[MICRO] Fungal Skin Infections.pdf

MICROBIOLOGY AND PARASITOLOGY 09/04/2024. MOD 1: FUNGAL SKIN INFECTIONS Vendale Jo...

MICROBIOLOGY AND PARASITOLOGY 09/04/2024. MOD 1: FUNGAL SKIN INFECTIONS Vendale Jon D. Figuerres, MD Trans Group/s: 8A I. SUPERFICIAL MYCOSES Fungal infections that involve the stratum corneum 1.1 Diagnosis layer of epidermis of skin Spaghetti-and-meatballs appearance COMMON SKIN DISEASES UNDER SUPERFICIAL Direct KOH (representing its spores and hyphal MYCOSES elements) 1 Pityriasis (Tinea) versicolor Wood (+) lesions appear pale yellow to white Lamp fluorescence 2 Tinea Nigra (Tinea Nigra Palmaris) (-) for usual culture media (must contain 3 Piedra Culture olive oil to promote growth since it is lipophilic) A. PITYRIASIS (TINEA) VERSICOLOR Extremely common chronic skin infection Caused by the lipophilic yeast Malassezia spp. – a normal skin commensal (or flora) ○ Most common species: M. globosa M. furfur M. sympodialis Presentation: diffuse distribution of hypopigmented macules/patches at the trunk and proximal portions of extremities Affects all ages and is not a threat of morbidity or mortality; mainly a cosmetic problem Risk factors: ○ Low immune status ○ Genetic factors ○ Elevated temperature and humidity Spaghetti-and-meatballs appearance of M. furfur in Direct Pathogenesis: overgrowth of Malassezia spp. which KOH. may be related to squamous cell turnover rate Pityriasis (Tinea) Versicolor. Wood Lamp Illumination of Pityriasis versicolor. 1. MALASSEZIA FURFUR 1.2 Treatment Common endogenous skin colonizer Selenium sulfide Overgrowth may be related to squamous cell turnover Topical or oral azoles rates ○ Lower turnover rate = higher prevalence of infection B. TINEA NIGRA (TINEA NIGRA PALMARIS) May also cause: Caused by Hortaea (Exophiala) werneckii ○ Seborrheic dermatitis (dandruff) in More prominent in warm coastal regions and young immunocompetent individuals; and women ○ Opportunistic fungemia (via total parenteral Presentation: hyperpigmented (brown to black) nutrition) in immunocompromised individuals. macules, usually on palms or soles Microbio and Para - Mod 5 Fungal Skin Infections 1 of 13 The use of trans, practice questions, and evals ratio must be used discreetly and social media/public exposure of the aforementioned shall be strictly prohibited.  ○ May be misdiagnosed as malignant melanoma as it Presentation: hard, dark brown to black gritty grows larger nodules that are firmly attached to the hair shaft When tissue biopsy is viewed under the microscope, NO ○ Nodules consists of asci containing at least eight inflammatory reaction to the infecting fungus will be ascospores seen in the tissue. Endemic in tropical countries of Africa, Asia, and Latin America Tinea Nigra. Black Piedra. 1. HORTAEA WERNECKII 2. WHITE PIEDRA (TRICHOSPORON SP.) Halotolerant fungus: can survive in environment with Caused by Trichosporon sp. relatively higher salt concentration than normal ○ Most common: (+) dematiaceous cell wall: cell wall possessing a T. ovoides melanin pigment T. asteroides T. inkin Cutaneotricosporon cutaneum ○ Some species may cause systemic mycoses in immunocompromised patients Presentation: large, soft, yellowish nodules on hair shaft Endemic in tropical areas of Africa, South America, and parts of Asia Budding yeast cells with melanized walls of H. werneckii; Colony in culture of H. werneckii (inset). 1.1 Diagnosis Branched, septate hyphae and budding Direct KOH yeast cells with melanized cell walls Shiny, moist, yeast-like colonies with an White Piedra. Culture initial brown pigmentation but eventually turn olive or greenish black DIAGNOSIS OF PIEDRA 1.2 Treatment Black Piedra (Piedraia hortae) Keratolytic solutions Salicylic acid Thick-walled rhomboid cells containing Azole antifungal drugs Direct KOH at least eight ascospores C. PIEDRA Grows slowly (approx. 2-3 weeks) on Has two forms: Sabouraud dextrose agar (SDA) at room Culture temperature 1. BLACK PIEDRA (PIEDRAIA HORTAE) Forms brown, restricted colonies that remain sterile Caused by Piedraia hortae Microbio and Para - Mod 5 🏠 Fungal Skin Infections 2 of 13 The use of trans, practice questions, and evals ratio must be used discreetly and social media/public exposure of the aforementioned shall be strictly prohibited.  White Piedra (Trichosporon sp.) Direct KOH (+) blastoconidia, arthroconidia, and (microscopical hyphal elements ly) Grow rapidly on primary fungal media (i.e., SDA, PDA) Culture Colonies appear smooth to (gross) wrinkled, straw- to cream-colored, dry to moist and yeast-like Biochemical (-) carbohydrate fermentation Tests for Use of potassium nitrate Species Assimilation of sugars Large, whitish, soft nodules of piedra attached on two hair Identification Urease positivity shafts. The hairs are subjected for culture studies. TREATMENT OF PIEDRA II. SUBCUTANEOUS MYCOSES Involves deeper layers of skin Removal of infected hair Infecting agents normally reside in soil or vegetation Application of topical agent Primary point of entry: Traumatic inoculation with contaminated material (fungal elements) ILLNESSES UNDER SUBCUTANEOUS MYCOSES 1 Sporotrichosis 2 Chromoblastomycosis 3 Phaeohyphomycosis 4 Eumycetoma A. SPOROTRICHOSIS (ROSE HANDLER’S DISEASE) Also known as “Rose Handler’s Disease” Black piedra nodule that is firmly attached on the hair shaft. Caused by a dimorphic fungus. Sporothrix schenckii The darker area is the ascospores; fungal ascus is the whole Acquired through direct contact with plants such as thing that embraces the hair shaft. sphagnum moss, rose thorns, decaying wood, pine straw, and prairie grass 75% occur in males due to increased exposure or X-linked difference in susceptibility Occupational disease: common among forest rangers and horticulturist Presentation/lesion: appear as erythematous, painless nodules which may eventually ulcerate Lymphocutaneous sporotrichosis ○ About 75% of the cases ○ Wherein a series of granulomatous nodules initially develop within the lymphatic tract ○ Eventually become necrotic/ulcerative lesions Fixed sporotrichosis ○ Single non-lymphangitic nodule ○ Limited to cutaneous tissue ○ Less progressive Brown restricted colonies of Piedraia hortae in an SDA ○ More common in endemic areas such as Mexico medium. Rarely become systemic disease (i.e. primary pulmonary sporotrichosis) ○ Immunocompromised patients may develop systemic sporotrichosis Direct KOH of Trichosporon sp. Hyphal elements, arthroconidia, and blastoconidia. Microbio and Para - Mod 5 🏠 Fungal Skin Infections 3 of 13 The use of trans, practice questions, and evals ratio must be used discreetly and social media/public exposure of the aforementioned shall be strictly prohibited.  Sporothrix schenckii mold. Lymphocutaneous Sporotrichosis. 1.1 Diagnosis Biopsy material (e.g., tissue) Specimens Exudate from granulomatous or ulcerative lesion Direct KOH Yeasts are rarely seen Gomori Methenamine Silver Stain: dyes the fungal cell wall black Periodic Acid Schiff Stain: dyes the Special fungal cell wall red Stains ○ Asteroid body: central basophilic (histologic yeast cell surrounded by radiating studies) extensions of eosinophilic material (which are deposits of Fixed Sporotrichosis. antigen-antibody complexes and complement system) 1. SPOROTHRIX SCHENCKII Most reliable diagnostic method to Commonly recovered from soil and decaying definitively diagnose sporotrichosis vegetation Cultured in Sabouraud Dextrose Agar Distributed in warm, arid areas (i.e. Mexico), moist, (SDA) and Brain Heart Infusion (BHI) humid regions (i.e. Brazil, South Africa, Uruguay), and Culture Agar with sheep blood (to temperate regions (i.e. USA, France, Canada). demonstrate thermal dimorphism) ○ Most cases in temperate regions are associated Young colonies: blackish and shiny with gardening Old colonies: wrinkled and fuzzy Morphological features: ○ Thermally dimorphic Serology Generally not useful ○ Yeast (At 35 - 37 °C): small, cigar-shaped ○ Mold (At 25°C): thin, delicate, septate hyphae bearing conidia developing in a rosette pattern at the ends of delicate conidiophores; may present with dematiaceous cell wall Asteroid Bodies. 1.2 Treatment Usually self-limited Drug of Choice (DOC): ○ Oral Itraconazole for subcutaneous mycoses ○ Amphotericin B for systemic disease 1.3 Prevention and Control Sporothrix schenckii yeast. Wearing of gloves when gardening Use of fungicides to treat wood Microbio and Para - Mod 5 🏠 Fungal Skin Infections 4 of 13 The use of trans, practice questions, and evals ratio must be used discreetly and social media/public exposure of the aforementioned shall be strictly prohibited. B. CHROMOBLASTOMYCOSIS Chronic subcutaneous infection Most common in tropical and subtropical regions Acquired through direct inoculation via trauma Does NOT generally involve the muscle or bone Main site of infection: lower extremities ○ Less common sites: hands and back Lesion: localized, wart-like, scaly lesions with small ulcerations of haemopurulent material on the warty surface; ○ Chronic lesion: cauliflower-like nodules with crusting abscesses May rarely produce elephantiasis due to lymphatic obstruction and fibrosis Fonsecaea pedrosoi. Dissemination to other parts of the body is very rare NOT COMMUNICABLE 1.3 Fonsecaea compactum Small, almost spherical blastoconidia, with a broad base connecting the conidia Smaller and more compact than F. pedrosoi Chromoblastomycosis. 1. INFECTING AGENTS Dematiaceous, saprophytic fungal organisms which contain melanin in their cell walls All have dematiaceous cell walls Reside in soil and vegetation Fonsecaea compactum. Identified based on the morphology of their conidia and conidiophore 1.4 Rhinocladiella aquaspersa Produces lateral or terminal conidia from a 1 Phialophora verrucosa lengthening conidiogenous cell Conidia are elliptical to clavate 2 Fonsecaea pedrosoi 3 Fonsecaea compactum 4 Rhinocladiella aquaspersa 5 Cladophialophora carrionii 1.1 Phialophora verrucosa Conidia are produced from flask-shaped conidiophores (called phialides) with cup-shaped collarettes carrying the blastoconidia Rhinocladiella aquaspersa. 1.5 Cladophialophora carrionii Produces elongated chains of conidiophores with long, branching chains of oval conidia Phialophora verrucosa. 1.2 Fonsecaea pedrosoi Short branching chains of blastoconidia as well as sympodial conidia Microbio and Para - Mod 5 🏠 Fungal Skin Infections 5 of 13 The use of trans, practice questions, and evals ratio must be used discreetly and social media/public exposure of the aforementioned shall be strictly prohibited.  DOC: oral therapy of flucytosine or itraconazole for larger lesions Heat is also beneficial 4. PREVENTION AND CONTROL Wearing of shoes and protecting the legs when working on soil C. PHAEOHYPHOMYCOSIS Majority of the agents in this disease contain melanin in their cell walls (dematiaceous cell walls) Caused by the following exogenous molds (saprophytic fungal organisms) which are found in soil, plants and decaying organic matter: Cladophialophora carrionii. ○ Exophiala jeanselmei ○ Phialophora richardsiae 2. DIAGNOSIS ○ Bipolaris spicifera ○ Wangiella dermatitidis Specimens Lesion scrapings ○ Exserohilum rostratum Tissue biopsies ○ Alternaria sp. ○ Curvularia sp. Direct KOH (+) dark, spherical cells Cutaneous Lesion: starts as an erythematous nodule at a site of minor trauma; typically enlarges and may Histologic Granuloma with sclerotic bodies within involve deep tissues, including bone Study leukocytes or giant cells Immunocompromised patients are at highest risk Can disseminate to other parts of the body, including the Culture SDA with antibiotics or Inhibitory Mold brain Agar (IMA) ○ Most common cause of cerebral Unable to grow at 37 C phaeohyphomycosis: Cladophialophora bantiana Colonies appear velvety to woolly and gray-brown to olivaceous black Wet mount preparations may exhibit dematiaceous cell wall Digests gelatin Subcutaneous and Cerebral Phaeohyphomycosis. 1. DIAGNOSIS Histologic Large, septate, branched or Studies unbranched, often swollen or toruloid (beaded) hyphae that may be Chromoblastomycosis granuloma. accompanied by yeast cells, either occurring singly or in short chains; (+) melanin in cell walls (dematiaceous) via Fontana-Masson method Culture Yeast-like, olivaceous to colonies that eventually becomes velvety Non-specific; cannot easily distinguish specific causative agent Sclerotic bodies. 3. TREATMENT Surgical excision with wide margins for small lesions Microbio and Para - Mod 5 🏠 Fungal Skin Infections 6 of 13 The use of trans, practice questions, and evals ratio must be used discreetly and social media/public exposure of the aforementioned shall be strictly prohibited.  Eumycetoma. 1.1 Madurella mycetomatis Dematiaceous, septate fungi Produce conidia from the tips of phialides, but may Phaeohyphomycosis lesion in a histologic study. remain sterile 2. TREATMENT 2. DIAGNOSIS DOC: Fungal culture using Sabouraud Dextrose Agar (SDA) ○ Itraconazole and flucytosine for subcutaneous with antibiotics may be done to confirm diagnosis. phaeohyphomycosis ○ Amphotericin B and surgery for cerebral or Specimen Draining exudate (often superinfected with systemic phaeohyphomycosis staphylococci or streptococci) Surgical debridement (of lesions) is necessary for cure Histo- Histologic findings of granules surrounded pathologic by abscess and necrotic debris from a D. MYCETOMA Studies draining exudate; granule color may provide Chronic subcutaneous infections that may be caused by the identity of etiologic agent: actinomycetes or fungi P. boydii and A. falciforme: produce ○ Actinomycetoma: infections caused by white granule actinomycetes M. grisea and E. jeanselmei: black ○ Eumycetoma: infections caused by fungi granule M. mycetomatis: dark red to black granule FUNGAL AGENTS OF EUMYCETOMA Culture SDA with antibiotics 1 Pseudallescheria boydii (to confirm Eumycetoma organisms grows very 2 Madurella mycetomatis diagnosis) slowly and initially produces white colonies that become yellow, 3 Madurella grisea olivaceous or brown, with a characteristic of diffusible brown 4 Exophalia jeanselmei pigment with age Grows best at 37°C, with slower growth 5 Acremonium falciforme at 40°C Madurella sp. and Exophiala jeanselmei are dematiaceous organisms or organisms that have melanin in their cell walls. 1. EUMYCETOMA “Maduromycosis” or “Madura foot” Majority of cases are caused by Madurella mycetomatis Occurs worldwide, but is prevalent in India, Africa, and Latin America Subcutaneous mycosis that develops after traumatic M. mycetomatis colony. inoculation with contaminated soil or vegetation Common sites: subcutaneous tissues of feet, lower extremities, and hands Lesion: swelling with suppurative exudates containing granules draining at the skin surface (of feet, lower extremities, or hands) through sinus tracts May affect and spread to contiguous muscle and bone Microbio and Para - Mod 5 🏠 Fungal Skin Infections 7 of 13 The use of trans, practice questions, and evals ratio must be used discreetly and social media/public exposure of the aforementioned shall be strictly prohibited.  b Piedraia hortae c Hortaea werneckii d Trichosporon ovoides Which of the following structures is a characteristic of the etiologic agent? a Sac-like structures b Sporangium c Club-shaped structures d Sterigma Eumycetoma granules (reddish brown). 2 A 58-year-old gardener came into your clinic due The granules produced are dark red, thus, it can be to a lesion on his right arm. Upon physical inferred that the causative agent for this case is examination, you observed an ovoid, Madurella mycetomatis. erythematous nodule with central ulceration. No tenderness noted upon palpating the lesion. Scrapings from the lesion was collected and was submitted to the laboratory for further studies. Direct KOH shows fungal elements. Which of the following statements is true regarding the disease entity of the case? a It is acquired via direct contact with an infected animal/human. b There is lymphatic involvement in this case c It is usually self-limited d Cases of this disease in tropical regions usually involves gardening Eumycetoma granules (black). Which of the following characteristics is observed in KOH? The granules produced are black, hence, it can be inferred that this lesion is caused by either of the ff. a Thin, delicate, septate hyphae bearing conidia organisms: developing in a rosette pattern at the ends of delicate Madurella grisea conidiophores Madurella mycetomatis Exophiala jeanselmei b Elongated conidiophores with long, branching chains of oval conidia 3. TREATMENT c Septate, branched or unbranched, often swollen or toruloid (beaded) hyphae that may be accompanied Antibiotic treatment depends on the causative agent by yeast cells DOC: ○ P. boydii: topical Nystatin or Miconazole d Short branching chains of blastoconidia as well as ○ Madurella sp.: Itraconazole, Ketoconazole, sympodial conidia Amphotericin B ○ E. jeanselmei: Flucytosine I. CUTANEOUS MYCOSES (DERMATOPHYTOSES) 4. PREVENTION AND CONTROL Fungal infections that infect the keratinized tissues (i.e. hair, nail, skin) Wearing of shoes when walking on soil Most important causative agents: dermatophytes Proper wound cleaning Restricted to skin because most dermatophytes are unable to grow at 37℃ or in the presence of serum III. PRACTICE CASES Acquired by direct contact with contaminated soil, with infected animals or humans, or via fomites 1 A 7-year-old female was brought to your clinic due to scalp itchiness. Upon physical DERMATOPHYTES examination, you noticed multiple hard, black gritty nodules on the hair shafts 3 fungal agents that cause dermatophytosis: What is the etiologic agent of this case? 1 Tricophyton sp. a Malassezia globose 2 Microsporum sp. Microbio and Para - Mod 5 🏠 Fungal Skin Infections 8 of 13 The use of trans, practice questions, and evals ratio must be used discreetly and social media/public exposure of the aforementioned shall be strictly prohibited.  3 Epidermophyton sp. Microconidia Primarily globose but may appear tear-shaped; occur in grape-like clusters A. DERMATOPHYTES Species lose the ability to reproduce sexually and to Macroconidia Thin-walled, smooth and produce asexual conidia when their habitation evolve cigar-shaped, with four to five cells from soil to animal or human separated by parallel cross-walls Anthropophilic dermatophytes cause chronic and mild infections; difficult to eradicate Culture Granular colonies if abundant Zoophilic and geophilic dermatophytes produce acute microconidia inflammatory infections that tend to resolve quickly Smooth if less microconidia Rapid growing in Sabouraud Dextrose Agar (SDA) and Potato DERMATOPHYTE CLASSIFICATIONS Dextrose Agar (PDA) Usual Class Species 1.2 Trichophyton rubrum Habitat Epidermophyton floccosum Trichophyton mentagrophytes Anthropo- Humans var. interdigitale philic Trichophyton rubrum Trichophyton tonsurans Microsporum canis (dogs and cats) Microsporum gallinae (fowls) Zoophilic Animals Microsporum nanum (pigs) Trichophyton rubrum. Trichophyton equinum (horses) Microconidia Clavate- or peg-shaped formed along Trichophyton verrucosum (cattle) undifferentiated hyphae Geophilic Soil Microsporum gypseum Macroconidia Three- to eight-cell; cylindrical in shape Culture Initially produces white colonies Species identification is dependent on morphology of (in SDA and but may eventually turn into yellow asexual conidia. PDA) or red; Host susceptibility for infection may be enhanced by Most strains develop red to deep moisture, warmth, skin chemistry, sebum and burgundy wine-colored pigment perspiration content, youth, heavy exposure and genetic on the reverse side of the agar plate factors. Incidence is higher in hot, humid climates and in overcrowded areas. 1.3 Trichophyton tonsurans HIGHLY CONTAGIOUS, but rarely become systemic illness ○ High risk: immunocompromised patients 1. TRICHOPHYTON SP. 1.1 Trichophyton mentagrophytes Trichophyton tonsurans. Microconidia Variable shape (round to peg-shaped or elongated); formed along the hyphae or on short conidiophores Macroconidia Rare incidence; variable shape Trichophyton mentagrophytes. (cylindrical to cigar-shaped) Culture Flat, powdery to velvety colonies Microbio and Para - Mod 5 🏠 Fungal Skin Infections 9 of 13 The use of trans, practice questions, and evals ratio must be used discreetly and social media/public exposure of the aforementioned shall be strictly prohibited.  Reddish brown (rust-colored) on May have brown to red pigment reverse side of agar plate on the reverse side of agar plate 2. MICROSPORUM SP. 3. EPIDERMOPHYTON SP. Two species are clinically important: 3.1 Epidermophyton floccosum 2.1 Microsporum canis (zoophilic) Only medically important species belonging to the genus Epidermophyton Only produces macroconidia Macroconidia 2 to 5-celled, smooth, thin walled occurring singly or in clusters; Key feature: broad or spatulate distal end (resemble beaver’s tail) Culture Small, flat, yellow to yellow-tan colonies with feathered edges Microsporum canis. Microconidia Resembles microconidia of other dermatophytes; not useful for diagnosis Macroconidia 8 to 15-celled, spindle-shaped, echinulate, thick-walled; Key features: tapering/elongated, spiny distal ends Epidermophyton floccosum. Culture Fluffy and cream white colonies II. DISEASES CAUSED BY DERMATOPHYTES (in PDA) Deep lemon yellow pigment on Nomenclature is based on the location of infection. reverse side of agar plate 1 Tinea Capitis (infects head or scalp) 2.2 Microsporum gypseum (geophilic) 2 Tinea Unguium (Onychomycosis) 3 Tinea Pedis (Athlete’s Foot) 4 Tinea (Corporis, Curis, Manuum) 5 Tinea Barbae 6 Dermatophytid (allergic reaction to fungal elements and product) 7 Systemic Illness (rarely) A. TINEA CAPITIS Dermatophytosis involving the skin of the scalp which originates from the hair follicles Microsporum gypseum. 1. TINEA FAVUS Microconidia Resembles microconidia of other Subtype of Tinea Capitis dermatophytes; not useful for Acute inflammatory infection of hair follicle caused diagnosis by Trichophyton schoenleinii ○ Hyphal elements can be found within the hair shaft Macroconidia 4 to 6-celled, fusiform, thin-to Progresses to a crusty lesion made up of dead epithelial moderately thick-walled; distal end cells and fungal mycelia (scutula) may have thin, filamentous tail ○ Results in hair loss and scar tissue formation Culture Powdery and granular colonies (if abundant microconidia and macroconidia) Microbio and Para - Mod 5 🏠 Fungal Skin Infections 10 of 13 The use of trans, practice questions, and evals ratio must be used discreetly and social media/public exposure of the aforementioned shall be strictly prohibited.  B. TINEA BARBAE (BARBER’S ITCH) Cutaneous mycosis usually caused by a zoophilic dermatophyte Involves the bearded regions Lesions may resemble pyogenic infection Tinea favus. 2. TWO DISTINCT FORMS OF TINEA CAPITIS Tinea Barbae. 2.1 Gray Patch Ringworm Common childhood disease C. TINEA PEDIS (ATHLETE’S FOOT) Caused by Microsporum sp. MOST PREVALENT dermatophyte ○ Colonizes the outer portion of hair shaft Arises from infected skin scales coming into contact (ectothrix) by producing a chain of spores that form with exposed skin via formites a sheath around it Commonly affected areas: soles and toe webs Seldom inflamed, but luster (lustration) and color of May produce extensive fissure, scaling, and the hair shaft may be lost erythema (Moccasin Foot) when it becomes chronic Wood’s Lamp: sheaths produce (+) greenish to silvery May promote secondary bacterial infections fluorescence Tinea Pedis. D. TINEA UNGUIUM (ONYCHOMYCOSIS) Caused by dermatophytes originating from tinea pedis or tinea manuum Gray Patch Ringworm on Scalp and Wood Lamp. Most common infecting agents (all anthropophilic): ○ T. mentagophyte 2.2 Black Dot Ringworm ○ T. rubum Involves the inner portion of the hair shaft (endothrix) ○ T. tonsurans Caused by Trichophyton tonsurans ○ E. floccosum ○ Produces spores at the hair follicle which eventually Infected nails become disfigured and may have extends towards the endothrix of the hair shaft whitish plaques on the nail bed or nail plate Results to weakened hair that breaks easily at the Most common form: Subungual form follicular opening, thereby leaving “black dot stubs” Difficult to treat ○ Long term therapy of Terbinafine or Itraconazole is recommended ○ Ungiectomy: plays a huge role in limiting and possibly eradicating the infection. However, recurrence is highly possible. Black Dot Ringworm. Microbio and Para - Mod 5 🏠 Fungal Skin Infections 11 of 13 The use of trans, practice questions, and evals ratio must be used discreetly and social media/public exposure of the aforementioned shall be strictly prohibited.  Appear as pruritic, vesicular to bullous lesions on hands or any parts of the body distant to the infected site. Skin test: markedly (+) Trichophytin Important: Lesions DO NOT contain the fungal agent responsible for the infection. May become secondarily infected with bacteria. Tinea Unguium. E. TINEA CRURIS, CORPORIS AND MANUUM “Ringworm” for tinea corporis and tinea manuum ○ Infection occurs in the torso (corporis) and hands/fingers (manuum) area. “Jock’s Itch” for tinea cruris — infection occurs in the groin area Lesion: annular with clearing, scaly center surrounded Dermatophytids. by a red advancing border that may be dry or vesicular Infection expands centrifugally and active hyphal III. DIAGNOSTICS growth occurs at the periphery. The erythema, vesicle formation, and pruritus are caused by fungal metabolites, enzymes, and antigens. Specimens Keratinized tissue samples such as: Zoopholic and geophilic dermatophytes produce Skin scrapings more irritants and inflammation. Hair Nail clippings May be submitted to the laboratory for Direct KOH testing to confirm the diagnosis. Direct KOH Under the microscope: The morphology of asexual conidia is the main species identifier for dermatophytes. Branching hyphal elements or chains of arthroconidia may be seen. Tinea Manuum. Culture SDA with antibiotics (commonly used medium for dermatophyte growth); colonial morphology may be helpful, but not very specific Wood (+) fluorescence for Microsporum sp. Lamp spores from hair shaft IV. TREATMENT, PREVENTION AND CONTROL A. TREATMENT Removal of infected hair and dead epithelial Tinea Corporis. structures Application of topical antifungal drug DOC — dependent on the location of infection ○ Oral Griseofulvin or Terbinafine for tinea capitis ○ Itraconazole and Terbinafine for tinea corporis, tinea pedis, tinea cruris, tinea manuum B. PREVENTION AND CONTROL Keep high-risk areas (i.e. hands, feet, inguinal area, underarms) dry Avoid sharing of possible fomites (i.e. shoes, socks, towels) Tinea Cruris. V. PRACTICE CASES F. DERMATOPHYTIDS 1 A 14-year-old male came into your clinic due to Hypersensitivity reaction to constituents or products of the pruritus of his feet. The patient is a member the dermatophytes of basketball league in his school and often Microbio and Para - Mod 5 🏠 Fungal Skin Infections 12 of 13 The use of trans, practice questions, and evals ratio must be used discreetly and social media/public exposure of the aforementioned shall be strictly prohibited.  forgets to dry his feet after showering. Upon physical examination, you noticed erythema with scaling on soles and foot webs. Which of the following would most likely be a concomitant infection? a Tinea favus b Tinea capitis c Dermatophytid d Tinea unguium The following statements are true regarding the disease, EXCEPT: a Chronicity of infection may result into extensive fissure, scaling, and erythema b Itraconazole is one of the drugs of choice c Production of vesicular lesions at a distal site may occur d It is one of the least prevalent dermatophytosis Microbio and Para - Mod 5 🏠 Fungal Skin Infections 13 of 13 The use of trans, practice questions, and evals ratio must be used discreetly and social media/public exposure of the aforementioned shall be strictly prohibited.