Sec 30 Fungal Diseases Flashcards
Trichophyton
Skin
Hair
Nails
Microsporum
Skin
Hair
Epidermophyton
Skin
Nails
Preferring humans over other animals as
natural habitat; often epidemic in nature
Anthropophilic
Asexual spore produced by segmentation of
hyphae
Arthroconidia
Melanin in the cell walls of its conidia,
hyphae, or both results in a darkly colored fungus
Dematiaceous
Dermatophyte growth pattern with spores
forming a sheath on the outside of the hair shaft
Ectothrix
Dermatophyte growth pattern with spore
formation within the hair shaft
Endothrix
Characterized by longitudinally arranged hyphae and air spaces within the hair shaft
Favus
Preferring the soil over humans and animals as
natural habitat;
Geophilic
Long, filamentous fungus cells forming a branching
network called mycelium
Hyphae
Asexual large multinucleate spores produced
by vegetative reproduction
Macroconidia
Asexual small spores produced by vegetative
reproduction
Microconidia
Preferring animals over humans as natural habitat;
Zoophilic
Most common geophilic dermatophyte cultured
from humans
Microsporum gypseum
Most commonly used isolation medium for dermatophytes and it serves as the medium on which most morphologic descriptions are based
Sabouraud’s dextrose agar (SDA)
An alternative isolation medium that contains the pH indicator phenol red. The medium turns red when dermatophyte proteolytic activity increases the pH to 8 or above, and it remains amber with the growth of most saprophytes. Nondermatophyte acidic byproducts turn the medium yellow.
Dermatophyte test medium (DTM)
Microconidia - Smooth walled. Used for identification.
Macronidia - Absent or nondiagnostic.
Trichophyton
Microconidia - Absent or nondiagnostic.
Macroconidia - Rough walled. Used for identification.
Microsporum
Microconidia - Absent
Macroconidia - Smooth walled. Used for identification.
Epidermophyton
Colony: Flat feathery colonies with a central fold and yellow to dull gray-green pigment. Yellow to brown reverse pigment.
Microscopic: Numerous thin and thick-walled, club-shaped macroconidia.
Epidermophyton floccosum
Colony: Flat and white to gray with widely spaced radial grooves. Tan to salmon reverse pigment. Salmon-pink pigment on PDA. No growth on polished rice.
Microscopic: Terminal chlamydoconidia and pectinate (comb-like) hyphae.
Microsporum audouinii
Colony: Flat, white to light yellow, coarsely hairy, with closely spaced radial grooves. Yellow to orange reverse pigment. Yellow on PDA. Growth on polished rice.
Microscopic: Numerous thick walled and echinulate spindle shaped macroconidia with terminal knobs and greater than 6 cells.
Microsporum canis
Colony: Flat and granular with tan to buff pigment, no reverse pigment.
Microscopic: Numerous thin-walled pickle shaped macroconidia without knobs and fewer than 6 cells.
Microsporum gypseum
Colony: White to creamy with a cottony, mounded surface. None to light brown reverse pigment. No pigment on PDA. Urease positive, which helps to distinguish it from T. rubrum.
Microscopic: Grape-like clusters of round microconidia, rare cigar-shaped macroconidia, occasional spiral hyphae. Hair perforation positive, which helps to distinguish it from T. rubrum.
Trichophyton interdigitale
Colony: Mounded white center with maroon periphery. Maroon reverse pigment. Cherry red on PDA. Urease negative.
Microscopic: Few tear-shaped microconidia, rare pencil-shaped macroconidia. Hair perforation negative.
Trichophyton rubrum
Colony: Heaped or folded and whitish. Colorless to yellow-tan reverse pigment.
Microscopic: Knobby antler-like hyphae (favic chandeliers), numerous chlamydoconidia.
Trichophyton schoenleinii
Colony: Suede-like center with feathery periphery, white to yellow or maroon color. Reverse pigment usually dark maroon, sometimes none to yellow. Partial thiamine requirement.
Microscopic: Numerous multiform microconidia and rare cigar-shaped macroconidia.
Trichophyton tonsurans
Colony: Small and heaped, although sometimes flat, white to yellowgray. Reverse pigment none to yellow. Requires thiamine and usually inositol for growth.
Microscopic: Chains of chlamydoconidia on SDA. Long and thin “rat-tail” macroconidia with thiamine.
Trichophyton verrucosum
Colony: Waxy and heaped, deep purplish-red. Purple reverse pigment. Partial thiamine requirement.
Microscopic: Irregular hyphae with intercalary chlamydoconidia. No micro- or macroconidia on SDA, rare microand macroconidia with thiamine.
Trichophyton violaceum
Differentiates Trichophyton. interdigitale (positive result) from Trichophyton rubrum (negative result)
Urease test
Differentiates T. interdigitale (positive result) from T. rubrum (negative result)
Hair perforation test
Differentiates Trichophyton species
Nutritional requirement
Differentiates Microsporum species
Growth on polished rice
Identification of isolated fungi is facilitated by subculture on specific media that stimulate sporulation, production of pigment and development of typical morphology.
Potato dextrose agar (PDA) or Borelli’s lactrimel agar (BLA)
Most sensitive test for Onychomycosis
PAS examination
Most specific test for Onychomycosis
Culture
Special stains that highlight hyphae
Periodic acid-Schiff (PAS) stain
Methenamine silver stain
Organisms that will fluoresce on Wood’s light examination
M. canis
M. audouinii
Seborrheic form of tinea capitis since scale is the predominant feature which is seen most commonly with anthropophilic organisms such as M. audouinii or Microsporum ferrugineum
Noninflammatory tinea capitis
Typically caused by the anthropophilic endothrix organisms T. tonsurans and T. violaceum with hairs broken off at the level of the scalp
“Black Dot” Tinea Capitis
Usually caused by zoophilic or geophilic pathogens, such as M. canis, M. gypseum, and T. verrucosum, which is actually a result of a hypersensitivity reaction to the infection
Inflammatory type of tinea capitis
Chronic dermatophyte infection of the scalp rarely involving glabrous skin, and/or nails characterized by thick yellow crusts (scutula) within the hair follicles which leads to scarring alopecia
Tinea favosa or favus
Most common cause of human favus
Trichophyton schoenleinii
Characterized by patchy perifollicular erythema with slight scaling and matting of the hair; produces a yellow-red follicular papule and then a yellow concave crust (scutulum) around a single dry hair
Favus
Exhibits subtle, blue–gray fluorescence along the entire hair with Wood’s lamp examination
Trichophyton schoenleinii
Most commonly caused by the zoophilic strains of T. interdigital affects the face unilaterally and involves the beard area more often than the moustache or upper lip
Tinea barbae
Caused by anthropophiles such as T. violaceum, this form is less inflammatory and resembles tinea corporis or bacterial folliculitis. The active border shows perifollicular papules and pustules accompanied by mild erythema
Superficial type Tinea barbae
Caused by T. interdigitale (zoophilic strains) or T. verrucosum; most common clinical presentation; presents with boggy-crusted plaques and a seropurulent discharge; hairs are lusterless, brittle, and easily epilated to demonstrate a purulent mass around the root
Inflammatory type Tinea barbae
Classic presentation is that of an annular (“ring-worm”-like) or serpiginous plaque with scale across the entire active erythematous border. The border, which may be vesicular, advances centrifugally. The center of the plaque is usually scaly but it may exhibit complete clearing.
Tinea corporals
Superficial and subcutaneous dermatophytic infection involving deeper portions of the hair follicles that presents as scaly follicular papules and nodules that coalesce in an annular arrangement; most commonly by T. rubrum, T. interdigitale, and M. canis; observed on the legs in women who become inoculated after shaving or who apply topical corticosteroids to the involved area
Majocchi’s granuloma
Dermatophytosis of the groin, genitalia, pubic area, and perineal and perianal skin; second-most common type of dermatophytosis worldwide; caused by T. rubrum and E. floccosum
Tinea cruris
Most common presentation of tinea pedis which begins as scaling, erythema and maceration of the interdigital and subdigital skin of the feet, and in particular between the lateral third and fourth and fourth and fifth toes
Interdigital type Tinea pedis
There is patchy or diffuse scaling on the soles and the lateral and medial aspects of the feet, in a distribution similar to a moccasin on a foot. The degree of erythema is variable, and there may also exist few minute vesicles that heal with collarets of scale less than 2 mm in diameter. The most common pathogen is T. rubrum followed by E. floccosum
Chronic Hyperkeratotic (Moccasin) type Tinea pedis
Typically caused by zoophilic strains of T. interdigitale (former T. mentagrophytes var. mentagrophytes), features tense vesicles larger than 3 mm in diameter, vesiculopustules, or bullae on the soles and periplantar areas
Vesiculobullous type Tinea pedis
Tinea pedis with zoophilic T. interdigitale along with rampant bacterial superinfection with Gram-negative organisms produces vesicles, pustules and purulent ulcers on the plantar surface. Cellulitis, lymphangitis, lymphadenopathy and fever are frequently associated.
Acute Ulcerative type Tinea pedis
These inflammatory reactions occur in 4-5% of patients with dermatophytosis at sites distant from the primary inflammatory fungal infections such as tinea pedis or kerion. May appear polymorphic, ranging in morphology from follicular or nonfollicular papules and vesicles of the hands and feet to reactive erythemas including erythema nodosum, erythema annulare centrifugum, or urticaria.
Dermatophyte (Id) reaction
Fungal infection of the nail caused by dermatophytes, nondermatophyte molds, or yeasts with majority of cases caused by T. rubrum and T. interdigitale (90%)
Onychomycosis
Most common form of onychomycosis and begins with invasion of the stratum corneum of the hyponychium and distal nail bed, forming a whitish to brownish-yellow opacification at the distal edge of the nail; hyperproliferation or altered differentiation of the nail bed in response to the infection results in subungual hyperkeratosis
Distolateral subungual type Onychomycosis
Results from infection of the proximal nail fold primarily with T. rubrum and T. megninii and is apparent as a white to beige opacity on the proximal nail plate; gradually enlarges to affect the entire nail and eventuates in subungual hyperkeratosis, leukonychia, proximal onycholysis, and/or destruction of the entire nail; considered a marker for HIV
Proximal subungual type Onychomycosis
Results from direct invasion of the dorsal nail plate resulting in white to dull yellow sharply bordered patches anywhere on the surface of the toenail usually caused by T. interdigitale
White superficial type Onychomycosis
Characterized by firmly attached, hard or gritty, brown–black colored concretions on the hair shaft that vary in size from the microscopic range to a few millimeters in size. Concretions are most commonly noted on frontal portions of the scalp.
Black piedra
Consists of softer and less adherent whitish to beige colored concretions that are discrete or may coalesce into sleeve-like structures along the hair shaft.
White piedra
Etiologic agent: Black piedra
Piedraia hortae
Etiologic agent: White piedra
Trichosporon genus
The second most common cause of vaginitis in women which presents with a vaginal discharge associated with vulvar pruritus, burning, and occasional dysuria or dyspareunia.
Vulvovaginal candidiasis (VC)
Most common form of oral candidiasis which appears as discrete white patches that may become confluent on the buccal mucosa, tongue, palate, and gingivae; scraping the patches exposes a brightly erythematous surface underneath
Acute pseudomembranous candidiasis or thrush
Occurs after sloughing of the thrush pseudomembrane, and is observed most often in the setting of broad-spectrum antibiotic or systemic glucocorticoid therapy and human immunodeficiency virus infection; most common location is on the dorsal surface of the tongue, where depapillated atrophic patches with minimal pseudomembrane formation are noted
Acute atrophic candidiasis (erythematous candidiasis)
Common form of oral candidiasis seen in 24-60% of denture wearers; chronic erythema and edema of the palatal mucosal surface in contact with the dentures is present
Chronic atrophic candidiasis (denture stomatitis)
Characterized by erythema, fissuring, maceration, and soreness at the angles of the mouth; condition is commonly encountered in habitual lip lickers and in elderly patients with sagging skin at the oral commissures
Candidal cheilosis (angular cheilitis or perlèche)
Pruritic eruption on the penis with transient erythema and burning occurring shortly after intercourse; physical findings include white patches on the glans or prepuce and small papules or fragile vesiculopustules on the glans or along the coronal sulcus break to leave erythematous erosions with a collarette of whitish scale
Balanitis
The pruritic eruption appears as macerated red erythematous patches and thin plaques with satellite vesiculopustules. These pustules enlarge and rupture, leaving an erythematous base with a collarette of easily detachable scale that contributes to further maceration and fissuring.
Intertrigo
Refers to interdigital candidal or polymicrobial infection of the hands or feet, usually affects the third or fourth interdigital space, where moisture trapping is thought to underlie the condition
Erosio interdigitalis blastomycetica
Affects the back in bedridden patients, which begins as isolated vesiculopustules containing yeast then spread over occluded regions on the back
Candida miliaria
This is an unusual form of cutaneous candidiasis that manifests as a diffuse eruption beginning as individual vesicles and spreading into confluent areas involving the trunk, thorax, and extremities with associated generalized pruritus
Generalized cutaneous candidiasis
Characterized by chronic, treatment-resistant, superficial candidal infections of the skin, hair, nails, and mucous membranes frequently associated with endocrinopathies including hypoparathyroidism, hypoadrenalism, and hypothyroidism, as well as conditions associated with specific abnormalities in cell-mediated immunity
Chronic mucocutaneous candidiasis
Appears as oval budding cells, elongated filamentous cells connected end-to-end (pseudohyphae), or septate hyphae
Candida sp.
Considered a first line agent in nonneutropenic patients with candidemia or suspected to have invasive candidiasis
Fluconazole
Dimorphic, lipophilic organism that grows in vitro only with the addition of C12–C14 fatty acids such as olive oil and lanolin. Under appropriate conditions, it converts from the saprophytic yeast to the predominantly parasitic mycelial form, which causes clinical disease.
Malassezia furfur
Specific compound synthesized by Malassezia, a yellow compound that absorbs ultraviolet light
Pityriacitrin
Specific compound synthesized by Malassezia, a dicarboxylic acid that inhibits tyrosinase
Azelaic acid
Specific compound synthesized by Malassezia, an aryl hydrocarbon receptor agonist that induces apoptosis in melanocytes
Malassezin
Specific compound synthesized by Malassezia, an indole alkaloid (tryptophan derivative) that fluoresces under 366 nm UV light
Pityrialactone
Specific compound synthesized by Malassezia, ed indole alkaloids that inhibit the neutrophil respiratory burst in vitro in a dose dependent manner and inhibit 5-lipoxygenase activity
Pityriarubins
Presents with scaly oval to round macules scattered over characteristic areas of the body, including the upper trunk, neck, and upper arms. The macules often coalesce forming irregular shaped patches of pigmentary alteration. The color of patches varies from almost white to pink to reddish brown or fawn colored. The scale is characteristically described as dust-like or furfuraceous. Patches may have a wrinkled surface appearance.
Tinea versicolor
Systemic treatment: Tinea versicolor
Oral ketoconazole 200 mg daily for 7 or 10 days
Oral itraconazole 200–400 mg daily for 3–7 days
Oral ketoconazole 400 mg as a single dose
Oral itraconazole 400 mg as single dose
Oral fluconazole 400 mg as single dose
Appears as numerous monomorphic 2-4 mm follicular papules and papulopustules with perifollicular erythema on the upper trunk, neck, and upper arms of young and middle-aged adults
Malassezia (Pityrosporum) folliculitis
Systemic treatment: Pityrosporum folliculitis
Oral Ketoconazole 200 mg daily for 4 weeks
Oral Fluconazole 150 mg weekly for 2–4 weeks
Oral Itraconazole 200 mg daily for 2 weeks
Infections caused by fungi that have been introduced directly into the dermis or subcutaneous tissue through a penetrating injury, such as a thorn prick.
Subcutaneous mycoses
A subcutaneous or systemic fungal infection caused by the dimorphic fungus Sporothrix schenckii with the most frequent site of this infection is the dermis or subcutis
Sporotrichosis
The fungus occurs in the natural environment, presumably in mold (cells growing in a chain) form, but develops as a yeast (cells growing as single cells) in infections.
Sporothrix schenckii
More common form and usually develops on exposed skin sites such as hands or feet. The first sign of infection is the appearance of a dermal nodule that breaks down into a small ulcer. Draining lymphatics become inflamed and swollen, and a chain of soft secondary nodules develops along the course of the lymphatic; these also may break down and ulcerate.
Lymphangitic form of Sporotrichosis
Accounts for about 15% of cases, the infection remains localized to one site, such as the face, and a granuloma develops that subsequently may ulcerate. Satellite nodules or ulcers may form around the rim of the primary lesion.
Fixed form of Sporotrichosis
Treatment: Sporotrichosis
Itraconazole, 200 mg daily
Terbinafine, 250 mg daily
for at least 1 week after clinical resolution
Potassium iodide 4-6 mL tid, and should be continued for 3-4 weeks after clinical cure
Chronic localized infection caused by different species of fungi or actinomycetes, characterized by the formation of aggregates of the causative organisms, known as grains that are found within abscesses. These either drain via sinuses onto the skin surface or involve adjacent bone, causing a form of osteomyelitis. Grains are discharged onto the skin surface via these sinuses.
Mycetoma (Madura foot)
Mycetomas caused by species of fungi
Eumycetomas
Mycetomas caused by aerobic actinomycetes or filamentous bacteria
Actinomycetomas
The earliest stage of infection is a firm, painless nodule that spreads slowly with the development of papules and draining sinus tracts over the surface. Local tissue swelling, chronic sinus formation, and later bone involvement distort and deform the original site of infection.
Mycetoma
Diagnosis: Mycetoma
Direct microscopy of grains
Black grains - fungi
Red grains - actinomycetes
Treatment: Eumycetoma
Ketoconazole 200 mg daily
Itraconazole 200 mg daily
Voriconazole 200–400 mg daily
Over several months
Chronic fungal infection of the skin and subcutaneous tissues caused by pigmented (dematiaceous) fungi that are implanted into the dermis from the environment. They form thick-walled single cells or cell clusters (sclerotic or muriform bodies), and these may elicit a marked form of pseudoepitheliomatous hyperplasia often accompanied by transepidermal elimination of organisms.
Chromoblastomycosis
Etiologic agent: Chromoblastomycosis
Phialophora verrucosa Fonsecaea pedrosoi Fonsecaea compactum Wangiella dermatitidis, Cladophialophora carrionii
The initial site of the infection is usually on the feet, legs, arms, or upper trunk. The initial lesion is often a warty papule that expands slowly over months or years. Lesions may be plaque-like with an atrophic center. The more common verrucous form spreads slowly and locally. Individual lesions may be very thick and often develop secondary bacterial infection. Satellite lesions around the initial site of infection are local extensions of the infection and usually are produced by scratching.
Chromoblastomycosis
Treatment: Chromoblastomycosis
Itraconazole, 200 mg daily
Terbinafine, 250 mg daily
Intravenous amphotericin B (up to 1 mg/kg daily) - extensive cases
Continued until there is clinical resolution of lesions
Infection characterized by the formation of subcutaneous inflammatory cysts or plaques. It is caused by dematiaceous fungi, the most common of which are Exophiala jeanselmei and W. dermatitidis.
Phaeohyphomycosis
Treatment: Phaeohyphomycosis
Surgical excision
Characterized by the appearance of keloid-like skin lesions on exposed sites. Cannot be cultured in vitro; it is caused by a fungus, Lacazia loboi, that forms chains of rounded cells in tissue, each joined by a small tubule.
Lobomycosis
Treatment: Lobomycosis
Surgical excision
Rare tropical subcutaneous mycosis characterized by the development and spread of a chronic, firm swelling involving subcutaneous tissue most often caused by Basidiobolus ranarum (B. haptosporus), is more common in children and Conidiobolus coronatus, is seen in adults
Subcutaneous mucormycosis
The early infection starts in the region of the inferior turbinates of the nose. Spread involves the central part of the face, and once again, the swelling is hard and painless. It may cause very severe deformity of the nose, lips, and cheeks.
Subcutaneous mucormycosis
Treatment: Subcutaneous mucormycosis
Ketoconazole 400 mg daily
Itraconazole 100-200 mg daily
Chronic infection caused by the organism Rhinosporidium seeberi, which causes the development of polyps affecting the mucous membranes. The main site affected is the nasal mucosa, but the conjunctival mucosa also may be affected.
Rhinosporidiosis
Dimorphic fungi with yeast 2-5 μm in diameter
Histoplasma capsulatum var. capsulatum
Dimorphic fungi with yeast 10-15 μm in diameter
Histoplasma capsulatum var. duboisii
Patients are often exposed to large quantities of spores such as may be encountered in a cave or after cleaning a bird-infested area. Patients present with cough, chest pain, and fever, often with accompanying joint pains and rash - toxic erythema, erythema multiforme, or erythema nodosum. On chest X-ray, there is often diffuse mottling, which may calcify with time.
Acute Pulmonary Histoplasmosis
Usually occurs in adults and presents with pulmonary consolidation and cavitation, closely resembling tuberculosis. Skin involvement is not seen.
Chronic Pulmonary Histoplasmosis
There is widespread dissemination to other organs such as the liver and spleen, lymphoreticular system, and bone marrow. Patients present with progressive weight loss and fever. This form is the type that is most likely to occur in untreated AIDS patients, who often develop skin lesions as a manifestation of disseminated infection. There are papules, small nodules, or small molluscum-like lesions that subsequently may develop into shallow ulcers.
Acute Progressive Disseminated Histoplasmosis
May appear months or years after a patient has left an endemic area. The most common clinical presenting features are oral or pharyngeal ulceration, hepatosplenomegaly or adrenal insufficiency (Addison disease) due to adrenal infiltration. The mouth ulcers are often large, irregular, and persistent and may affect the tongue as well as the buccal mucosa.
Chronic Progressive Disseminated Histoplasmosis
Rare and follows inoculation of the organism into the skin, for instance, after accidental laboratory- or postmortem room-acquired infection. The primary lesion is a nodule or indurated ulcer, and there is often local lymphadenopathy.
Primary Cutaneous Histoplasmosis
An intracellular parasite often seen in macrophages. The cells are small (2-4 μm in diameter) and oval in shape with small buds.
Histoplasma
The most common clinically involved sites are the skin and bone, although lymph nodes and other organs, including the lungs, may be affected. Skin lesions range from small papules resembling molluscum contagiosum to cold abscesses, draining sinuses, or ulcers.
African Histoplasmosis
Treatment: Histoplasmosis
Oral itraconazole (200–400 mg daily) Intravenous amphotericin B (up to 1 mg/kg daily)
Chronic mycosis caused by the dimorphic pathogen Blastomyces dermatitidis. Its chief sites of involvement are the lungs, but disseminated forms of the infection may affect skin, bones, central nervous system, and other sites.
Blastomycosis
Very rare and follows trauma to the skin and the subsequent introduction of fungus. After inoculation, an erythematous, indurated area with a chancre appears in 1-2 weeks with associated lymphangitis and lymphadenopathy. The early lesion is a papule or nodule, which may ulcerate and discharge pus. With time, this enlarges to form a hyperkeratotic lesion, often with central ulceration and/or scarring.
Primary cutaneous blastomycosis
KOH: thick-walled, rounded refractile spherical cells with broad-based buds
Culture: grows as a mycelial fungus at room temperature; produces small, rounded, or pear-shaped conidia. At higher temperature and on enriched media, it produces yeast forms with the characteristic buds.
Blastomycosis
Treatment: Blastomycosis
Itraconazole (200–400 mg daily)
Voriconazole
For 6 months
Amphotericin B (up to 1 mg/kg daily) - for extensive
Infection caused by the fungal species Coccidioides immitis and Coccidioides posadasii. They show an unusual form of dimorphism, with a mold form at room temperature and the development of large, spore-containing structures, spherules, in infected tissue.
Coccidioidomycosis
Most common clinical type, presents as a chest infection with fever, cough, and chest pain. Complications such as pleural effusion may occur. Erythema multiforme or erythema nodosum, often accompanied by arthralgia or anterior uveitis, occurs from the third to the seventh week in about 10-15% of patients and is more common in females. Sometimes an early, generalized, macular and erythematous rash is seen in some patients.
Primary pulmonary form of Coccidioidomycosis
Presents with chronic cough and resembles tuberculosis. Skin lesions normally do not occur in this phase.
Chronic pulmonary form of Coccidioidomycosis
After inoculation, there is an indurated nodule that develops 1–3 weeks after local trauma. This is followed by regional lymphadenopathy. This develops in <0.5% of infected individuals. It is mainly seen in patients from certain ethnic backgrounds.L esions may develop in the skin, subcutaneous tissues, bones, joints, and all organs. The skin lesions are papules, nodules, abscesses, granulomas, ulcers, or discharging sinuses in which there is underlying bone or joint disease. Some lesions appear as flat plaques with central atrophy.
Disseminated coccidioidomycosis
KOH: porecontaining spherules; large (up to 250 μm)
Culture: mycelial, fast growing, white, and cottony.
Coccidioidomycosis
Treatment: Coccidioidomycosis
Amphotericin B (1 mg/kg daily)
Itraconazole (200–400 mg daily)
Fluconazole (200–600 mg daily)
Infection caused by a dimorphic fungus that causes a respiratory infection with a tendency to disseminate to the mucous membranes and lymph nodes.
Paracoccidioidomycosis
KOH: round yeasts with a characteristic form of multiple budding in which a parent cell is surrounded by large numbers of smaller buds.
Culture: dimorphic which produces a cottony mycelial-phase growth on primary isolation at room temperature and yeast phase can be induced on enriched media such as brain-heart infusion agar at 37°C
Paracoccidioidomycosis
Treatment: Paracoccidioidomycosis
Itraconazole for 3-6 months
Infection found in Southeast Asia caused by P. marneffei is a member of the common genus Penicillium which shows an unusual pattern of dimorphism in that it develops yeast-like cells that reproduce with septal formation, dividing the cells into two. It is inhaled via the lungs, and it is not known whether there is a primary cutaneous form of the infection. Patients with AIDS appear to be particularly susceptible to this infection.
Penicilliosis
Methenamine silver: yeast-like cells that are divided by a septum
Culture: green or grayish mold that produces typical conidiophores and a diffusible red pigment
Penicillium marneffei
Treatment: Penicilliosis
Itraconazole (200–400 mg daily)
Amphotericin B
Infection caused by the encapsulated yeast C. neoformans. Main portal of entry is through inhalation into the lungs, the disease usually presents with signs of extrapulmonary dissemination such as meningitis. Cutaneous lesions can develop as a result of dissemination. It is associated with HIV infection.
Cryptococcosis
Most common clinical manifestation of Cryptococcosis
Meningoencephalitis
Presents with acneiform papules or pustules progressing to warty or vegetating, crusted plaques, ulcers, and hard infiltrated plaques or nodules are characteristic of widespread systemic infection.
Cryptococcosis
Large (5–15 μm), budding cells with capsules that are best observed by direct microscopy of India ink or Nigrosin mounts
Cryptococcosis
Treatment: Cryptococcosis
IV amphotericin B combined with flucytosine (non AIDS)
Amphotericin B with or without flucytosine for 10-14 days followed by long-term Fluconazole
