Fungal infections - 3

Opportunistic infection in immunocompromised individuals

superficial and deep of the skin, mucosal, lung, systemic

skin

candidiasis (thrush); mucosal and systemic

lung and systemic

Nasal and maxillary sinuses

Lung and brain

lung, oral

• 1. minimal - dermatophyte (skin) ringworm, tinea
• 2. acute - candidiasis
• 3. granulomatous - histoplasmosis

• Histoplasma capsulatum
• It is a mold in soil, bat/bird guano, yeast in tissue

A disease caused by the fungi histoplasma capsulatum that is spread by inhaling spores --> it is a pulmonary disease. The organism is often found in soil.

• 1. mild, flu-like symtpoms
• 2. 2-3 weeks after infection, T-cell mediated granulomatous inflammation, antibody is produced several weeks later
• 3. acute lungs 1%, 2 week duration, calcification of hilar nodes
• 4. chronic lungs immunosuppressed in elderly

• - disseminated (diffused) to extrapulmonary sites.
• - It is rare and found in 2-10% of HIV pts.
• Oral:
• - usually associated with disseminated disease
• - tongue, palate, buccal mucosa, gingiva, floor of the mouth
• - mimics malignancy clincially

It looks like oral cnacer and can be evaluated as non-cancerous because often the patient will also have pulmonary disease.

• granulomatous inflammation
• pseudoepitheliomatous hyperplasia (PEH)
• Periodotc acid Schiff reagent, methenamine silver
• yeasts 1-2u in diameter (this is what mimics cancer)

• tissue sections
• serological testing for antibodies
• detection of H.capsulatum antigen

• actue is usually self limiting
• chronic: amphotericin B, ketoconazole, itraconazole
• Disseminated has the same treatment as chronic

• chronic w/out treatment may be progressive and death in 20%
• disseminated disease mortality 20% w/ treatment

A mold in moist soil that causes blastomycosis

• It is more common in males
• It is rare in immunocompromised individuals
• infections are acquired by inhaling spores (often after rain)

• acute pneumonia: fever, cough, night sweats, chest pain,
• chronic is more common and mimics TB: low grade fever, night sweats, productive cough, infiltrate on chest radiograph (no calcification like histoplasmosis
• Disseminated pulmonary - skin oral (oral lesions mimic malignancy)

• TB - chest radiographs show clear diffuse infiltrate or nodes
• Malignancy - oral lesions look cancrous

• acute and granulomatous inflammation
• pseudoepitheliomatous hyperplasia (PEH)

Blastomyces dermatitidis is 8-20u in diameter with a doubly refractile cell wall w/ broad attachment btw budding cells

PAS and methenamine (Grocott-Gomori) silver special stains

• examine tissue section
• KOH (potassium hydroxide prep) digest cellular matter and leaves KOH crust.
• culture from sputum or non-fixedbiopsy specimen
• DNA probe on mycelia phase 5-7 da culture

• usually no treatment is required
• if seriously ill (more than 2 weeks): itraconazole, ketoconazole, amphotericin B

For the serious illness, there was a 80-90% mortality prior to amphotericin B.

A dimorphic fungus found in soil that causes coccidioidomycosis

• It is acquired via inhalation
• It has a 1-4 week incubation period
• It is more common in blacks and fillipinos
• It causes a disseminated disease (body wide spread) disease in immunocompromised patients

• You find C. immitis with acute and granulomatous inflammation
• Special stains of PAS and methenamine silver are used to ID it

• Tissue specimen
• Cytology
• Culture
• Serological testing and skin testing

In immunosuppresed/life treatening condition of disease: ketoconazole or flucanzole with amphotericin B

The prognosis is pretty good but HIV patiens will need life-long daily antifungal medications.

A fungi who's inhaled spores cause cryptococcosis

It is caused by cryptococcus neoformans and usually manifests as flu-like symptoms.

In immunosuppresed patients it can can become disseminated and spread to the skin, menininges, bones, and prostate.

Oral lesions are rare

200mg fluconazole 2x daily for 8 weeks; then 200mg maintenance for life

• granulomatous inflammation
• 4-6y round to oval mo w/ clear capsule
• It is usually detected with PAS methanmine silver or mucicamine

• biopsy
• culture
• detection of crytococcal antigen in CSF - the meninges are often invovled so some CSF can also be used to find the histological features of the MO

• amphotericin B and flucytosine
• fluconazole and itraconazole

prognosis depends on control of underlying condition and response to antifungal meds

An oppertunistic infection usually caused by saprophytic (an organism that lives on dead material) mo such as Absidia, Mucor, and Rhizopus.

Spores are usually inhalled in a rhinocerebral form. It is poorly controlled in diabetes, leukema, and other systemic disorders.

• Nasal obstruction
• discharge
• facial pain
• headache
• visual distrubance
• facial swelling
• intraolra swelling/ulceration

• Opacification of sinus due to destruction of bone
• It mimics malignancy

Mucromycosis, phycomycosis

• Large right angle branching nonseptate hyphae
• invovles small BV walls and occlude (fungal angilitis)
• Tissue invasion

• Surgical debridement
• Antifungal medication-amphotericin B
• Contorl underlying disease

It has a poor prognosis

The antifungal medication - amphotericin B can cause renal failure.

• An allergic reaction in normal host or invasive in immunocompromised
• It is caused by Aspergillus Saprophytic mo in soil or water (A. Falvus and A. Fumigatus are the most common)

Infection results from inhalation of spores (possible to be spread through hospital ventilation systems)

• allergic symtpoms such as allergic fungal sinusitis
• Low grade infection of sinus such as a fungus ball (aspergilloma)
• Localized pain, swelling, yellow or black ulcer
• Disseminated lung --> CNS, eye, skin, bone, GI (leukemia, corticosteroids)