Page 635 - TNFlipTest

Toronto Notes 2019 Opportunistic Fungi Cryptococcus spp.
Etiology
• inhalationofairborneencapsulatedyeastfromsoilcontaminatedwithpigeondroppings(C. neoformans) or certain tree species such as Eucalyptus or Douglas fir (C. gatti)
• C.neoformanstendstoaffectimmunocompromisedhostsvs.C.gattiwhichtendstoaffect immunocompetent hosts
Clinical Presentation
• asymptomatic • pulmonary
■ usually asymptomatic or self-limited pneumonitis
■ only 2% of HIV+ patients present with pulmonary symptoms including productive cough, chest
tightness, and fever • disseminated
■ frequently disseminates in HIV+ population
■ CNS: meningitis (leading cause of meningitis in patients with HIV)
■ skin: umbilicated papules that resemble large lesions of Molluscum contagiosum ■ other: bone, lymph nodes, bone marrow, soft tissues, eyes, prostate
Investigations
• serumcryptococcalantigen
• CSFformeningitis:India-inkstain,cryptococcalantigentest,culturetoconfirm
Treatment
• inpatientswithHIVwhohavecryptococcalmeningitisorseverepulmonarydisease:
■ amphotericin B (+ flucytosine) is used in the first 2 wk for induction therapy; limited duration due
to side effects
■ switch to fluconazole for at least 8 wk as consolidation therapy, then continue at lower dose for
prolonged maintenance
Candida albicans
Etiology
• overgrowthofC.albicans(normallyfoundaspartofthemicrobiomeoftheskin,mouth,vagina,andGI tract)
• riskfactorsforovergrowth:
■ immunocompromised state (DM, corticosteroids)
■ ICU patients (broad-spectrum antibiotic use, central venous catheters, TPN)
■ obesity → maceration and moisture in intertriginous areas, pannus, under breasts
Clinical Presentation
• mucocutaneous
■ oral thrush, esophagitis (chest pain, odynophagia), vulvovaginitis (see Gynecology, GY25), balanitis,
cutaneous (diaper rash, skin folds, folliculitis), chronic mucocutaneous ■ small satellite lesions beyond the margin of the rash
• invasive
■ candidemia, endophthalmitis, endocarditis, UTI (upper tract), hepatosplenic disease
Treatment
• thrush:nystatinsuspensionorpastillesformilddisease,fluconazoleforseveredisease
• vulvovaginalcandidiasis:topicalagents(imidazoleornystatin),oralfluconazoleforrecurrentdisease • cutaneousinfection:topicalimidazole
• opportunisticinfectionsinHIV,othersystemicinfections:fluconazoleorechinocandin
• chronicmucocutaneous:azoles
Infectious Diseases ID35
C. gattii sees limited geographical distribution including Vancouver Island, Northern Australia, and Papua New Guinea
India-ink sensitivity for Cryptococcus is only 50% (higher in HIV patients); now replaced by cryptococcal antigen test in most laboratories