Presentation on theme: "Fungal Infection of the Skin November 24 th, 2003 Michael Hohnadel D.O. Duncanville Dermatology Clinic Dermatology Residency KCOM Dermatology Department."— Presentation transcript:
Fungal Infection of the Skin November 24 th, 2003 Michael Hohnadel D.O. Duncanville Dermatology Clinic Dermatology Residency KCOM Dermatology Department
Topics Covered Basic diagnostic techniques – KOH – Culture – Woods light Tinea infections with special attention to scalp, feet and nails Tinea Versicolor Candidiasis Differentials to consider. Basic Treatment
Questions 1.What is a Wood’s light useful for ? 2.If I think it might be a fungus but it is KOH negative, what can be done to prove it ? 3.How do you know the endpoint of therapy when treating tinea capitis ? 4.How do you know the endpoint of therapy when treating tinea versicolor ? 5.If a patient has thick ugly nails, what is the chance that it is classic onychomycosis ?
Diagnostic Tests KOH Preparations Skin – Two slides or slide and #15 blade. – Scrape border of lesion. – Apply 1-2 drops of KOH and heat gently – Examine at 10x and 40x Focus back and forth through depth of field. – Look for hyphae Clear, Green Cross cell interfaces Branch, constant diameter. – Chlorazol black, Parkers ink can help.
Diagnostic Tests KOH Preparations Nails – Thin clipping, shaving or scraping – Let dissolve in KOH for 6-24 hours. – Can be difficult to visualize. – Culture often required. Hair – Directly examined without KOH. – Apply KOH and heat hair until macerated – Look for spores. Be Persistent !
Tinea Versicolor Trichophyton Tonsurans
Parkers Ink Stain
Watch out for Mosaic Fungus
Mosaic Fungus Lipid droplets in interepithelial spaces and cell membrane overlap simulate fungal hyphae.
Diagnostic Tests Fungal Cultures DTM (Dermatophyte Test Medium) – Yellow to red is (+). Nickerson’s Media – Yeast – Black growth is (+) Sabouraud’s Media – Molds
Diagnostic Test: Fungal Culture Example of DTM
Diagostic Test Fungal Culture
Diagnostic Tests Fungal Culture Sample Collection Scrape with blade or rub with cotton Q-tip. Nail clipping or curette. Implant in media. Cap Loosely, Fungi are aerobic Read at 2 weeks and 4 weeks.
Diagnostic Tests 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 white yellow. Less helpful if patient recently bathed. PAS stain of skin or nail clipping.
Woods Light – M. Canis
Woods Light - Erythrasma
Different Types of Infection Dermatophyte Fungal Infection – Tinea Capitis – Tinea Pedis – Tinea Unguium (Onychomycosis) – Tinea Corporis – Tinea Faciales – Tinea Cruris – Tinea Manuum Tinea Vesicolor Candidiasis
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
Tinea Capitis Presentations of Tinea Capitis 1.Non-inflammatory ‘black dot’ type 2.Seborrheic type 3.Pustular 4.Inflammatory (Kerion)
Tinea Capitis Black Dot Type Large Areas of Alopecia without inflammation Mild scaling Occipital adenopathy Black dot hairs. At first glance may look like Alopecia areata
Seborrheic type Common– resembles dandruff Close exam for broken hairs, black dots Adenopathy Frequently negative KOH (70%) Culture often necessary for DX
Tinea Capitis Kerion Inflamed, Boggy and tender. M. Canis common etiology Systemic symptoms: Fever, Adenopathy. Scaring alopecia may occur KOH often negative May look bacterial
Tinea Capitis - Kerion
Tinea Capitis Pustular Discrete pustules and crusted areas No significant hair loss or scale Often KOH negative Frequently treated as bacterial at first
Tinea Capitis Diagnosis History Close contacts, pets, duration. Morphology of lesion Broken hairs, black dots, localized. Woods Lamp Blue green. Hair Shaft Exam Endo/Exothrix Culture Plucked Hair shafts, Q-tip or tooth brush.
Tinea Capitis - Endothrix
Tinea Capitis - Exothrix KOH and ‘Quick Ink’ M. Canis
Tinea Capitis Treatment Must treat hair follicle Topical not effective Systemic agents Griseofulvin for children – liquid with good taste. Imidazoles, terbinafine. Steroids for inflamed lesions like Kerion. Treat until no visual evidence, culture (-)… plus 2 weeks Average of 6-12 weeks of treatment. Examine / treat family in recurrent cases.
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 pedis Vesicles and bullae.
General Morphology Tinea Pedis
General Morphology Tinea Manuum
Two feet one hand
Tinea Pedis Groups: M > F. Young and middle aged. Patient is susceptible to reoccurrence Onychomycosis and tinea pedis associated. Differential: Eczema, contact dermatitis Psoriasis. Erythrasma and Candida (esp in web spaces.) Pitted keratolysis
Tinea Pedis Diagnosis PE/History – onychomycosis, contacts, med cond. KOH exam – Thick scale, no leading edge Woods Light - Helps to differentiate from erythrasma Culture Remember: ‘hand eczema’ may be a dermatophyte infection of hands or id reaction from tinea at another location.
Tinea Pedis: Treatment Dry Feet Alternate shoes, Absorbent powders, Change socks Scale my be reduced with keratolytic SAL acid, Lactic acid, Carmol Topicals and/or Systemics. Topical: naftine, lamisil, mentax may be more effective than azoles. Steroids if inflamed. Systemic allyamines or azoles Treat secondary bacterial infections. Steroids for severe inflammation and ID.
General Morphology Onychomycosis 15-20% of those between 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 Often accompanying tinea pedis
Onychomycosis 4 Types: 1. Distal Subungal 2. White superficial T. Mentagrophytes and molds Chalky white patches 3. Proximal Subungal May indicate HIV infection 4. Candidaonychomycosis Normally hands with accompanying paronychia
Onychomycosis with Onycholysis
Candidaisis of nail Paronychia
Onychomycosis Differential Diagnosis: (50% of ‘thick nails’ not classic fungus.) Allergic contact (nail polish, food items) Psoriasis Lichen Planus Molds Nail dystrophies (ex – nephrogenic) Drugs
Onycholysis from Contact Dermatitis to Artificial Nails
Psoriasis Middle of nail, oils spots, pitting.
Onycholysis from wet - dry
Pseudomonas of nail
Terry nails ‘half and half’
Bowen’s disease of the Nail
Diagnosis of Onychomycosis Try to identify fungi before oral therapy 1.KOH of nail clipping May need some time to dissolve nail. 2.Culture DTM - dermatophytes Sauborauds – Molds Nickerson – Yeast 3.Nail clipping for histology and PAS staining if above is negative and clinical suspicion is high.
Curettes for Specimen Collection.
Treatment of Onychomycosis. Debridement of infected area helps penetration / comfort. Mechanical Urea products (ex carmol) Topical Treatment: Can be effective for limited involvement and for prevention. Agents Penlac (every day for one year) Mycocide Nail solution
Treatment of Onychomycosis Oral therapy Effective. 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 weeks Baseline labs and one month. Similar to lamisil. Pulse dosing fingernails - (200 mg bid 1 wk q mo.) x 2 No lab monitoring needed
Treatment of Onychomycosis Notes on Therapy Other Azoles require longer therapy. Nails will not appear clear at end of therapy Measurements and digital photography verify effectiveness. For you and for patient
General Morphology Tinea Corporis Papulosquamous Erythematous Annular Scaling Crusting ‘Ringworm’
General Morphology Tinea Faciales
General Morphology Tinea Cruris
General Morphology 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.
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. HX.
Idiopathic guttate hypomelanosis White, small, no scaly, age.
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 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.
Tinea Versicolor-Treatment Oral for extensive Itraconazole, fluconazole, ketoconazole. Dosing varies: single dose to 5-10 days of therapy. Likes gastric ph for absorption. Avoid bathing with 12 hours of ingestion.
Notes Hypopigmentation resolves slowly No scale when scraped indicates cure. Sunlight helps restore pigment Prophylaxis before summer in some patients. Selenium shampoo’s Q month orals 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. May also present as an eruption of multiple pustules which become erythematous papules between skin folds.
Candidiasis Immunosuppression 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.
Difficult to be sure in Web spaces.
Candidiasis Differential: 1.Erythrasma – likes skin creases 2.Eczema – may look like pustular candida 3.Bacterial folliculitis – as above 4.Psoriasis – gluteal cleft 5.Tinea – same locations
Candidiasis KOH for pseudohyphae and spores May be impossible to tell visually from tinea. Woods Light Culture. Nickersons (+) Remember yeast part of normal flora. Add up the evidence
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 rash Angular chelitis. Treat co-existent bacterial infection if present.