Presentation on theme: "Duncanville Dermatology Clinic Dermatology Residency"— Presentation transcript:
1 Fungal Infection of the Skin November 24th , 2003 Michael Hohnadel D.O. Duncanville Dermatology ClinicDermatology ResidencyKCOM Dermatology Department
2 Topics Covered Basic diagnostic techniques KOHCultureWoods lightTinea infections with special attention to scalp, feet and nailsTinea VersicolorCandidiasisDifferentials to consider.Basic Treatment
3 Questions What is a Wood’s light useful for ? If I think it might be a fungus but it is KOH negative, what can be done to prove it ?How do you know the endpoint of therapy when treating tinea capitis ?How do you know the endpoint of therapy when treating tinea versicolor ?If a patient has thick ugly nails, what is the chance that it is classic onychomycosis ?
4 Diagnostic Tests KOH Preparations Skin Two slides or slide and #15 blade.Scrape border of lesion.Apply 1-2 drops of KOH and heat gentlyExamine at 10x and 40xFocus back and forth through depth of field.Look for hyphaeClear, GreenCross cell interfacesBranch, constant diameter.Chlorazol black, Parkers ink can help.Spaghetti 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
5 Diagnostic Tests KOH Preparations Nails Hair Be Persistent ! Thin clipping, shaving or scrapingLet dissolve in KOH for 6-24 hours.Can be difficult to visualize.Culture often required.HairDirectly examined without KOH.Apply KOH and heat hair until maceratedLook for spores.Be Persistent !
17 Diagnostic Tests Wood’s Light PAS stain of skin or nail clipping. Tinea CapitisBlue 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 white yellow.Less helpful if patient recently bathed.PAS stain of skin or nail clipping.
22 Tinea Capitis Children most common cases. Most Common Organisms: T. Tonsurans - acounts for 90% in U.S.M. Canis - seen in children with infected animals.Adults not infected.M. Audouinii - grey, broken shaft tinea
23 Tinea Capitis Presentations of Tinea Capitis Non-inflammatory ‘black dot’ typeSeborrheic typePustularInflammatory (Kerion)
24 Tinea Capitis Black Dot Type Large Areas of Alopecia without inflammationMild scalingOccipital adenopathyBlack dot hairs.At first glance may look like Alopecia areata
33 Tinea Capitis - Exothrix KOH and ‘Quick Ink’M. Canis
34 Tinea Capitis Treatment Must treat hair follicleTopical not effectiveSystemic agentsGriseofulvin for children – liquid with good taste.Imidazoles, terbinafine.Steroids for inflamed lesions like Kerion.Treat until no visual evidence, culture (-)… plus 2 weeksAverage of 6-12 weeks of treatment.Examine / treat family in recurrent cases.
35 Tinea Pedis and Manuum. T. Rubrum most common etiology Dull erythema with pronounced scale.Leading edge of scale not as common.Two feet one hand involvement.T. Mentagrophytes causes inflammatory tinea pedisVesicles and bullae.
40 Tinea Pedis Groups: M > F. Young and middle aged. Patient is susceptible to reoccurrenceOnychomycosis and tinea pedis associated.Differential:Eczema, contact dermatitisPsoriasis.Erythrasma and Candida (esp in web spaces.)Pitted keratolysis
41 Tinea Pedis Diagnosis PE/History – onychomycosis, contacts, med cond. KOH exam – Thick scale, no leading edgeWoods Light - Helps to differentiate from erythrasmaCultureRemember: ‘hand eczema’ may be a dermatophyte infection of hands or id reaction from tinea at another location.
42 Tinea Pedis: Treatment Dry FeetAlternate shoes, Absorbent powders, Change socksScale my be reduced with keratolyticSAL acid, Lactic acid, CarmolTopicals and/or Systemics.Topical: naftine, lamisil, mentax may be more effective than azoles. Steroids if inflamed.Systemic allyamines or azolesTreat secondary bacterial infections.Steroids for severe inflammation and ID.
43 General Morphology Onychomycosis 15-20% of those between 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 infectedOften accompanying tinea pedis
44 Onychomycosis 4 Types: Distal Subungal White superficial T. Mentagrophytes and moldsChalky white patchesProximal SubungalMay indicate HIV infectionCandidaonychomycosisNormally hands with accompanying paronychia
59 Onychogryphosis Mostly nursing home patient with no nail care Note the concurrent tinea pedis
60 Diagnosis of Onychomycosis Try to identify fungi before oral therapyKOH of nail clippingMay need some time to dissolve nail.CultureDTM - dermatophytesSauborauds – MoldsNickerson – YeastNail clipping for histology and PAS staining if above is negative and clinical suspicion is high.
62 Treatment of Onychomycosis. Debridement of infected area helps penetration / comfort.MechanicalUrea products (ex carmol)Topical Treatment:Can be effective for limited involvement and for prevention.AgentsPenlac (every day for one year)Mycocide Nail solution
63 Treatment of Onychomycosis Oral therapyEffective. Relapse rate % in one year.Lamisil 250mg. 6 weeks/12 weeks.Baseline labs and one month.CBC (neutropenia), Liver function.Itraconazole 200 mg /day. 6 weeks/12 weeksBaseline labs and one month. Similar to lamisil.Pulse dosing fingernails - (200 mg bid 1 wk q mo.) x 2No lab monitoring needed
64 Treatment of Onychomycosis Notes on TherapyOther Azoles require longer therapy.Nails will not appear clear at end of therapyMeasurements and digital photography verify effectiveness.For you and for patient
65 General Morphology Tinea Corporis PapulosquamousErythematousAnnularScalingCrusting‘Ringworm’
68 General Morphology Tinea Versicolor Numerous, 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.
81 Tinea Versicolor-Treatment Topicals 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.
82 Tinea Versicolor-Treatment Oral for extensiveItraconazole, fluconazole, ketoconazole.Dosing varies: single dose to 5-10 days of therapy.Likes gastric ph for absorption.Avoid bathing with 12 hours of ingestion.
83 Tinea Versicolor-Treatment NotesHypopigmentation resolves slowlyNo scale when scraped indicates cure.Sunlight helps restore pigmentProphylaxis before summer in some patients.Selenium shampoo’sQ month orals
84 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.May also present as an eruption of multiple pustules which become erythematous papules between skin folds.
85 CandidiasisImmunosuppression of any type (disease, steroids), D.M., Antibiotics or receptive environments predispose.Diagnosis: History of predisposing factors and/or classic appearance of lesions at typical locations.Red and glistening in intertriginous area esp in predisposed individual think candida.
92 Treatment of Candidiasis Keep dry – Z-sorb powder, cotton ball between toes.Topical – azoles.Occasionally co-administration of a weak topical steroid may be helpful.Diaper rashAngular chelitis.Treat co-existent bacterial infection if present.