Presentation on theme: "Fungal Infection of the Skin"— Presentation transcript:
1 Fungal Infection of the Skin Dr. Mohamad NasrLecturer Of Dermatology & Venereology
2 Topics CoveredTinea infections with special attention to scalp, feet and nailsBasic diagnostic techniquesKOHCultureWoods lightDifferentials to consider.Basic TreatmentTinea VersicolorCandidiasis
3 Dermatophytosis“Ringworm" disease of the nails, hair, and/or stratum corneum of the skin caused by fungi called dermatophytes.
4 Etiological agentsMicrosporum - 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.
5 Clinical manifestations of ringworm Infections named depending on location of infection.
6 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).
7 Tinea corporis - body ringworm Skin lesion pink-red, scaly, annular patch with expanding border (active border).
17 Tinea Capitis Treatment Must treat hair follicleTopical not effectiveSystemic agentsGriseofulvin for children ;12.5 mg/kg.Imidazoles, terbinafine.Steroids for inflamed lesions like Kerion.Treat until no visual evidence, culture (-)… plus 2 weeksAverage of 6-8 weeks of treatment.
18 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 6wkItraconazole: 5mg/kg/day,once daily or divided into two doses,for 2 to 4 weeks
19 Tinea pedis - Athletes' foot infection Between toes or toe webs - 4th and 5th toes are the most common.Types;Interdigital type.Hyperkeratotic type.Vesiculobullous type.
21 Tinea Pedis: Treatment Dry FeetAlternate shoes, Absorbent powders, Change socksScale my be reduced with keratolyticTopicals and/or Systemics.Topical: terbinafine may be more effective than azoles. Steroids if inflamed.Systemic allyamines or azoles
23 Onychomycosis 15-20% of those between 40-60 yrs. infected. No Spontaneous remissionsGeneral Appearance:Typically begins at distal nail cornerThickening and opacification of the nail plateNail bed hyperkeratosisOnycholysisDiscoloration: white, yellow, brownEdge of the nail itself becomes severely eroded.Some or all nails may be infected
34 Diagnostic Tests KOH Preparations A slide. Scrape border of lesion. Apply 1-2 drops of KOH 20% and heat gentlyExamine at 40xLook for hyphaeSpaghetti meatball appearance is classical for yeastThe most common pathogen for tinea capitus used to be microsporoum. It is now T. Tonsauran thus render wood’s light useless
36 Fungal Cultures DTM (Dermatophyte Test Medium) Sabouraud’s agar Media Yellow to red is (+).Sabouraud’s agar Media
37 Wood’s Light Tinea Capitis Other Areas: 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.
38 Tinea VersicolorNumerous, well-marginated, oval-to-round macules with a fine white scale when scraped.Pigmentary alteration uniform in each individual.RedHypo pigmentedHyperpigmentedScattered over the trunk and neck. Seldom the face.Pityrosporum orbicularis, M. furfurNormal flora of skinAsymptomatic.
48 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.
49 Tinea Versicolor-Treatment Oral; for extensiveItraconazole: 200 mg for 7daysFluconazole: 300 mg onceKetoconazole: 200 mg for 10 days
50 Tinea Versicolor-Treatment NotesHypopigmentation resolves slowlyNo scale when scraped indicates cure.Sunlight helps restore pigmentProphylaxis before summer in some patients.Selenium shampoo’s
51 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.
52 CandidiasisImmunosuppression of any type (disease, steroids, D.M. or Antibiotics).Diagnosis: History of predisposing factors and/or classic appearance of lesions at typical locations.
59 Candidiasis KOH for pseudohyphae and spores Woods Light Culture. May be impossible to tell visually from tinea.Woods LightCulture.Remember yeast part of normal flora.
60 Treatment of Candidiasis Keep dry –powder, cotton ball between toes.Topical – azoles.Systemic – fluconazole; 150 mg once.Itraconazole; 200 mg bid for 1 dayOccasionally co-administration of a weak topical steroid may be helpful.Diaper rashAngular chelitis.