University:
American Career College
Course:
NURS115 | Intermediate Medical
Academic year:

2021
Views:

211

Pages:

65
Author:

TwelveAlemat7c

Dermatophytosis Ringworm or Tinea  Some of these skin infections are known as ringworm or tinea (which is the Latin word for "worm"), though infections are not caused by worms. It is thought that the word tinea (worm) is used to describe the circular or ring form, appearance of the dermatophyte on skin. 3 Cutaneous Mycoses Dermatophytosis  Definition: The cutaneous mycoses are caused by dermatophytes (keratinophilic fungi).  Dermatophytes have 3 genera: Microsporum, Trichophyton, Epidermophyton There are about 40 species in these three genera. These species based on sexual reproduction belong to the Ascomycota phylum. 4  Colonies of dematophytes are usually restricted to the nonliving cornified layer of the epidermis. 5  Sources of dermatophytes:  Anthropophilic  Geophilic  Zoophilic 6  Keratinase, protease, elastase, lipase and phospholipase are produced by dermatophytes. 7 Clinical manifestations  Tinea capitis  Tinea corporis  Tinea pedis  Tinea mannum  Tinea cruris  Tinea unguium  Tinea barbae 8 Tinea Capitis      Tinea capitis is a dermatophyte infection of the scalp, eyebrows and eyelashes caused by species of the genera Microsporum and Trichophyton . The infections of the hairs are included three types: Ectothrix Endothrix Favus 9 Ectothrix (agents)  M. canis (the most common) is zoophilic  M. gypseum (is geophilic)  M. audoini  M. ferrogineum ( is anthropophilic) ( is anthropophilic) 10 Agents of Ectothrix  Trichophyton mentagrophytes  Trichophyton interdigitale  Trichophyton verrucosum 11 Clinical manifestations of Ectothrix  This form of tinea capitis is presented to acute and inflammatory forms.  Patches; are small and slightly erythematous, polycyclic forms and scales are branny or furfuraceous.  Infected hairs; have lost natural shine ( due to the spores on the surface the hairs) so covered with a white sheet.  Also grey patch refers to the scaling with lack of inflammation.  Kerion: is made up of dermatophytic abscesses with pus and yellow crust (characteristic sign of ectothrix). 6/15/2020 12 Scalp infection in a young child showing hair loss and a circular erythematous kerion-like lesion. Note small broken-off infected hairs. (with pus and yellow crust) M. gypseum was isolated 6/15/2020 13 Ectothrix 14 Mycological Diagnosis of Ectothrix  In macroscopic observation  The infected hairs with M. canis produce yellow-green (bright green) fluorescence under Wood's light.  Direct microscopic examination of infected hairs:  KOH 10-20% method or lactophenol mount shows; The hair shaft covered by thousands of spores (infected hairs). 15 Endothrix  The spores remain into the hair shaft  (Chronic form in girls)  Causative agents: Genus of anthropophilic source, such as Trichophyton violaceum and Trichophyton tonsurans Characteristic signs: black dots – The hairs are broken off at the scalp surface  Breakage of the hair at the follicular orifice creates patches of alopecia with black dots of broken hairs.  16 Endothrix  This type of dermatophytosis is seen in children 3 to 11 years of age.  After puberty, it may become chronic in girls 17 Black dots of Tinea capitis for endothrix infection The hairs are broken off at the scalp surface 18 Black dots of Tinea capitis for endothrix infection 19 Mycological Diagnosis of Endothrix  Direct examination of the hair by simple lacto phenol: shows, the spores within the hair. 20 Favus ( Tinea Favosa)  Favus is a disease of hair and scalp,  yellow cup-shaped crusts known as scutula were produced (characteristic sign).  Causative agent: Trichophyton schoenleini 21 Scutula 22 Mycological diagnosis In macroscopic observation  The infected hairs with Trichophyton schoenleini may show a dull-green fluorescence under Wood's light.  Direct examination: hyphae and arthroconidia can be seen within the hair. 23 Tinea corporis  Dermatophytosis of body (trunk), Ring worm and scaling lesions are seen.  Clinical manifestations: lesions are annular (ringshaped), sharply marginated, have a raised border, and may be single, or multiple. 24 Tinea corporis  Causative agents (most common): Trichophyton rubrum, T.mentagrophytes, and  Epidermophyton floccosum. 6/15/2020 25 Majocchi's granuloma A rare form of dermatophyte infection  Other more sever types of lesions are sometimes seen.  Infection of hair follicles can lead to a deep dermal inflammatory reaction.  This pustular crusted lesion is called Majocchi's granuloma .  A rare variant with deep dermal granuloma.  The organism producing this type of infection is Trichophyton rubrum. 6/15/2020 26 Dermatophyte Mycetoma  Another rare form of dermatophyte infection.  An uncommon but distinctive clinical manifestation of ringworm is invasion of the subcutaneous tissue with formation of whitish-yellowish grains of 80 to 500 µm in diameter.  6/15/2020 27 Recurrence of the disease in tinea corporis  In some patients lesions in tinea corporis repair at regular intervals.  This is caused by Trichophyton rubrum.  This species often forms ectoendoconidia in villous hair in certain patients.  Such hair acts as a reservoir for the fungus and leads to recurrence of the disease. 6/15/2020 28 Tinea corporis Scaly patches, an annular Maybe lesions with central clearing but the erythematous border were seen. 6/15/2020 29 Laboratory Identification  Direct microscopic examination of skin or nail scraping should be prepared with 10% KOH   Mycelia with septate Mycelia may fragment into arthroconidia (arthrospores) 6/15/2020 30 Tinea Unguium  Dermatophytosis of nails (toenails and fingernails).  Causative agents:  Trichophyton interdigitale, T. mentagrophytes, T. rubrum and E. floccosum  Trichophyton rubrum is important agent in tinea unguium. 6/15/2020 31      1) Distal Onychomycosis :( the most common form) 2) Lateral Onychomycosis 3) Proximal Subungual Onychomycosis (PSO) 4) White Superficial Onychomycosis (WSO) or leukonychia mycotica 5) Endonix Onychomycosis (EO) 6/15/2020 32 Eponychium 33 Distal and Lateral Onychomycosis 34 proximal subungual onychomycosis 35 White Superficial Onychomycosis White superficial onychomycosis (WSO) is a form of onychomycosis characterized by a superficial localization of fungi on the surface of 36 the nail plate. So produce whitish patches on the surface of the nail. Endonyx onychomycosis is an unusual variant of onychomycosis which involves the inner surface of nail plate without inflammation of the nail bed, onycholysis or subungual hyperkeratosis. 37 Tinea pedis  Dermatophytosis of foot, Athletʼs foot  Causative agents:  Trichophyton (T.) rubrum,  T. mentagrophytes  T. interdigitale Epidermophyton floccosum 6/15/2020 38 Tinea pedis Clinical manifestations  Chronic interdigital (the most common type)  Chronic, papulosquamous, hyperkeratotic (is very persistent and difficult to treat).  Subacute and vesicular  Acute ulcerative and pustular form of tinea pedis, rapid spread of an eczematoid vesiculopustular process is seen.  Asymptomatic (hidden form): any signs.  Just we can see dermatophytic agents by scrapping scales from interdigital (between the fingers or toes) spaces 6/15/2020 39 Tinea pedis 40 Tinea pedis 41 Tinea cruris Tinea cruris is a dermatophyte infection of the groin, perineum and perianal region, which is acute or chronic and generally severity pruritic. 6/15/2020 42 Clinical manifestations  Marginated lesions  Raised , erythematous border  Studded with numerous small vesicles  With thin, branny, furfuraceous scales  Tendency to spread to the perineum  Intergluteal areas onto buttocks  Tendency to spread to the thigh 6/15/2020 43 Tinea cruris   The disease is more common in men but frequently involves women Usually it is transmitted by intimate contact or fomite.  It may reach epidemic proportions in athletic teams, ship crews, and inmates.  It is probably most commonly transmitted by towels, linens and clothing. 6/15/2020 44 Tinea cruris  Dermatophytosis of groin  Causes: Epidermophyton floccosum (80% cases) an etiologic agent, has been isolated from blankets and sheets as well as rugs and other fomites where it can survive for years as infective arthroconidia.  Trichophyton interdigitale  T. rubrum  T. mentagrophytes 6/15/2020 45 Tinea barbae  Tinea barbae is a dermatophyte infection that is limited to the bearded areas of the face, neck and moustache occurs almost in adult males (usually seen in farmers and ranchman) is due to direct contact with an infected animal. 6/15/2020 46 Tinea barbae   Lesions are of two types: 1- A mild superficial type that resembles tinea corporis: (There is central scaling and a vesiculopustular border. The host reaction is less severe, though alopecia may develop in the center of the lesion). Trichophyton rubrum is generally the causative agent. 6/15/2020 47 Tinea barbae  2- A type in which there is a severe, deep, pustular folliculitis.  The deep or pustular type of tinea barbae is characterized by the presence of deep follicular pustules that may result in the formation of the nodular, keratinolike lesions seen in tinea capitis.  (T. verrucosum is the causative agent) 6/15/2020 48 Tinea barbae  2- A type in which there is a severe, deep, pustular folliculitis.  The deep or pustular type of tinea barbae is characterized by the presence of deep follicular pustules that may result in the formation of the nodular, keratinolike lesions seen in tinea capitis.  (T. verrucosum is the causative agent) 6/15/2020 49 Tinea barbae  The clinical presentation of tinea barbae includes inflammatory, deep, kerionlike plaques Tinea barbae  Causative agents:  T. verrucosum (originating from cattle and horses)  T. mentagrophytes (from horses and dogs) and  T. interdigitale  T. rubrum 6/15/2020 51 Tinea Manuum  Tinea manuum is a dermatophyte infection of the hand  ) between fingers, palm and usually back of the hand) 6/15/2020 52 Clinical manifestations          Hyperkeratosis Vesicular (agent: T. mentagrophytes) Erythematous scaly sheets on the dorsum Red papular and follicular patches (agent of this condition is: T. rubrum) Causes: T.rubrum T. mentagrophytes T. interdigitale Epidermophyton floccosum 6/15/2020 53 Tinea Manuum 54 Tinea Manuum 55 Tinea Manuum 6/15/2020 56 Treatment  Griseofulvin: (choice drug).  For hair and body: 3-4 weeks  For fingernails  For toenails  Terbinafine: more effective in comparison with griseofulvin especially for nail.  For topical treatment can use of azole antifungal drugs (ointment or cream). 57 Dermatophytid or id reaction (An allergic reaction to dermatophytosis )  Dermatophytid is fungus-free disseminated skin lesions resulting from induced sensitization in patients with dermatophytes infections (dermatophytosis).  The most common dermatophytid is an inflammation in the hands resulting from a fungus infection of the feet.  Also dermatophytid is an inflammation on the trunk due to tinea capitis. 6/15/2020 58 Microsporum canis macroconidia Macroconidia like spindle, with “thick echinulate wall”, 3-12 cells with excrescence on top of the macroconidia 59 Microsporum gypseum microconidia macroconidium Macroconidia like spindle, with “thin echinulate wall”, 4-6 cells 60 Trichophyton mentagrophytes microconidia macroconidium T. metagrophytes “ has both microconidia and macroconidia” Macroconidia are clavate to cigar shaped with thin, smooth wall, and with 3-6 cells 61 Trichophyton mentagrophytes 6/15/2020 62 Trichophyton rubrum T. rubrum “ has both microconidia and macroconidia” Macroconidia are thin clavate to pencil shaped with thin, smooth wall, and with 3-8 or 11 cells 63 Trichophyton schoenleinii Hyphae (Mycelia) are septate and branched without microconidia and macroconidia. Branched hyphae called "favic chandeliers“ or “antlerlike”. 6/15/2020 The tips of hyphae are swollen 64 Trichophyton schoenleinii Branched hyphae called "favic chandeliers“ or “antlerlike 65 Epidermophyton floccosum Hyphae (Mycelia) are septated and branched without microconidia and have only clavate macroconidia. Clavate Macroconidia have smooth and thin wall with 2-4 cells 6/15/2020 and Macroconidia occur singly or small clusters ( two or three on66 the same conidiophore).