Module 3.2 Medical Mycology (Superficial, Cutaneous, and subcutaneous fundal infections).pdf

3.2 Superficial, Cutaneous, Subcutaneous Fungal Infections • • • • OUTLINE Superficial Mycoses A. Pityriasis versicolor B. Tinea nigra C. Black piedra D. White piedra III. Cutaneous Mycoses D. Trycophyton sp. E. Microsporum sp. F. Epidermophyton sp. G. Tinea capitis II. I. A. Tinea pedis B. Tinea...

3.2 Superficial, Cutaneous, Subcutaneous Fungal Infections • • • • OUTLINE Superficial Mycoses A. Pityriasis versicolor B. Tinea nigra C. Black piedra D. White piedra III. Cutaneous Mycoses D. Trycophyton sp. E. Microsporum sp. F. Epidermophyton sp. G. Tinea capitis II. I. A. Tinea pedis B. Tinea corporis C. Tinea cruris Subcutaneous Mycoses A. Sporotrichosis B. Chromoblastomycosis C. Mycetoma D. Rhinosporidiosis • Legend: Book Previous Trans To Remember/Trans head note ★ OBJECTIVES • Discuss the etiologic agents and characteristics of superficial, cutaneous and subcutaneous fungal infections • Identify the diagnostic methods, treatment and preventive measures for these infections • Fungi o is a diverse group of organisms; they can be saprophytic (live on decaying organic matter) or parasitic. o They are eukaryotic organisms. o Remember that they have a very thin membrane which is composed of chitin or ergosterol. o Antifungal drugs should target this component of the membrane. To be able to get food source, it does not engulf but it sends out enzymes to degrade the environment and absorb the nutrients. • Mycosis is identified based on the location where the infection is: o Cutaneous if it's limited to the epidermis particularly in the stratum corneum. o Hair shaft is where your superficial mycotic infections are. o Subcutaneous if layer other than the skin. • • I. SUPERFICIAL MYCOSES Limited to the stratum corneum and hair shaft Infections are often so innocuous that patients are often unaware of their condition Innocuous - very harmless-not illicit immune response or symptoms at all Cosmetic problems ( most common reason why patients visit doctors) Do not elicit immune response, nor discomfort COMMON INFECTIONS Infections Pityriasis versicolor Seborrheic dermatitis including Dandruff and Follicular pityriasis Tinea nigra White piedra Black piedra • • • • • Review: • Mycosis - means human fungal diseases • • • Causative agents Malassezia furfur TOPNOTCH: Spaghetti and meatballs Incidence Common Exophiala werneckii Trichosporon beigelii Piedraia hortae Rare Common Rare BIO 125 MEDICAL MICROBIOLOGY aka Tinea versicolor aka AN-AN “Versicolor” – can be light, dark, pink or tan Caused by Malassezia furfur (Pityrosporum orbiculare) • Lipophilic yeast living on the skin as part of the normal flora • Hence very common skin infection Exist in budding yeast, occasionally hyphal forms DIMORPHIC =it exists in two forms Yeast: grow in normal body temp-37°C; Molds: grow at lesser temp around 25°C Characterized by well-demarcated white, pink or brownish lesions – versatile in color, often coalescing Scales easily giving it a chalky appearance – ( pag hinawakan mo siya, flaky) Color varies according to the normal pigmentation of the patient, exposure of the area to sunlight, and the severity of the disease Lesions occur on the trunk, shoulders and arms, rarely on the neck and face Discrete, serpentine, hyper-, or hypopigmented maculae occur on the skin, usually on the chest, upper back, arms, or abdomen Fluoresce a pale greenish color under Wood's UV light Young adults are affected most often, but the disease may occur in childhood and old age Fig 1. Different skin manifestation of Pityriasis versicolor. Chronic mild superficial infection of the stratum corneum. Caused by Malassezia globosa, Malassezia restricta, and other members of the Malassezia furfur complex. Lesions are chronic and occur as macular patches of discolored skin that may enlarge and coalesce. Scaling, inflammation, and irritation are minimal. DIAGNOSIS Figure 2. Budding yeast (red arrow) vs. Hyphal forms (blue arrow). Direct Microscopy: A. Pityriasis Versicolor 3.2 Superficial, Cutaneous, Subcutaneous Fungal Infections 1 of 11 • Skin scrapings in 10% KOH, glycerol and Parker ink solution • Show characteristic clusters of thick-walled round, budding yeast- like cells and short angular hyphal forms “spaghetti and meatballs” = dimorphic!!!! Stained with calcoflour white Short unbranched hyphae and spherical cells Why KOH: because it dissolves the material binding the skin cells together allowing easy visualization of the fungus. TOPNOTCH: Malassezia is extremely difficult to propagate in laboratory culture and is culturable only in media enriched with C12- to C14- sized fatty acids. TREATMENT • Ketoconazole shampoo • Moisten the area with water then apply the shampoo, leave for 810mins then rinse off again, everyday for 2weeks ( interfere with ergosterol synthesis in the fungal membranes) • Zinc pyrithione shampoo or selenium sulfide lotion applied daily for 10-14 days or the use of propylene glycol 50% in water twice daily for 14 days Easily available-mas ginagamit Figure 3. (L) Brown macule produced by Tinea nigra (R) Yeast form of Tinea nigra. Budding is almost more than 50%. DIAGNOSIS • Skin scrapings should be examined using 10% KOH and Parker ink or calcofluor white mounts • Culture: Sabouraud's dextrose agar Sabourauds dextrose agar or SDA contains: glucose, modified peptone water and has a low acidic pH and antibiotics ( 2 weeks treatment- medyo matagal kasi normal flora of the skin) • Severe cases with extensive lesions, or in cases with lesions resistant to topical treatment: o Oral ketokonazole (400 mg single dose or 200 mg/day for 5-10 days) or o Itraconazole (200 mg/day for 5-7 days) • • • • • • • • B. Tinea Nigra Causative agent: Hortaea werneckii Occur in soil, compost, humus and on wood in humid tropical and sub-tropical regions Common in tropical regions of Central and South America, Africa, South-East Asia and Australia Grows as yeast →Older hyphae with mycelia and conidia Recall- conidia spores that forms asexually at the tip of the hyphae Produce melanin black or brown color Characterized by brown to black macules which usually occur on the palmar aspects of hands and occasionally the plantar and other surfaces of the skin Different from birthmark Lesions are non-inflammatory and non-scaling Familial spread of infection has also been reported Madaling ispread, hawakan mo yung doorknob can spread the infection Figure 4. Micrograph of the fungus Hortaea werneckii and agar plate with the fungi. TREATMENT • Topical treatment with Whitfield's ointment- Combination of benzoic acid and salicylic acid (benzoic acid compound) • Oral imidazole agent twice a day for 3-4 weeks is effective Tinea nigra will respond to treatment with keratolytic solutions, salicylic acid, or azole antifungal drugs. • • • • C. Black Piedra Caused by Piedra hortae Common in Central and South America and South-East Asia Forms hard black nodules on the shafts of the scalp, beard, moustache, axillary and pubic hair ( Plaques on the scalp, usually wala na buhok yung area) Affects young adults and epidemics in families have been reported following the sharing of combs and hairbrushes Or Tinea nigra palmaris Superficial chronic and asymptomatic infection of the stratum corneum. Skin scrapings from the periphery of the lesion will reveal branched, septate hyphae and budding yeast cells with melanized cell walls. Figure 5. (Top) Alopecia caused by the Black piedra (Bottom) Hard nodule seen. 3.2 Superficial, Cutaneous, Subcutaneous Fungal Infections 2 of 11 DIAGNOSIS • Clinical Feature: o Epilated hairs with hard black nodules present on the shaftusually sa scalp, cut na yung hair, putol putol na. • Direct Microscopy: o 10% KOH and Parker ink or calcofluor white o Identify nodules (pigmented mass containing asci) Figure 8. Trichosporon beigelii grown in a slant culture. • Microscopic examination: 10% KOH and Parker ink or calcofluor white mounts shows hyphae that develops into arthroconidia (barrel shape). • Figure 6. Hair shaft with Black Piedra. ( On the hair shaft, is actually a group of nodule, nakakapit siya dun sa hair containing the spores) Culture: Sabouraud’s dextrose agar TREATMENT • Shave or cut the hairs short • Terbinafine Antifungal, inhibits ergosterol through inhibition of squalene epoxidase which is the basic component of fungal cell membrane o 250 mg tablet a day for 6 weeks • • • D. White Piedra Infection of the hair shaft caused by Trichosporon beigelii Common in young adults of tropical or subtropical regions Localized to the axilla or scalp but may also be seen on facial hairs and sometimes pubic hair Figure 9. Barrel-shaped arthroconidia (red arrow). MANAGEMENT • Shaving the hair • Topical application of an imidazole agent may be used to prevent reinfection • Selenium sulfide shampoo Selsun blue shampoo: has antimycoses action ( wet your hair first, then put the shampoo and leave it on for then minutes, then wash) • • Figure 7. White Piedra in the hair. ( Parang lisa, which is firmly attached sa hair pero ang itsura niya is like dandruff pero pag pinagpag mo unlike dandruff na nalalaglag, this one hindi kasi firmly adherent nga sa hair) • Irregular, soft, white or light brown nodules, 1.0-1.5 mm in length, firmly adhering to the hairs DIAGNOSIS • Cultures in Sabouraud's dextrose agar are pasty and white develop deep radiating furrows and become yellow and creamy • II. CUTANEOUS MYCOSES Dermatophytoses involves the skin and its appendages (hair, nails) Infects only the keratinized tissue, skin, hair and nails Sa superficial skin lang, sa cutaneous involve ang skin as well as appendages including hair and nails Dermatophytes or keratinophilic fungi, produce extracellular enzymes (keratinases) which are capable of hydrolyzing keratin Etiology (M E T): → Microsporum → Epidermophyton → Trichophyton TOPNOTCH: Secretes the enzyme keratinase, which digests keratin CUTANEOUS MYCOSES Disease Causative Agent Dermatophytosis Dermatophytes Ringworm of the → Microsporum, scalp, glabrous skin → Epidermophyton and nails → Tricophyton, Candidiasis of skin, Candida albicans and related mucous species membranes and 3.2 Superficial, Cutaneous, Subcutaneous Fungal Infections Incidence Common Common 3 of 11 nails Dermatomycosis • • • • walled, 4- to 6-celled macroconidia. Non-dermatophyte molds → Hendersonula toruloidea → Scyralidium hyalium → Scopulariopsis Rare A. Trichophyton sp. Infect skin, hair and nails Conidia are large (macroconidia), smooth, thin- wall, septate (010 septa), and pencil-shaped REMEMBER: PENCIL-SHAPED MACROCONIDIA (Narrow and long shape, cigar-shaped); o Colonies are a loose aerial mycelium that grow in a variety of colors Identification requires special biochemical and morphological techniques • • • • C. Epidermophyton sp. Epidermophyton floccosum Infect skin and nails and rarely hair Form yellow-colored, cottony cultures and are usually readily identified by the thick, bifurcated hyphae with multiple smooth, club- shaped macroconidia REMEMBER: o CLUB-SHAPED MACROCONIDIA, o 2 hyphae because of the bifurcation- ( mukha siyang cotton buds actually); rare in hair Only pathogen in this genus. produces only macroconidia —> smooth-walled, clavate, 2- to 4-celled, and formed in small clusters Colonies are usually flat and velvety with a tan to olive-green tinge. Figure 10. Narrow and long shape (Cigar-shaped) macroconidia. T. rubrum o White, cottony surface and a deep red, non-diffusible pigment when viewed from the reverse side of the colony o Microconidia are small and piriform (pear-shaped) T. tonsurans o Flat, powdery to velvety colony on the obverse surface that becomes reddish-brown on reverse o Microconidia are mostly elongated Trichophytin o A crude antigen preparation that can be used to detect immediate- or delayed-type hypersensitivity to dermatophytic antigens • • • B. Microsporum sp. Infect skin and hair, rarely nails. Identified on the scalp because infected hairs fluoresce a bright green color when illuminated with a UV-emitting Wood's light The loose, cottony mycelia produce macroconidia which are thick-walled, spindle- shaped, multicellular, and echinulate (spiny) Figure 12. Epidermophyton floccosum (bifurcated hyphae with multiple smooth, club-shaped macroconidia) seen under the microscope. REMEMBER: TRICHOPHYTON: • Skin, hair nails • Pencil-shaped macroconidia MICROSPORUM: • Only skin and hair • Spindle-shaped macroconidia EPIDERMOPHYTON: • Only skin and nail • Produce only macroconidia • Club-shaped macroconidia CLASSIFICATIONS OF DISEASES CAUSED BY DERMATOPHYTES ANATOMIC LOCATION: Tinea pedis Tinea capitis Tinea corporis Tinea cruris Figure 11. Micrograph of Microsporum sp. Microsporum canis o Colony with a white cottony surface and a deep yellow color on reverse o Thick-walled, 8- to 15-celled macroconidia frequently have curved or hooked tips Microsporum gypseum o Produces a tan, powdery colony and abundant thin- • • • • • • “Athlete’s foot” Infection of toe webs and soles of feet Found on the head Occurring anywhere on the body “Jock itch” Infection of the groin, perineum or perianal area ECOLOGIC LOCATION: Anthropophilic Zoophilic • associated with humans only; transmission from man to man is by close contact or through contaminated objects • associated with animals; transmission to man is by close contact with animals (cats, dogs, cows) or with contaminated products 3.2 Superficial, Cutaneous, Subcutaneous Fungal Infections 4 of 11 Geophilic • Usually found in the soil and are transmitted to man by direct exposure • • • Sharply marginated scale distributed along lateral borders of feet, heels and soles ( shoe-pattern) Vesicle and erythema are present at the margins Often associated with onychomycosis (nail fungal infection) Tinea unguium o Onchomycosis o Nail infection as a result of prolonged tinea pedis. o With hyphal invasion, the nails become yellow, brittle, thickened, and crumbly. o One or more nails may be involved Figure 13. Clinical classification of Dermatophytoses. • • • • • D. Tinea pedis Trichophyton rubrum T. interdigitale Epidermophyton floccosum Shoes ideal environment for fungus to grow due to moisture Public shower, gyms, swimming pool are common sources of infection. Figure 15. Lesion seen on borders of feet, heels, and soles 3. VESICULOBULLOUS • Vesicles or bullae usually on the instep • May be pruritic or painful • Represent a delayed hypersensitivity immune response to a dermatophyte CLINICAL PATTERN • • → Interdigital, → Mocassin, → Vesiculobullous type Other varieties are the vesicular, ulcerative, and moccasin types, with hyperkeratosis of the sole Difficult to permanently cure and often recur Athlete’s foot Most prevalent of all dermatophytes Usually as a chronic infection of the toe webs. itching between the toes & development of small vesicles rupture (discharge a thin fluid) skin of the toe webs becomes macerated and peels cracks appear that are prone to develop secondary bacterial infection. Chronic: peeling and cracking of the skin are the principal manifestations, accompanied by pain and pruritus. Figure 16. Bullous lesion seen on borders of feet. ( recommended to wear open shoes or use dry foot powders/tawas for prevention because this fungi lives in moisture on the skin) TREATMENT • 1. INTERDIGITAL • Most common, presents with scaling and redness between the toes and may have maceration Figure 14. Scaling toes. 2. • MOCASSIN Known as Chronic hyperkeratotic type • • • • • Hygiene o o o o Dry the area after bathing Change socks daily and alternate shoes worn Consider wearing open shoes e.g. sandals Use alum solution or foot powder to keep the feet dry Topical antifungals- apply until there is resolution o Imidazole: Fungistatic (stops fungi growth) o Allylamines: Fungicidal (kills fungi) o Ciclopirox: Fungicidal and fungistatic E. Tinea corporis and Tinea cruris “Ringworm”; “BUNI” Dermatophytes of the skin especially the trunk and limbs Affects all age group Asymmetric distribution ( identify first the primary lesion, kasi kung hindi tuloy tuloy parin ang infection) 3.2 Superficial, Cutaneous, Subcutaneous Fungal Infections 5 of 11 • • Margin of the lesion is the most active, central clearing seen Tinea cruris or “jock itch” has a similar presentation but appears in the groin Clearing, scaly center surrounded by a red advancing border that may be dry or vesicular. Dermatophyte grows only within dead, keratinized tissue Fungal metabolites, enzymes, and antigens diffuse through the viable layers of the epidermis to cause erythema, vesicle formation, and pruritus. Infections with geophilic and zoophilic dermatophytes produce more irritants and are more inflammatory than anthropophilic species. As hyphae age form chains of arthroconidia. Lesions expand centrifugally and active hyphal growth is at the periphery Trichophyton equinum Trichophyton verrucosum Figure 19. “Kerion” lesion caused by T. verrucosum following contact with cattle ( starts as abscess, then becomes kerion. Pag nakakita kayo ng kerion, di niyo malilimutan yun kasi it looks like aligue pasta crab fat pasta) ENDOTHRIX HAIR INVASION o Invasion of the hair shaft; this area becomes filled with fungal hyphae and chains of arthroconidia o Cuticle of the hair remains intact and infected hairs do not fluoresce under Wood's ultraviolet light o Caused by T. tonsurans and T. violaceum Figure 17. Annular lesion with central clearing. LABORATORY DIAGNOSIS • • Even if the KOH is negative, a culture may be positive for the fungi Cultures done when considering long-term treatment TREATMENT • • • Topical antifungals Oral antifungals are indicated if: o There is poor response to topical agents for 2 months already o Source of infection is an animal o Involves a large area ( if buong katawan na ang infection) F. Tinea capitis Dermatophytosis of the scalp Figure 20. Endothrix tinea capitis (left) caused by T. tonsurans and "black dots" tinea capitis (right) caused by T. violaceum. • Favus o Caused by T. schoenleinii, produces favus-like crusts or scutula and corresponding hair loss o Looks similar to a maculosquamous eruption ECTOTHRIX INVASION o Characterized by the development of arthroconidia on the outside of the hair shaft Figure 21. Crusts or scutula and corresponding to hair loss ( usually starts as crust-like lesion that looks like sea corals and patches na walang buhok) Figure 18. Hair cuticle is destroyed and infected hairs usually fluoresce a bright greenish yellow colour under Wood’s light. o Common agents include Microsporum canis Microsporum gypseum TYPES OF DERMATOPHYTIC INFECTION 1. The Acute or Inflammatory type of infection • Associated with CMI to the fungus • Generally, heals spontaneously or responds well to treatment. 2. The Chronic or Non-inflammatory infection • Associated with a failure to express CMI to the fungus at the site of infection 3.2 Superficial, Cutaneous, Subcutaneous Fungal Infections 6 of 11 • Relapsing and responds poorly to treatment *CMI: cell mediated immunity ( you really need to know what the cause is. You really need to have very good physical examination kasi mamaya hindi mo pala nakita yung primary lesion, mahahawa at mahahawa lang yung ibang parte ng katawan mo.) • • • Terbinafine (Lamisil) - oral, topical Echinocandins (Caspofungin): o Inhibiting β (1,3)-D-Glucan of the fungal cell wall For infections involving the scalp and particularly the nails: Griseofulvin (inhibits microtubule formation) RECOMMENDED TREATMENT FOR TINEA INFECTIONS IDENTIFICATION REACTION • May show a lesion (ringworm) often on the hands, from which no fungi can be recovered or demonstrated • Skin lesions on the dominant hand are secondary to immunological sensitization to a primary infection located somewhere else (e.g. feet) • Secondary lesions will not respond to topical treatment but will resolve if the primary infection is successfully treated If you found a ringworm at the palmar side of the hand at hindi siya gumagaling at all, baka meron pang ibang source of infection. Try to look at the other parts of the body. Kasi baka yung source ng palmar lesion mo, nasa paa. Kamot pala ng kamot yung patient. Di mo natreat yung sa paa, kaya hindi din nagheal yung sa kamay. DIAGNOSIS • • • Skin Scrapings, nail scrapings and epilated hairs o Using a blunt scalpel, tweezers, or a bone curette, firmly scrape the lesion, particularly at the advancing border o In vesicular tinea pedis, tops of any fresh vesicles should be removed o In patients with suspected dermatophytosis of nails (onychomycosis) o Nail should be pared and scraped using a blunt scalpel until the crumbling white degenerating portion is reached o Any white keratin debris beneath the free edge of the nail should also be collected KOH mount showing typical dermatophyte hyphae breaking up into arthroconidia Cultures o Selective media – Sabouraud's dextrose agar containing cycloheximide ( inhibits growth of saphrophytic fungi but allows pathogenic ones) and chlorampenicol ( inhibits growth of the contaminating bacteria) => incubate at 25° C o Identification based on the conidia III. SUBCUTANEOUS MYCOSES Chronic, localized infections of the skin and subcutaneous tissue following the traumatic implantation of the etiologic agent • In general, the lesions become granulomatous and expand slowly from the area of implantation • Extension via lymphatics is slow except for Sporotrichosis • Figure 23. Causative organisms of subcutaneous mycoses. Figure 22. Conidia seen in culture media. TREATMENT • • Tolfnatate (Tinactin) o available over the counter - topical Azole o Inhibits cytochrome 450 dependent enzyme systems at the demethylation step from lanosterol to ergosterol • A. Sporotrichosis Caused by Sporothrix schenckii Thermally dimorphic fungus o Very common saprophytic fungus that decomposes plant matter in soil o Rose-gardener’s disease ( for example nandoon yung fungi sa tinik then natusok yung gardener, papasok siya hanggang subcutaneous) Common in gardeners or yung mga nag-aarange ng flowers o Incubation period: 8-30 days 3.2 Superficial, Cutaneous, Subcutaneous Fungal Infections 7 of 11 Associated with variety of plants (grasses, trees, sphagnum moss, rose bushes) At ambient temperature (25°C): Grows as mold, producing branching, septate hyphae and conidia In tissue or in vitro (35-37°C): Small budding yeast Varieties includes: Lymphangitic or lymphocutaneous, Fixed or endemic, Mycetoma like and Cellulitic CLINICAL VARIETIES 1. Lymphangitic form • Contaminated plant matter penetrates the skin and the pathogen forms a nodule, then spreads to nearby lymph nodes • Common, exposed sites • • • LABORATORY DIAGNOSIS Figure 26. Direct microscopy of Sporotrichosis ( madaling tandaan: Rose-gardener disease - mukhang flower sa direct microscopy due to clustering) • • • • • Figure 24. Lymphangitic form commonly seen in exposed areas. • • • • • • Widely disseminated lesions (kidney, joints, meninges, skin) Immunosuppressed patients If untreated – fatal Dermal nodule o pustule o ulcer Multiple inflamed nodules Swollen extremities Chronic - regional lymph nodes swollen Thin purulent discharge Primary lesion may heal spontaneously Fluorescent antibody HPE (Histopathologic Examination)-multiple tissue sections Culture: Pus/biopsy PCR Identification is routinely done through HPE and clinical microscopy Routine agar media at room temperature: young colonies are blackish and shiny, becoming wrinkled and fuzzy with age Identification is confirmed by growth at 35°C and conversion to the yeast form Strains vary in pigmentation from shades of black and gray to whitish Gomori methenamine silver: stains the cell wall black Periodic Acid-Schiff: imparts red color to the cell wall Produces branching, septate hyphae and distinctive small conididia, directly clusterered at the ends of tapering conidiophores May also form larger conidia directly from the hyphae Asteroid body is often seen in tissue, particularly in endemic areas such as Mexico, South Africa, and Japan Figure 24. Multiple inflamed nodules with swollen extremity 2. Fixed/ Endemic form • Less common - 15% • Acneiform, nodular, ulcerated, verrucous • Infiltrated plaques, red scaly patches Figure 27. Direct Microscopy. Consist of a central basophilic yeast cell surrounded by radiating extensions of eosinophilic material, which are depositions of antigen-antibody complexes and complement. TOPNOTCH: • Definitive diagnosis of sporotrichosis at any site requires the isolation of S schenckii in a specimen culture from a normally sterile body site. • The organism can be recovered with fungal culture from sputum, pus, subcutaneous tissue biopsy, synovial fluid, synovial biopsy, bone drainage or biopsy, and cerebrospinal fluid (CSF). Figure 25. Ulcerative lesion 3. Systemic form ( rare) • Follows inhalation • Develop anywhere • Chronic lung nodules cavitation TREATMENT • • Potassium iodide: Saturated uncomplicated infection) Itraconazole : 100-200mg solution ( 3.2 Superficial, Cutaneous, Subcutaneous Fungal Infections especially if 8 of 11 • • • • • • • Fluconazole : 400 mg Ketaconazole Terbinafine : 250 – 500 mg Amphotericin B: Destroys the membrane ergosterol Hyperthermia : 42C ( bakit? these fungi grows best around 25 to 37 degrees Celcius. If masyado tinaas ang temperature, they will not grow) Pregnancy – Azoles are contraindicated AIDS - Amphotericin B + Itraconazole B. Chromoblastomycosis Verrucous dermatitis Slow growing lesions Multiple etiologies: o Fonsacaea pedrosoi, o Phialopora verrucosa, o Fonsecaea compacta, o Wangiella dermatitidis, o Cladosporium carrionii Phialophora verrucosa • Conidia are produced from flask –shaped phialides with cup-shaped collarets • Mature, spherical to oval conidia are extruded from the phialide and usually accumulate around it. Fonsecaea pedrosoi • Polymorphic and may exhibit: o Phialides o Chains of blastoconidia (similar to Cladosporium sp.) o Sympodial, rhinocladiella-type conidiation Rhinocladiella aquaspera • Produces lateral or terminal conidia from lengthening conidiogenous cell, a sympodial process • Conidia are elliptical to clavate Cladophilaophora carrionii • Produce branching chains of conidia by distal (acropetalous) budding • Elongated conidiophores with long, branching chains of oval conidia • CLINICAL FEATURES • Squamous cell carcinoma LABORATORY DIAGNOSIS • • Microscopy (10-20% KOH)- muriform bodies o Diagnostic regardless of the etiologic agent Biopsy from active margins o Histopathology o Culture • • • • • • • • • • Common on exposed sites (feet, legs, arms, face, neck) → Warty papule, plaque Ulcer Pruritus, pain Large hyperkeratotic masses Scratching- satellite lesions Lymphatic spread Hematogenous spread – rare Figure 29. Muriform bodies ( they are multiple, makapal yung cell membrane, and has septa in between them. Resembles copper penny). TREATMENT • • • • • • C. Mycetoma • Maduromycosis (Madura foot) • Chronic, slowly progressive granulomatous infection of skin & subcutaneous tissue with involvement of underlying fasciae • Localized in the extremities • Common in Asia, Africa, Central & S. America soil • Eumycetoma – subcutaneous infection of fungi ( kapag it is caused by bacteria, it is called Actinomycetoma) Figure 30. Pseudolayered plaque ( nodules with sinus tracts and watery fluid inside) CLINICAL FEATURES • • • • • • Figure 28. Large hyperkeratotic masses. ( starts as plaque and it is very itchy and painful. Looks like psoriasis.) COMPLICATIONS • Secondary infection o Lymphatic stasis o Elephantiasis Itraconazole Terbinafine Itraconazole / Flucytosine / Amphotericin B Thiabendazole Cryotherapy Surgical excision - small lesions • • Foot, lower leg - common Firm, painless nodule Many nodules – lumpy appearance Multiple sinus tracts draining purulent discharge Pus discharge containing granules and grains (microcolonies) Extension to underlying bones & joints (periostitis, osteomyelitis, arthritis) Lymph node involvement- rare Triad: (MUST KNOW) o Tumefication (swelling) o Draining sinuses o Presence of granules/grains ( yung mga granules mo lalabas siya galing sa sinuses and sa granules mo din malalaman if it is 3.2 Superficial, Cutaneous, Subcutaneous Fungal Infections 9 of 11 caused by a fungi or bacteria, because usually kapag fungi kulay black or white lang siya) Figure 31. Color of granules in Mycetoma ( mukha siyang star apple) Black granules: Madurella grisea, Exophiala jeanselmei Dark red to black granules: Madurella mycetomatis White granules: Pseudallescheria boydii, Acremonium falciforme LABORATORY DIAGNOSIS • • • • • • • • Granules o Color o KOH o Gram stain o Microscopy o Culture Pus o KOH o Microscopy o Culture Eumycetoma o Wide septate hyphae with chlamydospores o Inoculate on Saboraud’s Dextrose Agar with antibiotics ELISA Immununodiffusion test Ultrasound Surgery Deep biopsy: histopathological examination TREATMENT • Eumycetoma o Amphotericin B o Grisofulvin o Ketaconazole o Excision Figure 32. Rhinosporidiosis commonly affects the nose. ( Mukha siyang naka-hang na skin tag pero warty yung itsura niya. Pwede rin makita sa mouth and perineal reagion) CLINICAL FEATURES • • • Painless itching accompanied with mucoid discharge - develops into a tumor Chronic granulomatous disease of mucous membrane Development of friable polyps in the nose, mouth or eye Figure 33. Polyp-like lesion on the eye. LABORATORY DIAGNOSIS • • • Nasal washing FNAC (Fine Needle Aspiration Cytology) Biopsy of lesion SPECIMEN IDENTIFICATION • • Presents as mold with sporangiospores Sporangia filled with thousands of sporangiospores embedded in a stroma of connective tissue and capillaries Topical nystatin or miconazole: Pseudallescheria boydii Itraconazole, ketoconazole, Amphotericin B: Madurella Flucytosine: Exophiala jeanselmei • • • • • D. Rhinosporidiosis caused by Rhinosporidium seeberi Common in India and Sri Lanka Diving and swimming in stagnant water (Seeberi for “SEA”) Commonly affects the nose May also occur in the buccal cavity, vagina, vulva, penis, urethra, rectum Figure 34. Sporangia filled with sporangiospores. TREATMENT • Dapsone ( inhibits synthesis of folic acids) 3.2 Superficial, Cutaneous, Subcutaneous Fungal Infections 10 of 11 • • Surgery ( wide excision especially if malaki na) REFERENCES Carroll, K. C., Butel, J., & Morse, S. (2015). Jawetz Melnick and Adelbergs Medical Microbiology 27 E. McGraw-Hill Education. Diving and swimming in stagnant water Rhinosporidiosis Dapsone REVIEW QUESTIONS!!! Questions Answers Trichosporon beigelli White piedra Hyphae that develops into arthroconidia (barrel shape) Piedraia hortae Black piedra Terbinafine tx Hard black nodules on shafts of scalp, beard, moustache, axillary and pubic Peidra hortae hair Malassezia furfur Spaghetti and meatballs appearance Pityriasis versicolor Ketoconazole shampoo tx Exophiala werneckii Produce melanin Branched septate hyphae and budding Tinea nigra yeast cells with melanized cell walls Saboraud’s dextrose agar Whitfield’s ointment Cutaneous mycoses “MET” Microsporum Epidermophyton Trichophyton Skin, Hair, nails Trichophyton Skin, and nails, rarely hair Epidermophton Skin and hair, rarely nails Microsporum Spindle-shaped macronidia White cottony surface and a deep red nondiffusable pigment; microconidia T. rubrum small and piriform pear shaped Flat, powdery to velvety colony; T. tonsurans micronidia elongated Thick-walled 8-15 celled macronidia M. canis Thin-walled 4-6 celled macronidia M. gypseum Club-shaped macronidia Epidermophyton floccosum Vesicle or bullae usually on the instep Tinea pedis vesiculobullous Feet Tinea pedis Head Tinea capitis Ectothrix invasion Characterized by the development of arthroconidia on the outside of the hair Ectothrix invasion shaft Characterized by the development of Endothrix hair invasion arthroconidia within the hair shaft only Anywhere in the body Ringworm Tinea corporis Margin of lesion most active, central clearing seen Groin, perineum, perianal area Annular lesion with central clearing Tinea cruris Jock itch Onychomycosis Tinea unguium Most common Tinea pedis Interdigital Chronic hyperkeratotic type Moccasin Stops fungi growth Fungistatic Rose gardener’s disease Sporothricosis Flask-shaped phialides Phialophora verucosa Muriform bodies Chromoblastomycosis Elephantiasis Madura foot Mycetoma Tumefication (swelling) 3.2 Superficial, Cutaneous, Subcutaneous Fungal Infections 11 of 11