Presentation on theme: "Adult Cutaneous Fungal Infections"— Presentation transcript:
1Adult Cutaneous Fungal Infections Medical Student Core Curriculumin DermatologyLast updated May 23, 2011
2Module InstructionsThe following module contains a number of blue, underlined terms which are hyperlinked to the dermatology glossary, an illustrated interactive guide to clinical dermatology and dermatopathology.We encourage the learner to read all the hyperlinked information.
3Goals and ObjectivesThe purpose of this module is to help medical students develop a clinical approach to the evaluation and initial management of patients presenting with cutaneous fungal infections.By completing this module, the learner will be able to:Identify and describe the morphologies of superficial fungal infectionsDescribe the correct procedure for performing a KOH examination and interpreting the resultsRecognize the use and limitations of KOH examination and fungal cultures to diagnose fungal infectionsRecommend an initial treatment plan for an adult with tinea pedis, tinea versicolor, candidal intertrigo, and seborrheic dermatitis
4Superficial Fungal Infections: The Basics Dermatophytoses are estimated to affect 20-25% of people worldwide, making them one of the most common infections.Superficial cutaneous fungal infections are limited to the epidermis, as opposed to systemic fungal infections (e.g. endemic mycoses and opportunistic infections).Three groups of cutaneous fungi cause superficial infections: dermatophytes, Malassezia spp., and Candida spp.Dermatophytes (which include Trichophyton spp., Microsporum spp., and Epidermophyton spp.) infect keratinized tissues: the stratum corneum (outermost epidermal layer), the nail or the hair.The term tinea is used for dermatophytoses and is modified according to the anatomic site of infection, e.g. tinea pedis
6Case One: HistoryHPI: Eugene Brown is a 62-year-old healthy man who presents to his primary care physician with a one-year history of itching and burning of his feet.PMH: no chronic illnesses or prior hospitalizationsMedications: noneAllergies: no known allergiesFamily history: noncontributorySocial history: lives with wife, works as a bankerHealth-related behaviors: reports no alcohol, tobacco or drug useROS: increased nocturia, otherwise negative
7Case One: Skin ExamHow would you describe these exam findings?
8Case One: Skin ExamErythema and scaling are present on the plantar surface and between the toes
9Case One, Question 1Which of the following is Mr. Brown’s most likely diagnosis?Atopic dermatitisCandidal intertrigoOnychomycosisPsoriasisTinea pedis9
10Case One, Question 1 Answer: e Which of the following is Mr. Brown’s most likely diagnosis?Atopic dermatitis (Characterized by red patches and plaques ± scale. Lichenification may also result)Candida intertrigo (Erythematous, eroded areas with satellite papules. Less likely location)Onychomycosis (Fungal infection of the nail)Psoriasis (The interdigital and plantar surfaces of the toes are unusual locations for psoriasis. Would expect a well- demarcated plaque with a thick silvery scale)Tinea Pedis
11Tinea Pedis: The Basics Tinea pedis (“athlete’s foot”) is the most common fungal infection seen in developed countries, and is most commonly caused by the fungus Trichophyton rubrumShoes provide an ideal environment for fungus to grow due to moisturePublic showers, gyms, and swimming pools are common sources of infectionIt is difficult to permanently cure and may often recurThere are three clinical patterns of infection: interdigital, moccasin, and vesiculobullous type
12Tinea Pedis: Interdigital Type Most common, presents with scaling and redness between the toes and may have associated maceration.
13Tinea Pedis: Moccasin Type Also known as chronic hyperkeratotic type.Sharply marginated scale, distributed along lateral borders of feet, heels, and soles.At times, vesicles and erythema are present at the margins.Often associated with onychomycosis (nail fungal infection).
14Tinea Pedis: Moccasin Type Moccasin type may present as “one hand, two feet” syndrome.Affected hand shows unilateral fine scaling, particularly in the creases (see below), and nails are often involved.
15Tinea Pedis: Vesiculobullous Type Grouped, 2-3 mm vesicles or bullae are seen, often on the arch or instep. They may be itchy or painful.Vesiculobullous type tinea pedis represents a delayed hypersensitivity immune response to a dermatophyte.
17Case One, Question 2Which of the following is the most appropriate next step in diagnosis?Begin empiric treatment with antifungals.KOH examSkin biopsyWood’s light
18Case One, Question 2 Answer: b Which of the following is the most appropriate next step in diagnosis?Begin empiric treatment with antifungals (First need a diagnosis. There are many scaly eruptions that can occur on the foot)KOH examSkin biopsy (This is too invasive when a simpler test is available)Wood’s light (Organisms will not fluoresce on wood’s light)
19What are the diagnostic features in this KOH exam? Case One: KOH ExamWhat are the diagnostic features in this KOH exam?Magnification 40x
20What are the diagnostic features in this KOH exam? Case One: KOH ExamWhat are the diagnostic features in this KOH exam?Parallel walls throughout the entire lengthSeptated and branching hyphaeMagnification 40x
21KOH Exam: Basic FactsKOH microscopy is the easiest and most cost effective method used to diagnose fungal infections of the hair, skin, and nail.Proper technique requires training.Sensitivity is dependent on the operator’s experience.KOH dissolves keratinocytes to allow easy viewing of hyphae.Heat is used to accelerate this reaction.
22The KOH Exam Procedure Clean and moisten skin with alcohol swab Collect scale with #15 scalpel bladePut scale on center of glass slideAdd drop of KOH and coverslip; heat slide gently with flame to adequately dissolve keratinMicroscopy: scan at 10X to locate hyphae; then study in detail at 40X if neededClick here to watch the videoMake sure to turn on your computer volume(video length 8min 41sec)
23Case One, Question 3Which of the following are possible pitfalls of KOH prep?False negative KOH due to prior partial treatment with antifungalsMisidentification of clothing fibers or lint as hyphaePossibility of mistaking lipid or cell membranes for hyphaeAll of the above are limitations
24Case One, Question 3 Answer: d Which of the following are possible pitfalls of KOH prep?False negative KOH due to prior partial treatment with antifungalsMisidentification of clothing fibers or lint as hyphae (clothing fibers or lint are tapered, while hyphae have parallel walls throughout)Possibility of mistaking lipid or cell membranes for hyphae (hyphae have parallel walls throughout and tend to be longer)All of the above are limitations
25Treatment of Tinea Pedis: Hygiene For all types of tinea pedis, hygiene and topical antifungals are effective first-line therapiesHygiene:Dry the area after bathingChange socks daily and alternate shoes wornConsider wearing open shoes such as sandalsUse foot powder (available over the counter) to keep feet dry
26Topical AntifungalsThere are several classes of topical antifungal medicationsSome classes are fungistatic (stop fungi from growing), others are fungicidal (they kill fungi)Not all conditions are treatable with topical antifungals (specifically, hair infections and nail infections do not respond to topical treatment and require systemic treatment)
27Treatment of Tinea Pedis: Topical Topical antifungals: apply until tinea shows resolution, then continue treatment for a minimum of two weeksImidazoles: FungistaticExamples: clotrimazole, miconazole, sulconazole, oxiconazole, ketoconazole (least activity against dermatophytes)Allylamines: FungicidalExamples: terbinafine, butenafine, naftifineCiclopirox: Fungicidal and fungistaticExample: Ciclopirox olamine
28Treatment of Tinea Pedis By Type Interdigital:Topical imidazoles, ciclopirox olamine, and allylaminesPlantar Moccasin/Chronic Hyperkeratotic:Topical allylamines and imidazolesKeratolytics are also useful: e.g. salicylic acid, benzoic acid (Whitfield’s ointment)*, urea, and lactic acidVesiculobullous:Compresses in conjunction with antifungal agentsMay require an oral agent such as terbinafine or itraconazole* Whitfield’s ointment is a combination of salicylic and benzoic acid. In US can be bought through online pharmacies or compounded.
29Case One, Question 5Which of the following are common complications of tinea pedis? You may choose more than one answer.Deep vein thrombosisFurunculosis of the lower legLower leg cellulitisPeripheral neuropathyTinea corporis
30Case One, Question 5 Answer: c & e Which of the following are common complications of tinea pedis?Deep vein thrombosisFurunculosis of the lower legLower leg cellulitis (the most common risk factor for lower leg cellulitis in immunocompetent non-diabetics is tinea pedis, which creates a portal of entry for bacteria)Peripheral neuropathyTinea corporis (from autoinoculation)30
31OnychomycosisAnother complication of tinea pedis is onychomycosis, a chronic fungal infection of the nailbed that tends to spread to other nails.Responds very poorly to topical antifungalsFirst line treatments are oral terbinafine or itraconazole
32OnychomycosisIdentification of fungus in the affected nail (at minimum a positive KOH prep or nail biopsy) is necessary before treatment, for several reasons:May mimic other conditions (e.g. psoriasis, lichen planus)Treatment is expensive, of long duration, and with potential side effectsOral antifungals also have drug-drug interactions
34Case Two: HistoryHPI: Daniel Green is a healthy 18-year-old who presents with a lesion on his right leg that has been present for 2 weeks. The lesion is itchy and is growing in size.PMH: no major illnesses or hospitalizationsMedications: noneAllergies: noneFamily history: noncontributorySocial history: Lives with his parents and sister. The family adopted a puppy 3 months ago. No history of recent travel.Health-related behaviors: no tobacco, alcohol or drug use.
35Case Two: Skin ExamHow would you describe these exam findings?
36Case Two: Skin ExamThis is a sharply marginated, erythematous annular lesion with central clearing and raised papulovesicular border with scaling.
37Case Two, Question 1Which of the following is the most appropriate next step in diagnosis?BiopsyKOH examWood’s light examAll of the above
38Case Two, Question 1 Answer: b Which of the following is the most appropriate next step in diagnosis?BiopsyKOH examWood’s light examAll of the above
39Case Two, Question 2Which of the following is the most likely diagnosis?Atopic dermatitisPsoriasisSeborrheic dermatitisTinea corporisTinea cruris
40Case Two, Question 2 Answer: d Which of the following is the most likely diagnosis?Atopic dermatitis (Poorly defined erythematous patches without central clearing)Psoriasis (Well-demarcated erythematous plaques with silvery scale)Seborrheic dermatitis (Inflammatory reaction to yeast typically affecting face, chest, and/or scalp, often with scaling)Tinea corporisTinea cruris (Dermatophyte infection in the groin)
41Tinea CorporisTinea corporis, “ringworm”, refers to dermatophytosis of the skin, usually affecting the trunk and limbsAffects all age groupsMost prominent symptom is itchingAsymmetric distributionThe margin of the lesion is the most active; central area tends to healScrapings should be taken from the red scaly margin for KOH examA variant of this is tinea cruris or “jock itch”, which has a similar presentation but appears in the groin
42Tinea CorporisAnnular lesion with central clearing is typical of tinea corporis
43Why Perform A Fungal Culture? Cultures identify the specific species of fungi causing the infectionAs opposed to tinea pedis, tinea corporis is caused by different fungal species with different environmental sourcesAnimals (cats/dogs), tinea capitis, tinea pedisUsing a fungal culture to identify the species will help identify the source and guide treatmentEven if the KOH prep is negative, a culture may be positive
44Tinea Corporis: Treatment Begin with topical treatmentTopical antifungals are applied until tinea shows resolution, then continue treatment for a minimum of two weeksImidazoles (fungistatic)Allylamines (fungicidal)Ciclopirox (fungicidal and fungistatic)Oral antifungals are indicated in the following situations:If there is a poor response to topical agentsIf an animal is the source of infectionIf eruptions involve a large surface area
46Case Three: HistoryHPI: Ms. Jones is a 27-year-old woman who presents with mild itchiness of her back which began mid summer. She is also concerned about areas on her back that do not tan.PMH: asthmaMedications: occasional multivitaminAllergies: no known drug allergiesSocial history: spends her summer months in Florida. Is an avid runner.Health-related behaviors: occasional glass of wine 1-2 times per month, no tobacco or drug useROS: negative
47Case Three: Skin ExamHow would you describe these exam findings?
48Case Three: Skin ExamWell-demarcated, pink and tan, macules and patches, across the back.
49Case Three, Question 1Which of the following is the most likely diagnosis?Pityriasis albaSeborrheic dermatitisTinea corporisTinea versicolorVitiligo
50Case Three, Question 1 Answer: d Which of the following is the most likely diagnosis?Pityriasis alba (noninfectious, asymptomatic poorly- defined areas of hypopigmentation; self-limited)Seborrheic dermatitis (abnormal immune response to normal skin yeast causing scaling and crusting)Tinea corporis (fungal skin infection, presents as erythematous annular lesions with central clearing)Tinea versicolorVitiligo (autoimmune loss/dysfunction of melanocytes causing areas of complete depigmentation)
51Diagnosis: Tinea Versicolor Tinea versicolor (aka Pityriasis versicolor) is not a dermatophytosisIt is an infection caused by species of Malassezia, a lipophilic yeast that is a normal resident in the keratin of the skin and hair follicles of individuals at puberty and beyondTends to recur annually in the summer months
52Tinea VersicolorCharacterized by well-demarcated, tan, salmon, or hypopigmented patches, occurring most commonly on the trunk (facial involvement is rare)Macules will grow, coalesce and various shapes and sizes are attained in an asymmetric distributionVisible scale is not often present, but when rubbed with a finger or scalpel blade, scale is readily seenThis is a diagnostic feature of tinea versicolorEvoked scale will disappear after treatment52
54Case Three, Question 2Which of the following is the most appropriate next step in management?Fungal cultureKOH examSkin biopsyWood’s light exam
55Case Three, Question 2 Answer: b Which of the following is the most appropriate next step in management?Fungal culture (Malassezia spp. are easily identified by a KOH exam but are not easily cultured)KOH examSkin biopsyWood’s light exam
56MicroscopySpores (yeast forms)ShortHyphaeThe KOH exam shows short hyphae and small round spores. Characteristic “spaghetti and meatball” pattern.
57Microscopy with dye added to the specimen Magnification 40xCharacteristic “spaghetti and meatball” pattern corresponding to hyphae and spores.
58Tinea Versicolor: Morphology It’s called “versicolor” because it can be light, dark, or pink to tan.In untanned Caucasians, the lesions may be salmon-colored or brown.In tanned Caucasians, the lesions may appear pale in comparison to the surrounding skin.In darker skinned individuals, lesions may appear hyper- or hypopigmented.Let’s look at some examples of the various colors of tinea versicolor.
62Case Three, Question 3Which of the following treatments would you recommend for Ms. Jones?Antifungal shampooKetoconazole creamNystatin creamOral terbinafine
63Case Three, Question 3 Answer: a Which of the following treatments would you recommend for Ms. Jones?Antifungal shampooKetoconazole cream (effective for limited areas, but not widespread infections)Nystatin cream (not effective)Oral terbinafine (in contrast to topical terbinafine, oral terbinafine is not effective)
64Case Three, Question 4What is true about treatment of tinea versicolor?Normal pigmentation should return within a week of treatmentOral azoles should be used in most casesWhen using shampoos as body wash, leave on for ten minutes before rinsing
65Case Three, Question 4 Answer: c What is true about treatment of tinea versicolor?Normal pigmentation should return within a week of treatment (usually takes weeks to months to return to normal)Oral azoles should be used in most cases (mild cases can be treated with topicals)When using shampoos as body wash, leave on for ten minutes before rinsing
66Tinea Versicolor: Topical Treatment Shampoos: selenium sulfide 2% shampoo, ketoconazole shampoo, pyrithione zinc shampooApply daily to affected areas, lather, and rinseSpreads easily to cover larger areasAzole creams: ketoconazole, econazole, miconazole, clotrimazoleApply daily or bid for 2 weeksCan be effective for limited areas, but infections tend to be widespread, so local topical treatment associated with high relapse rateMore expensive than shampoos
67Tinea Versicolor: Oral treatment Oral medication should be used when a large area is involved.Oral medications of choice include:KetoconazoleFluconazoleItraconazoleKetoconazole can be given as a one-time dose.Take on an empty stomach, exercise until perspiring (medication is delivered via sweat), and avoid shower six hours after taking medication.
68Tinea Versicolor: Maintenance Therapy Many patients relapseIf the patient has had more than one previous episode then recommend maintenance therapyMaintenance therapy: topicals are used 1-2x/weekKetoconazole shampooSelenium sulfide (2.5%) lotion or shampooSalicylic acid/sulfur barPyrithione zinc (bar or shampoo)Refer patients who fail maintenance therapy to dermatology
70Case Four: HistoryHPI: Ms. Raskin is a 62-year-old woman who presents with a red itchy rash beneath her breastsPMH: Type 2 diabetes (last hemoglobin A1c 9.2%), obesityMedications: Metformin, which she says she often does not remember to takeFamily history: noncontributorySocial history: lives in Texas part-timeHealth-related behaviors: no tobacco, alcohol or drug useROS: negative
71Case Four, Question 1Which of the following best describe these characteristic exam findings?Well-demarcated red plaques with overlying thick silvery scaleGrouped vesicles on an erythematous baseSharply defined red plaques involving the skin folds with surrounding satellite papulesInflammatory nodules
72Case Four, Question 1 Answer: c Which of the following best describe these characteristic exam findings?Well-demarcated red plaques with overlying thick silvery scaleGrouped vesicles on an erythematous baseSharply defined red plaques involving the skin folds with surrounding satellite papulesInflammatory nodules72
73Case Four, Question 2Which of the following is the most likely diagnosis?Atopic dermatitisCandidal intertrigoPsoriasisSeborrheic dermatitisTinea cruris
74Case Four, Question 2 Answer: b Which of the following is the most likely diagnosis?Atopic dermatitis (chronic eruption of pruritic, erythematous, oozing papules and plaques, usually with secondary lichenification and excoriation)Candidal intertrigoPsoriasis (characterized by well-demarcated, erythematous papules and plaques with overlying silvery scale) Seborrheic dermatitis (typical skin findings range from fine white scale to erythematous patches and plaques with greasy, yellowish scale) Tinea cruris (dermatophytosis of the groin, genitalia, pubic area, perineal, and perianal skin, usually appears as multiple erythematous papulovesicles with a well-marginated, raised border)
75Candidal Intertrigo: Basic Facts Candidal intertrigo = candidiasis of large skin foldsMay arise in the following areas:Groin or armpitsBetween the buttocksUnder large pendulous breastsUnder overhanging abdominal foldsKOH exam reveals pseudohyphaeBurns more than itches
76Case Four, Question 3Which of the following factors predispose to candidal intertrigo?Diabetes mellitusHot, humid weatherLimited mobilityObesityAll of the above
77Case Four, Question 3 Answer: e Which of the following factors predispose to candidal intertrigo?Diabetes mellitusHot, humid weatherLimited mobilityObesityAll of the above77
78Case Four, Question 4Which of the following is the most appropriate next step in management?Barrier creams or ointments (e.g. petroleum jelly, zinc oxide paste, etc.)Nystatin ointmentOral antifungal agentOral glucocorticoid
79Case Four, Question 4 Answer: b Which of the following is the most appropriate next step in management?Barrier creams or ointments (useful as adjunct/preventive therapy, but does not eradicate candida)Nystatin ointment (useful for candida, ointment base prevents maceration in moist areas)Oral antifungal agent (usually can be treated with topical agent)Oral glucocorticoid (may worsen the infection)79
80Candidal Intertrigo: Management Topical antifungal agentsPolyenes and Imidazoles: nystatin, miconazole, clotrimazole, or econazoleAllylamines are not used to treat candidaPreventionKeep intertriginous areas dry, clean, and coolEncourage weight loss for obese patientsWashing with benzoyl peroxide bar may reduce Candida colonization
81Candidal Intertrigo: Management Topical anti-inflammatoryLow strength glucocorticoid preparations rapidly improves the itching and burning, but should be stopped after one weekSystemic antifungal agents (used for infections resistant to topical treatment)Oral fluconazole, itraconazole, or ketoconazole
82Take Home Points Cutaneous fungal infections are extremely common. There are three clinical patterns of tinea pedis infection: interdigital, moccasin, and vesiculobullous type.If it scales, scrape it! KOH examination is the easiest and most cost effective method used to diagnose fungal infections of the hair, skin, and nails.Fungal culture is important because it may be positive when KOH prep is negative, and is the only easily available method to definitively identify the organism.Culture is especially helpful in tinea corporis when the source of infection is not obvious (as opposed to tinea pedis).
83Take Home PointsTinea versicolor is characterized by well-demarcated, tan, salmon, or hypopigmented patches, occurring most commonly on the trunk.Topical treatment is usually appropriate as a first-line agent for tinea pedis, tinea corporis, and candidal intertrigo, however oral medications are called for when involvement is extensive, when tinea corporis is thought to have been transmitted by an animal, and in fungal infections of the nails.Fungal infections have high rates of recurrence after treatment, but maintaining a dry, clean skin environment is helpful for prevention.Monitoring for recurrence and maintenance treatments may be helpful in patients with recurrent infection.
84AcknowledgementsThis module was developed by the American Academy of Dermatology Medical Student Core Curriculum Workgroup fromPrimary authors: Iris Ahronowitz, MD; Ronda Farah, MD; Sarah D. Cipriano, MD, MPH; Raza Aly, PhD, MPH; Timothy G. Berger, MD, FAAD.Peer reviewers: Heather Woodworth Wickless, MD, MPH; Daniel S. Loo, MD, FAAD.Revisions and editing: Sarah D. Cipriano, MD, MPH; John Trinidad. Last revised July, 2011.
85ReferencesAly R and Maibach H Atlas of Infections of the Skin. Churchill Livingstone.Berger T, Hong J, Saeed S, Colaco S, Tsang M, Kasper R. The Web-Based Illustrated Clinical Dermatology Glossary. MedEdPORTAL; Available from:De Kock CA, Sampers GH, Knottnerus JA. Diagnosis and management of cases of suspected dermatomycosis in The Netherlands: influence of general practice based potassium hydroxide testing. Br J Gen Pract Jul;45(396):Erbagci Z. Topical therapy for dermatophytoses: should corticosteroids be included? Am J Clin Dermatol. 2004;5(6):
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