenic with immune compromise, mucosal disruption, antibiotic flora changes
242.1.0.2.2 Other Common Species
242.1.0.2.2.1 C. glabrata
  • Small yeast, no pseudohyphae
  • High fluconazole resistance (often need higher dose or echinocandin)
  • Common in immunocompromise + elderly + diabetic
  • Some echinocandin resistance emerging (FKS gene mutations)
242.1.0.2.2.2 C. parapsilosis
  • Common in neonatal + ICU + line infections
  • Variable echinocandin susceptibility — sometimes higher MIC
  • Pediatric concern
  • Adheres to plastic surfaces (catheters)
242.1.0.2.2.3 C. tropicalis
  • Common in neutropenic + leukemia
  • Often invasive + disseminated
242.1.0.2.2.4 C. krusei
  • Intrinsic fluconazole resistance (do not use fluconazole)
  • Voriconazole or echinocandin
  • Important consideration in azole-prophylaxis breakthrough
242.1.0.2.2.5 C. auris (Ch 252)
  • WHO critical priority pathogen
  • Often multi-drug resistant (fluconazole + amphotericin + echinocandin variable)
  • Nosocomial outbreaks
  • 2024 + ongoing increasing cases globally
242.1.0.2.2.6 C. dubliniensis
  • Mimics C. albicans; HIV oral candidiasis common cause
  • Fluconazole-sensitive often

242.1.0.3 2⃣ Pathogenesis + Risk Factors

242.1.0.3.1 Mucocutaneous
  • Disruption of mucosal barrier
  • Immunosuppression (HIV, steroids, immunocompromise)
  • Antibiotic use (flora alteration)
  • Diabetes mellitus
  • Inhaled corticosteroids (oral thrush)
  • Pregnancy + OCs (VVC)
  • Dentures, smoking, hyposalivation
242.1.0.3.2 Invasive
  • Central venous catheter (especially long-term TPN)
  • Broad-spectrum antibiotics (alters flora)
  • ICU stay prolonged
  • Parenteral nutrition
  • Abdominal surgery + GI perforation
  • Neutropenia (chemotherapy, transplant, leukemia)
  • Hemodialysis
  • Severe burns
  • Pre-existing colonization at multiple body sites (multifocal colonization predicts invasive)
  • Diabetes mellitus (severe)
  • IDU (endocarditis)

242.1.0.4 3⃣ Mucocutaneous Candidiasis

242.1.0.4.1 Oropharyngeal Candidiasis (“Thrush”)
242.1.0.4.1.1 Forms
  • Pseudomembranous: white plaques on tongue + buccal mucosa (classic; “cottage cheese on mucosa”)
  • Erythematous (atrophic): red painful patches on palate / dorsum tongue (denture wearers, smoking)
  • Hyperplastic (leukoplakia): chronic; difficult to scrape off; sometimes precancerous
242.1.0.4.1.2 Risk
  • HIV CD4 < 200 (AIDS-defining at < 200)
  • Inhaled corticosteroids (e.g., asthma inhalers)
  • Dentures + denture stomatitis
  • Diabetes
  • Post-antibiotic
  • Chemotherapy / immunocompromise
  • Hyposalivation (Sjögren’s, radiation)
  • Infants (transient, normal)
  • Older adults (decreased immunity)
242.1.0.4.1.3 Diagnosis
  • Clinical (visible plaques)
  • KOH preparation: budding yeast + pseudohyphae
  • Culture rarely needed (clinical Dx)
242.1.0.4.1.4 Treatment
  • Mild:
    • Clotrimazole troches 10 mg 5×/d × 7-14 d
    • Nystatin swish-and-swallow 100,000 U/mL × 5 mL qid × 7-14 d
    • Miconazole buccal tablet
  • Moderate:
    • Fluconazole 100-200 mg PO × 7-14 d
  • Refractory / Severe:
    • Fluconazole 200-400 mg
    • Itraconazole solution
    • Posaconazole
    • IV echinocandin
    • Amphotericin B oral suspension (rare)
  • HIV: initiate / optimize ART (immune recovery)
242.1.0.4.2 Esophageal Candidiasis
242.1.0.4.2.1 Risk
  • HIV CD4 < 100 (AIDS-defining)
  • Immunocompromise
  • Sometimes inhaled steroids (mild)
242.1.0.4.2.2 Clinical
  • Odynophagia (painful swallowing)
  • Dysphagia
  • Retrosternal pain
  • Often concurrent oral thrush
  • Esophageal ulceration
242.1.0.4.2.3 Diagnosis
  • Clinical (especially HIV+ with oral thrush + odynophagia — empirical Tx)
  • EGD if refractory or unclear (white plaques, ulcers, biopsy + culture)
  • Differential: HSV (small punched-out ulcers), CMV (large linear ulcers), pill esophagitis, reflux
242.1.0.4.2.4 Treatment
  • Fluconazole 200-400 mg PO daily × 14-21 days (empirical for HIV with thrush)
  • Echinocandin or AmB IV if refractory / severe / not tolerating PO
  • Posaconazole alternative
  • HIV: ART critical
242.1.0.4.3 Vulvovaginal Candidiasis (VVC)
242.1.0.4.3.1 Common Causes
  • C. albicans (90%)
  • C. glabrata (10% — often fluconazole-resistant)
242.1.0.4.3.2 Risk
  • Pregnancy
  • Oral contraceptives
  • Diabetes mellitus (especially uncontrolled)
  • Post-antibiotic
  • Tight clothing + synthetic underwear
  • Vaginal douching
  • HIV / immunocompromise
242.1.0.4.3.3 Clinical
  • Pruritus (intense)
  • Burning + dyspareunia
  • White “cottage cheese” discharge
  • Vulvar erythema + edema
  • Satellite lesions in surrounding skin
242.1.0.4.3.4 Diagnosis
  • Wet mount with KOH: budding yeast + pseudohyphae
  • Vaginal pH 4-4.5 (normal); pH > 4.5 suggests trichomoniasis or BV
  • Culture if recurrent / atypical / fluconazole-resistance suspected
242.1.0.4.3.5 Treatment
242.1.0.4.3.6 Uncomplicated
  • Fluconazole 150 mg PO × 1 dose
  • Topical azoles (clotrimazole, miconazole, tioconazole) × 1-7 days
  • Ibrexafungerp 300 mg PO × 2 doses (Brexafemme, FDA 2021)
  • Equivalent efficacy
242.1.0.4.3.7 Complicated (Severe, Pregnant, Recurrent, Non-Albicans)
  • Pregnant: topical azole (preferred over fluconazole, especially 1st trimester)
  • Severe: fluconazole 150 mg PO q72h × 3 doses
  • Recurrent (≥ 4 episodes/yr):
    • Acute: 3 doses of fluconazole
    • Maintenance: fluconazole 150 mg PO weekly × 6 months
    • Ibrexafungerp approved for recurrent VVC (Brexafemme)
  • Non-albicans (C. glabrata, C. krusei): topical boric acid 600 mg capsule daily × 14 days; ibrexafungerp
242.1.0.4.3.8 Pregnancy
  • Topical azoles 7-day course preferred (clotrimazole, miconazole)
  • Avoid fluconazole high-dose (teratogenic 1st trimester)
  • Single 150 mg fluconazole low-risk in some studies
242.1.0.4.4 Cutaneous Candidiasis
242.1.0.4.4.1 Forms
  • Intertrigo: moist skin folds (axilla, groin, beneath breasts, abdominal folds in obesity)
  • Diaper rash (pediatric)
  • Candidal paronychia: chronic finger immersion in water
  • Candidal balanitis: penile / glans
242.1.0.4.4.2 Treatment
  • Topical azoles (clotrimazole, miconazole) or nystatin
  • Keep area dry
  • Oral fluconazole if severe / extensive
  • Underlying cause (DM, immune status)
242.1.0.4.5 Chronic Mucocutaneous Candidiasis (CMC)
242.1.0.4.5.1 Background
  • Rare immune defect (often autoimmune polyendocrinopathy syndrome type 1 — APS-1 / APECED)
  • AIRE gene mutations
  • T cell dysfunction
  • Persistent / recurrent mucocutaneous Candida infections
242.1.0.4.5.2 Clinical
  • Persistent oral thrush
  • Cutaneous candidiasis (often disfiguring)
  • Onychomycosis
  • Associated endocrinopathies (hypoparathyroidism, adrenal insufficiency)
  • Autoimmune phenomena
242.1.0.4.5.3 Treatment
  • Long-term azole (fluconazole, itraconazole)
  • Immunomodulators
  • Address autoimmune conditions

242.1.0.5 4⃣ Invasive Candidiasis

242.1.0.5.1 Candidemia
242.1.0.5.1.1 Background
  • Bloodstream infection with Candida species
  • Major nosocomial infection (4th most common bloodstream pathogen in USA)
  • Mortality 40-60% in severe / late diagnosis
242.1.0.5.1.2 Risk
  • Central venous catheter
  • Broad-spectrum antibiotics
  • Parenteral nutrition
  • Abdominal surgery
  • ICU stay > 5 days
  • Neutropenia
  • Hemodialysis
  • DM
  • Severe burns
  • Multifocal colonization
242.1.0.5.1.3 Clinical
  • Fever (often only sign)
  • Sepsis-like
  • Multi-organ involvement in severe (kidney, brain, eyes, skin, heart)
  • Endophthalmitis / chorioretinitis (9-37%)
  • Skin lesions (small papules)
242.1.0.5.1.4 Diagnosis
  • Blood cultures (sensitivity 50%+; multiple sets, growth often within 1-3 days)
  • β-D-glucan elevated (also PJP + Aspergillus)
  • T2 Candida MR (FDA 2014): rapid (1-2 hr); culture-independent
  • PCR of blood (emerging)
  • Speciation + AST important
242.1.0.5.1.5 Ophthalmology Recommendation
  • All candidemia patients → ophthalmologic exam within 1 week
  • Chorioretinitis 9-37% (especially with prolonged candidemia)
  • Endophthalmitis sight-threatening
  • Intravitreal antifungal if active retinal disease
242.1.0.5.1.6 Treatment
242.1.0.5.1.7 First-Line
  • Echinocandin (caspofungin 70 mg load → 50 mg/d; micafungin 100 mg/d; anidulafungin 200 mg load → 100 mg/d; rezafungin 400 mg load → 200 mg/wk)
  • Empirical broader Tx in immunocompromise with mold risk (voriconazole / isavuconazole / liposomal AmB)
242.1.0.5.1.8 Step-Down
  • After 5-7 days + clinical improvement + neg cultures + species + AST
  • Fluconazole 400 mg/d if azole-sensitive species
242.1.0.5.1.9 Duration
  • 14 days after first negative blood culture + clinical resolution (for uncomplicated candidemia)
  • Longer for deep-seated infections + endocarditis + endophthalmitis
242.1.0.5.1.10 Source Control
  • Central line removal (essential — biofilm)
  • Debridement
  • Surgery for intra-abdominal source
242.1.0.5.1.11 Salvage
  • AmB liposomal
  • Combination therapy
242.1.0.5.2 Intra-Abdominal Candidiasis
242.1.0.5.2.1 Risk
  • Abdominal surgery
  • GI perforation
  • Pancreatitis (necrotizing)
  • Intra-abdominal abscess
  • Prolonged hospitalization
242.1.0.5.2.2 Clinical
  • Often subacute
  • Fever, abdominal pain
  • Sometimes only fever in ICU patient
242.1.0.5.2.3 Treatment
  • Echinocandin
  • Source control (drainage, surgery)
  • 14+ days
242.1.0.5.3 Disseminated Candidiasis
242.1.0.5.3.1 Skin
  • Small erythematous papules (small “spots” 5-10 mm)
  • Painful sometimes
242.1.0.5.3.2 Hepatosplenic (Chronic Disseminated)
  • Post-leukemia chemotherapy
  • Multifocal liver + spleen lesions on US/CT
  • Difficult to treat
  • Long course required (months)
  • Echinocandin + azole combination sometimes
242.1.0.5.3.3 Endophthalmitis / Chorioretinitis
  • 9-37% of candidemia
  • White retinal lesions
  • Vitritis + visual decline
  • Intravitreal voriconazole or AmB + systemic antifungal
242.1.0.5.3.4 CNS
  • Rare
  • Neonatal / shunt / steroids
  • Lipid-formulation AmB ± flucytosine (penetrates CSF)
  • Voriconazole alternative
242.1.0.5.4 Endocarditis
242.1.0.5.4.1 Risk
  • Prosthetic valve
  • IVDU
  • Persistent candidemia
242.1.0.5.4.2 Treatment
  • Liposomal AmB or echinocandin + flucytosine
  • Surgical valve replacement often required
  • 6+ weeks IV + chronic suppression with fluconazole
242.1.0.5.5 UTI
242.1.0.5.5.1 Background
  • Catheter-related primarily
  • Asymptomatic candiduria common (don’t always treat)
  • Symptomatic cystitis + complicated (obstruction, neutropenia, instrumentation): treat
242.1.0.5.5.2 Treatment
  • Fluconazole preferred (penetrates urine well)
  • AmB bladder irrigation rarely used
  • Echinocandin NOT preferred (poor urinary concentration)
  • Catheter change
242.1.0.5.6 Osteomyelitis + Septic Arthritis
  • Rare
  • Echinocandin × 6-12 months + surgical debridement

242.1.0.6 5⃣ Special Considerations

242.1.0.6.1 C. auris (See Ch 252)
  • WHO critical priority pathogen
  • Multi-drug resistant
  • Nosocomial outbreaks
  • Echinocandin first-line (but some R)
  • 2024+ ongoing global increase
  • Infection control critical
242.1.0.6.2 Neonatal Candidiasis
  • Premature infants major risk
  • C. parapsilosis common
  • Echinocandin or fluconazole
  • Source control + line removal
242.1.0.6.3 Pediatric Candidiasis
  • Same principles as adult; weight-based dosing
242.1.0.6.4 Pregnancy
  • VVC: topical azoles preferred
  • Invasive: liposomal AmB or echinocandin
  • Avoid high-dose fluconazole 1st trimester
  • Voriconazole avoided (teratogenic concern)