Fungal Infections - Block 3 Flashcards
Ex of dermatophytes?
- Trichophyton
- Microsporum
- Epidermophyton
Types of Yeast?
- Candida
- Cryptococcus neoformans
Types of mold?
Aspergillus
Types of dimorphic?
- Histoplasma
- Bastomyces
- Coccidioides
- Paracoccidioides
- Sporothrix
Stypes of antimicrobial resistant fungi?
- Aspergillus (Azole)
- Candida (fluconazole)
- Candida auris (fluconazole)
- Ringworm
Can topical azoles be used for pregnancy?
Yes
Terbinafine
MOA
Disrupts synthesis of ergosterol and penetrates to keratin precursor cells (fungicidal)
Griseofulvin
MOA
Prevents fungal cell division and provides good penetration to superficial sites due to transfer of drug cia sweat and trans epidermal fluid loss
Ciclopirox
MOA
Topical lacquer that degrades peroxides within the fungal cells
Nystatin
MOA, Idication
MOA: Alters fungal cell membrane leading to leakage of cell -> cell death
Indication: Oral candidiasis or thrush
Zinc oxide
MOA
Provides physical barrier to water absorption
Selenium sulfide
MOA
Reduction in the turnover of epidermal cells
What are the presentations of Oral candidia? Diagnosis?
Sx: Dysphagia, abnormal odor, dry mouth, abnormal taste
Diagnosis: White plaque that leave an inflamed or bleeding base when scraped off
TYpes of thrush tx?
Acute: 7-14 days
Suppression: not recommended
Tx for Oral Candida?
Fluconazole
Nystatin
Miconazole
Clotrimazole
7-14 days
Presentations of esophageal candida? Diagnosis?
- Can be asymptomatic
- AIDS defining illness (CD4 <100)
Diagnosis: Endoscopy
Tx for Esophageal Candidiasis?
Prophylaxis: Fluconazole, itraconazole
Acute: Fluconazole for 14-21 days
Resistnat: Itraconazole oral solution
Vulvovaginal Candidiasis presentation and diagnosis?
Sx: discharge with little to no odor, pruritis, erythema
Diagnosis:
* Uncomplicated: clincal exam, pH (4-4.5), wet mount
* Complication: reccurent (>4 episodes/wr), severe VVC
Vulvovaginal Candida Tx? Pregnancy?
Uncomplicated:
* Miconazole 2% x 3 days
* Fluconazole PO 1 dose
Complicated:
* Miconazole 2% for 7-14 days
* Fluconazole PO for 3 days and 2 doses
Topical azole x 7 days for pregnancy
Tx for diaper dermatitis?
Nonpharm: Skin care, choice of diaper
Pharm:
* Topical barrier: petrolatum, zinc oxide
* Topical antifungal: nystatin, clotrimazole, miconazole, ketoconazole BID for 2 weeks
Presentation of Intertriginous Dermatitis (Intertrigo)?
Condition of skin folds causes by moisture, friction and absence of air circulation
* Burning, tenderness, prutitus, fissuring
Tx for Intertriginous Dermatitis (Intertrigo)?
Topical agents 1st line: Ketoconzale, Clotrimazole, Miconazole
PO: Fluconazole for 4 wks
What is the difference between tinea barbae and capitis?
Barbae: affects beard and mustache
Capitis: Multiple scaly and/or crusted patches and/or plaque affecting scalp or beard
Tx for tinea barbae/capitis?
Terbinafine PO for 4 wks
Presentation of tinea corporis/cruris
Erythematous plaque with raised leading edge and scaling clearance at the center of a lesion with scattered nodules:
Corporis: body
Cruris: scrotum
Tx for Tinea Corporis/Tinea Cruris?
Topical: Terbinafine 1% cream BID for 3-4 wk
Systemic (failure of topical): Terbinafine PO QD for 2-4 wks
Presentation of tinea pedis
- Interdigital (in between toes)
- Moccasin styles (heel, soles, lateral aspects of feet)
- Vesiculobullous (instep)
Tx for tinea pedis?
Topical (preferred): Terbinafine 1% cream QD 2-4 wks
Systemic: Terbinafine PO QD 2 wk
Nonpharm: Dry cotton socks, loose fitting shoes, drying powder, and drying feet
Presentation and diagnosis of Tinea Unguium/Onychomycosis?
Separation of nail plate, thickening, discoloration, destruction of nail plate
Diagnosis: KOH prep, fungal culture, nail clippings, nail biopsy
Presenation and diagnosis of Tinea versicolor (Pityriasis versicolor)?
Presentation: Superficial infection caused by yeast
* Hypopigmented and/or hyperpigmented patched with very fine scaling affecting sebum-rich areas
Diagnosis: Physical exam
Tx for Tinea Unguium/Onychomycosis Treatment?
Systemic: Terbinafine PO QD for 6 wks (fingernails) or 12 wks (toenails) - avoid in liver dx
Topical: Efinaconazole 10% nail lacquer QD for 48 wks
RF of thrush?
Age, IC
RF of vulvovaginal candida?
IC, Uncontrolled diabetes, debilitation, pregnancy, recurrent infection
RF of diaper rash?
Infrequent diaper changing, infants with diarrhea or chronic stooling, ABX use
RF of intertriginous dermatitis?
- Bedridden
- Obesity
- Incontinence
- Poor hygiene
- Hyperhidrosis
- Immune def
RF of Tinea versicolor (Pityriasis versicolor)?
- Tropical climate/warm weather
- Malnutrition
- PO contraceptives
- Systemic CS
- Immunosuppresants
- Hyperhidrosis
Tinea vesicolor tx?
Topical (first line): Zinc pyrithione shampoo scrubbed onto the affected areas using a mildly abrasive sponge and rinsed off in 3-5 minutes QD x 1-4 wks
Systemic: FLuconazole PO QW 2-4 wks
RF for invasive fungal infection?
- IC host
- CD4 count <200 cells/mm3
- Neutropenia (ANC 500/mm3 or less)
- Nosocomial infections
Antifungals for systemic infections?
- Amphotericin B
- Flucytosine
- Azole
- Echinocandins
- Terbinafine
What are the formulations of amphotericin B?
- Conventional/Amphotericin B deoxycholate (Fungizone IV)
- Liposomal (AmBisome)
ADR of amphotericin?
- Infusion related rx
- Renal toxicity
- Electrolyte Abnormalities due to intracellular leakage and tubular defects
Dosing of amphotericin B in obesity?
If using Adjusted Body Weight to dose, a max of 100 kg is suggested.
If using Actual Body Weight to dose, a max dose of 600 mg is recommended
ADR of azoles?
Visual disturbance, QTc prolongation, hepatotox
Fluconazole: avoid in pregnacy
DDI of azoles?
Inhibitors of CYP2D6, 2C9, 2C19, 3A4, 3A5, and 3A7
Fluconazole has the least amount of interactions
Itraconazole counseling?
Absorption is dependent of gastric pH -> avoid PPI, H2RAs, antiacids
ADR of echocandin?
Peripheral edema, febrile neutropenia
DDI of echinocandiN?
Capsofungin and Micafungin are substrates and inhibitors of CYP3A4
Hepatic dosing: capsofungin
CI and obesity dosing of echinocandin?
CI: pregancy
Obesity dosing: Micafungin: for patients weighing over 115kg, increase dose to 200 mg
ADR of flucytosine?
Nephrotoxicity, hepatotoxicity, bone marrow suppression
Dosing of flucytosine?
Renal dosing: based on GFR
Obesity: Use IBW
Requires therapeutic drug monitoring: 30-80mcg/mL
Presentation and diagnosis of Disseminated Candidiasis/Candidemia?
Sx: fever, sx nonspecific
Diagnosis: histopathology/fungal cultures, blood cultures, serum (1,3) beta-D-glucan, T2 Candida panel
RF of Disseminated Candidiasis/Candidemia?
neutropenia, prolonged hospitalization, central venous catheters, major surgery, broad-spectrum ABX, TPN
Tx for Disseminated Candidiasis/Candidemia?
Preferred: Capsofungin, anidulafungin, micafungin
Azole (alternative): Fluconazole, Voriconazole
Azole and echinocandin resistance: Liposomal amphotericin B 3-5 mg/kg QD
Presentation and diagnosis of aspergillosis?
Acute invasive pulmonary: cough, hemoptysis, pleuritic chest pain, shortness of breath
Chronic pulmonary: mild symptoms
Extrapulmonary invasive: skin lesions, sinusitis, or pneumonia, can disseminate and often rapidly fatal
Aspergillosis in sinuses: fever, rhinitis and headache; can have necrotic lesions, palatal or gingival ulcerations, sinus thrombosis, or pulmonary or disseminated lesions
Aspergillomas: often asymptomatic, may cause mild cough and/or hemoptysis
Diagnosis: CT chest/Xray
Tx for aspergilosis?
Voriconazole PO
Presentation and diagnosis of histoplasmosis?
Presentation:
* Acute primary: resembles a cold and/or pneumonia
* Chronic cavitary: pulmonary lesions and worsening respiratory status
* Progressive disseminated: hepatosplenomegaly, lymphadenopathy, bone marrow involvement, oral/gastrointestinal ulcerations
Diagnosis: Chest X-ray
Tx for Acute primary histoplasmosis?
If infection does not resolve after 1 month:
* Itraconazole 200 mg PO three times daily x 3 days, then twice daily x 6-12 weeks
Tx for chronic cavitary histoplasmosis?
Itraconazole 200 mg PO three times daily x 3 days, then twice daily for 12-14 months
Tx for severe disseminated histoplasmosis?
Liposomal amphotericin B 3 mg/kg IV daily until clinically stable, then itraconazole 200 mg PO three times daily x 3days, then twice daily x 12 months after they become:
* Afebrile
* AIDS patients are given itraconazole indefinitely to prevent relapse or until CD4 count is > 150