fungal infection of the skin dr. mohamad nasr lecturer of dermatology & venereology
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Fungal Infection of the Skin
Dr. Mohamad Nasr Lecturer Of Dermatology & Venereology
Topics Covered
Tinea infections with special attention to scalp, feet and nails
Basic diagnostic techniques– KOH– Culture– Woods light
Differentials to consider. Basic Treatment Tinea Versicolor Candidiasis
Dermatophytosis
“Ringworm" disease of the nails, hair, and/or stratum corneum of the skin caused by fungi called dermatophytes.
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 manifestations of ringworm
Infections named depending on location of infection.
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).
Tinea corporis - body ringworm
Skin lesion pink-red, scaly, annular patch with expanding border (active border).
Tinea cruris - ringworm of the groin
Tinea capitis - ringworm of the scalp
Types:1. Scally.
2. Black dot.
3. Favus.
4. Kerion.
Scally type;
Black dot type;
Kerion;
Favus;
caused by T. schoenleinii.
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 - Athletes' foot infection
Between toes or toe webs - 4th and 5th toes are the most common.
Types;1. Interdigital type.2. Hyperkeratotic type.3. Vesiculobullous type.
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
Tinea Manuum
Onychomycosis
15-20% of those between 40-60 yrs. infected.
No Spontaneous remissions General Appearance:
– Typically begins at distal nail corner– Thickening and opacification of the nail plate– Nail bed hyperkeratosis – Onycholysis– Discoloration: white, yellow, brown– Edge of the nail itself becomes severely eroded.
Some or all nails may be infected
Tinea unguium - ringworm of the nails
Onychomycosis
Types:1. Distal Subungal
2. White superficial Chalky white patches
3. Proximal Subungal May indicate HIV infection
4. Total dystrophic
Onychomycosis
Onychomycosis with Onycholysis
White Onychomycosis
Candidaisis of nail
Paronychia
Psoriasis
Middle of nail, oils spots, pitting.
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
Tinea Faciales
Diagnostic Tests
KOH Preparations– A slide.– Scrape border of lesion.– Apply 1-2 drops of KOH 20% and heat gently– Examine at 40x– Look for hyphae
Fungal Cultures
DTM (Dermatophyte Test Medium)– Yellow to red is (+).
Sabouraud’s agar Media
Wood’s Light
– Tinea Capitis Blue green florescent with M. Canis. Not useful for Trichophyton (Most Common)
– Other Areas: Useful to diagnose as erythrasma (coral red/pink). Tinea versicolor may be pale yellow. Less helpful if patient recently bathed.
Tinea Versicolor
Numerous, well-marginated, oval-to-round macules with a fine white scale when scraped.
Pigmentary alteration uniform in each individual.
– Red– Hypo pigmented– Hyperpigmented
Scattered over the trunk and neck. Seldom the face.
Pityrosporum orbicularis, M. furfur– Normal flora of skin
Asymptomatic.
Tinea Versicolor
More apparent in the summer.
Tinea Vesicolor
Hyperpigmented
Variety
Looks Like: intertrigo, erythrasma ….
Tinea Versicolor - Differential
•Vitiligo
•Pityriasis Alba
•Pityriasis Rosea
Vitiligo
White without scale.
Pityriasis Alba
Frequently on face, KOH neg. Few lesions.
May have fine white scale.
Pityriasis Rosea
•Papules or plaques with Collarette of scale, KOH (-), Woods light neg.
Tinea Versicolor
Diagnosis:•Scrape lightly – fine white scale
•KOH Positive for short hyphae and spores (Spaghetti and meatballs)
•Woods Light – pale yellow white fluoresce.
•Culture rarely done.
Tinea Vesicolor – Woods Light
Yellow White
Tinea Versicolor Microscope
Tinea Versicolor-Treatment
Topical; for limited involvement.
•Selenium Sulfide Shampoos: lather 10 minutes wash off x 7 days.
•Ketoconazole 2% shampoo: 5 minutes 1-3 days.
•Imidazoles topicals to body qd-bid for 2-4 wks.
•Terbinafine spray.
Tinea Versicolor-Treatment
Oral; for extensive
•Itraconazole: 200 mg for 7days
•Fluconazole: 300 mg once
•Ketoconazole: 200 mg for 10 days
Notes•Hypopigmentation resolves slowly
•No scale when scraped indicates cure.
•Sunlight helps restore pigment
•Prophylaxis before summer in some patients.
•Selenium shampoo’s
Tinea Versicolor-Treatment
Candidiasis
•Candida Albicans
•Normal Flora
•Occurs in moist areas especially where skin touches.
•Presentation: primary lesion is a red pustule.
•Most Common: pustules dissect horizontally through the stratum corneum leaving a red, glistening denuded surface with long continuous border with satellite lesions.
Candidiasis
•Immunosuppression of any type (disease, steroids, D.M. or Antibiotics).
•Diagnosis: History of predisposing factors and/or classic appearance of lesions at typical locations.
Clinical picture;
1. Oral candidiasis; thrush & perleche.
2. Cutaneous candidiasis;– Intertrigo.– Erosio-interdigitalis blastomycetica.– Paronychia.
3. Genital candidiasis;
4. Systemic candidiasis;
Thrush
Angular cheilitis
Intertrigo
Intertrigo
Erosio-interdigitalis blastomycetica
Candidiasis
•KOH for pseudohyphae and spores
•May be impossible to tell visually from tinea.
•Woods Light
•Culture.
•Remember yeast part of normal flora.
Treatment of Candidiasis
• Keep dry –powder, cotton ball between toes.
• Topical – azoles.
• Systemic – fluconazole; 150 mg once.
Itraconazole; 200 mg bid for 1 day
• Occasionally co-administration of a weak topical steroid may be helpful.
• Diaper rash
• Angular chelitis.
THANK YOU
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