Fungal Infection of the Skin Dr. Ahmed A. Kawen Dermatology & Venereology

Dermatophytosis “Ringworm" disease of the nails, hair, and/or stratum corneum of the skin caused by fungi called dermatophytes.

● Dermatophytes, have the ability to infect and survive on keratin only (skin, hair, and nail). ● They caused by three genera: Microsporum, Trichophyton, and Epidermophyton. ● Dermatopyte classified according to their origin into: Anthropophilic (human source), Zoophilic (animal source), Geophilic (soil source). Zoophilic infections usually elicit a brisk inflammatory response.  

Dermatophytosis Trichophyton Microsporum Epidermophyton T.rubrum, T.mentagrophytes, T.violaseum, T.schoenleinii, T.verrucosum Microsporum M.canis, M.gypseum Epidermophyton E.floccosum

Dermatophytosis Geophilic Zoophilic Anthropophilic M.gypseum M.canis, T.verrucosum Anthropophilic T.rubrum, T.violaseum, T.schoenleinii ,E.floccosum

Epidmiology Trichophyton rubrum is the most common dermatophyte worldwide Occur most frequently in postpubertal hosts except tinea capitis which occurs mainly in prepubertal children Men tend to more frequently have tinea cruris and tinea pedis than women

Etiological agents Microsporum - infections on skin and hair (not the cause of TINEA UNGUIUM) Epidermophyton - infections on skin and nails (not the cause of TINEA CAPITIS) Trichophyton - infections on skin, hair and nails.

Clinical Significance Click icon for audio Clinical Significance Dermatophyte Skin Hair Nails Microsporum X Trichophyton Epidermophyton The 3 main genus that we will focus on include Microsporum, Trichophyton, and Epidermophyton. From this table you can see which ones infect which body sites. An easy way to remember these is to remember that all three infect skin, Trichophyton having the prefix “tri” in its name infects all three body sites, Epidermophyton having the prefix “epiderm” focuses on skin and nails are an extension of skin. That leaves Microsporum who is the opposite of Epidermophyton and infects hair.

Clinical manifestations of ringworm Infections with dermatophytes are usually called Tinea (ringworm); for further description, the anatomical site is added, including:

Tinea capitis; ringworm infection of the scalp. Tinea corporis; ringworm infection of the body (smooth skin) Tinea cruris; ringworm infection of the groin. Tinea unguium; ringworm infection of the nails. Tinea barbae; ringworm infection of the beard. Tinea manuum; ringworm infection of the hand. Tinea pedis; ringworm infection of the foot (athlete's foot).

1- Tinea of the trunk and limbs (Tinea corporis or T. circinata): It can occur at any age. The clinical infection usually starts from an inoculation site and spreads peripherally, where the lesion becomes more pronounced (active border).

The active border: is a very characteristic pattern of dermatophyte infection, typically the active border is scaly, red, and slightly elevated, a few small vesicles and pustules may be seen within them. The lesions expand slowly and healing in the centre leaves a typical ring-like pattern, this characteristic annular appearance results from the immunological elimination of the fungus from the centre of the lesion, and the subsequent resolution of the inflammatory host response at that site.

Tinea corporis - body ringworm Skin lesion pink-red, scaly, annular patch with expanding border (active border). Any dermatophyte can cause it but the T. rubrum is the most common pathogen

Tinea imbricata T.concentricum Anthropophilic begin as small, brown, pruritic macules and papules and progress to concentric rings of scales. The infection usually begins in childhood, and progresses slowly over time. The lesions are quite pruritic, and itching aggravated by heat. . Females are more commonly affected in the adult population; this sex ratio is reversed in children . A T-cell defect caused by an autosomal recessive trait has been suggested

Tinea imbricata

Tinea imbricata

2-Tinea cruris - ringworm of the groin is common and affects men more often than women. The children are rarely affected. The upper inner thigh is involved and lesions expand slowly to form sharply demarcated plaques with active border. The scrotum is usually spared. DDX: intertrigo, contact dermatitis (irritant or allergic), candidiasis, erythrasma (bacterial infection), psoriasis, and seborrhoeic dermatitis

Caused by E. floccosum, T. rubrum and T. mentagrophytes The inflicted are more likely to have tinea pedis and onychomycosis as a source of dermatophytes

Tinea cruris - ringworm of the groin

Tinea of the groin (Tinea cruris)

3- Tinea of the face (Tinea faciei): It is limited to the glabrous skin of the face in adult males. In pediatric and female patients, the infection may appear on any surface of the face, including the upper lip and chin. The lesions have annular shape with active border

Tinea of the face (Tinea faciei)

4- Tinea of the beard (Tinea barbae): It is a superficial dermatophyte infection that is limited to the beard areas of the face and neck and occurs almost exclusively in adult males. Like tinea capitis, the hairs are infected and easily removed (easily epilation). Two types: (1) The deep type: develops slowly and produces nodules and kerion-­like swellings: acquired from animal, caused by T. mentagrophytes var. mentagrophytes and T. verrucosum.

(2)Superficial type: less inflammatory, characterized by pustular folliculitis , caused by T. rubrum. Aquired from contaminated razors in barber- shops. In both types: the hairs are either easily plucked or lost.

Tinea of the beard (Tinea barbae)

5- Tinea of the foot (Tinea pedis, Athlete’s foot):

-----Tinea pedis, It is a common type of dermatophyte infection. The forth web space is most commonly involved. A warm moist environment of the of the toe webs predispose for this infection. The involved area is usually white, macerated, and soggy, with itching. Lack of sebaceous glands and moist environment due to occlusive shoes are predisposing factors Caused by T. rubrum, T. mentagrophytes, E. floccosum

Types: (1)Moccasin: diffuse hyperkeratosis, scaling and erythema (2)Interdigital :Most common type; erythema, maceration, fissures and ,ulceration between toes (3)Inflammatory : we see vesicles and bulla

6- Tinea of the hands (Tinea manum): It appears dry diffuse and keratotic, at the palmar surface. It is different from that of back of hands due to lack of sebaceous glands on the palms Caused by T. rubrum, T. mentagrophytes and E. floccosum.

-----Tinea manum Usually non-inflammatory and often unilateral there is diffuse hyperkeratosis of the palms and digits with accentuation of scales on creases that fails to respond to emollients An important clinical clue is tinea unguium Is often present in patients with tinea pedis(two feet and one hand syndrome)

Tinea of the hands (Tinea manum)

7- Tinea of the nails (Tinea ungium, onychomycosis): The initial changes occur at the free edge of the nail, which becomes yellow and crumbly. Subungual hyperkeratosis, onycholysis, and thickening may then follow. Usually only few nails are infected but rarely all are.

infection of the nail unit Three types : based upon the point of fungal entry into the nail unit Distal/lateral subungual: with invasion via the hyponychium (most common) Superficial white: with direct penetration into the dorsal surface of the nail plate

Proximal subungual: with invasion under the proximal nail fold ( seen frequently in immunocompromised hosts). Multiple nails on one or both hands or feet are usually affected Frequently associated with chronic tinea pedis Caused by T. rubrum, T. mentagrophytes and E. floccosum

Types: Onychomycosis Distal Subungal White superficial Chalky white patches Proximal Subungal May indicate HIV infection Total dystrophic

Onychomycosis

Tinea of the nails (Tinea ungium, Onychomycosis)

Onychomycosis with Onycholysis

White Onychomycosis Leukonychia mycotica

Candidaisis of nail Paronychia

Psoriasis Middle of nail, oils spots, pitting.

Variants: Tinea incognito: tinea lesion modified by topical steroids, may lack a raised scaly border. Majocchi’s granuloma: is characterized by follicular papulopustules or nodules, commonly seen in women who have tinea pedis or onychomycosis and shave their legs. Topical steroids and immunosuppression are predisposing factors.

8- Tinea incognito (steroid modified tinea): Fungal infections treated with topical steroids, appear as diffuse erythema and scales with scattered papules and pustules, and usually lose their characteristic features (annular shape with active border).

Tinea Incognito

9-Tinea capitis - ringworm of the scalp ● Tinea capitis is a dermatophytosis of the scalp and associated hair (which lost and become easily epilated). ● It occurs mainly in children (boys more than girls),and it is very rare in adults (because fatty acids from sebaceous glands inhibit dermatophyte growth). ● Tinea capitis transmited usually by direct contact (with infected human or infected animal) or from contaminated fomites. Transmission is higher with: decreased personal hygiene, overcrowding, and low socioeconomic status. ●The most important differential diagnosis of tinea capitis is alopecia areata in which the skin is smooth without any signs of inflammation or scaling T. tonsurans is currently the most common cause of tinea capitis in the US while T.verrucosum in iraq

Types and clinical presentation: A- Noninflammatory Type (Gray Patch): It is the most common type in Iraq. Hairs in the affected area turn gray and lusterless and break off above the level of the scalp with minimal Inflammation. It is usually result from anthropophilic dermatophyte B- Inflammatory Type (Kerion): A sever inflammatory reaction with a boggy tumor like mass that exudes pus. It is usually result from zoophilic dermatophyte (cats, dogs and cattles). Inflammatory lesions are usually pruritic, and may be associated with pain, posterior cervical lymphadenopathy, and fever. If not treated properly; it is often results in scarring alopecia. C- “Black Dot” Tinea capitis: Hairs broken at the level of the scalp leave behind black dots in the areas of alopecia . D- Favus (honeycomb): Characterized by thick yellow crusts (scutula), which may lead to scarring alopecia. Types and clinical presentation:

Tinea capitis - ringworm of the scalp Types: Scally. Black dot. Favus. Kerion.

TYPES A- Noninflammatory Type (Gray Patch)

Scally type;

B- Inflammatory Type (Kerion)

Kerion;

C- “Black Dot” Tinea Capitis

Black dot type;

D- Favus

Favus; caused by T. schoenleinii.

The most important DDx of tinea capitis is Alopecia Areata

ENDOTHRIX FUNGUS

ECTOTHRIX FUNGUS 100X

TINEA CAPITIS ECTOTHRIX ENDOTHRIX YELLOW- GREEN FLUORESCENCE DULL GRAY-GREEN FLUORESCENCE M.AUDOUINII M.CANIS M.FERRUGINEUM T.SCHOENLEINII NO FLUORESCENCE M.GYPSEUM T.MENTAGROPHYTES T. RUBRUM T.TONSRANS T. VIOLACEUM

Dermatophytid “id” Reaction: A non infective cutaneous eruption (usually papulovesicular) representing an allergic response to a distinct focus of a dermatophyte infection. The condition disappears spontaneously when the primary infection is improved.  

Dermatophytid “id” reaction

Tinea Capitis Treatment Must treat hair follicle Topical not effective Systemic agents Griseofulvin for children ;12.5 mg/kg. Imidazoles, terbinafine. Steroids for inflamed lesions like Kerion. Treat until no visual evidence, culture (-)… plus 2 weeks Average of 6-8 weeks of treatment.

Other oral anti-fungal for patients who do not tolerate or respond to Griseofulvin. Terbinafine (Lamisil) 3 to 6mg/kg once a day for 2 to 4 weeks. Fluconazol: 6mg/kg/day once daily for 6wk Itraconazole: 5mg/kg/day,once daily or divided into two doses,for 2 to 4 weeks

Tinea Pedis: Treatment Dry Feet Alternate shoes, Absorbent powders, Change socks Scale my be reduced with keratolytic Topicals and/or Systemics. Topical: terbinafine may be more effective than azoles. Steroids if inflamed. Systemic allyamines or azoles

Treatment of Onychomycosis. Topical Treatment: Can be effective for limited involvement and for prevention.

Treatment of Onychomycosis Oral therapy Effective. Relapse rate 15-20 % in one year. Lamisil 250mg. 6 weeks/12 weeks. Baseline labs and one month. CBC (neutropenia), Liver function. Itraconazole. Pulse dosing fingernails - (200 mg bid 1 wk q mo.) x 2

Indication of systemic antifungal in dermatophyte infections: 1- Tinea capitis. 2- Onychomycosis. 3- Tinea incognito. 4- Widespread infection. 5- Immunocompromised patient. 6- Recurrent or persistent infection

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