Presentation on theme: "1 Adult Cutaneous Fungal Infections Medical Student Core Curriculum in Dermatology Last updated May 23, 2011."— Presentation transcript:
1 Adult Cutaneous Fungal Infections Medical Student Core Curriculum in Dermatology Last updated May 23, 2011
2 Module Instructions The 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.dermatology glossary We encourage the learner to read all the hyperlinked information.
3 Goals and Objectives The 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 infections Describe the correct procedure for performing a KOH examination and interpreting the results Recognize the use and limitations of KOH examination and fungal cultures to diagnose fungal infections Recommend an initial treatment plan for an adult with tinea pedis, tinea versicolor, candidal intertrigo, and seborrheic dermatitis
4 Superficial 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). epidermis 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
5 Case One Mr. Eugene Brown
6 Case One: History HPI: 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 hospitalizations Medications: none Allergies: no known allergies Family history: noncontributory Social history: lives with wife, works as a banker Health-related behaviors: reports no alcohol, tobacco or drug use ROS: increased nocturia, otherwise negative
7 Case One: Skin Exam How would you describe these exam findings?
8 Case One: Skin Exam Erythema and scaling are present on the plantar surface and between the toes
Case One, Question 1 9 Which of the following is Mr. Browns most likely diagnosis? a.Atopic dermatitis b.Candidal intertrigo c.Onychomycosis d.Psoriasis e.Tinea pedis 9
Case One, Question 1 10 Answer: e Which of the following is Mr. Browns most likely diagnosis? a.Atopic dermatitis (Characterized by red patches and plaques ± scale. Lichenification may also result)Atopic dermatitis b.Candida intertrigo (Erythematous, eroded areas with satellite papules. Less likely location) c.Onychomycosis (Fungal infection of the nail)Onychomycosis d.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)Psoriasis e.Tinea Pedis
11 Tinea Pedis: The Basics Tinea pedis (athletes foot) is the most common fungal infection seen in developed countries, and is most commonly caused by the fungus Trichophyton rubrum Shoes provide an ideal environment for fungus to grow due to moisture Public showers, gyms, and swimming pools are common sources of infection It is difficult to permanently cure and may often recur There are three clinical patterns of infection: interdigital, moccasin, and vesiculobullous type
Most common, presents with scaling and redness between the toes and may have associated maceration.maceration 12 Tinea Pedis: Interdigital Type
Also known as chronic hyperkeratotic type. hyperkeratotic 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). 13 Tinea 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. 14 Tinea Pedis: Moccasin 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. 15 Tinea Pedis: Vesiculobullous Type
Back to Case One Eugene Brown 16
17 Case One, Question 2 Which of the following is the most appropriate next step in diagnosis? a.Begin empiric treatment with antifungals. b.KOH exam c.Skin biopsy d.Woods light
18 Case One, Question 2 Answer: b Which of the following is the most appropriate next step in diagnosis? a.Begin empiric treatment with antifungals (First need a diagnosis. There are many scaly eruptions that can occur on the foot) b.KOH exam c.Skin biopsy (This is too invasive when a simpler test is available) d.Woods light (Organisms will not fluoresce on woods light)Woods light
19 Case One: KOH Exam What are the diagnostic features in this KOH exam? Magnification 40x
20 Case One: KOH Exam What are the diagnostic features in this KOH exam? Parallel walls throughout the entire length Septated and branching hyphae Magnification 40x
21 KOH Exam: Basic Facts KOH 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 operators experience. KOH dissolves keratinocytes to allow easy viewing of hyphae. Heat is used to accelerate this reaction.
22 The KOH Exam Procedure 1.Clean and moisten skin with alcohol swab 2.Collect scale with #15 scalpel blade 3.Put scale on center of glass slide 4.Add drop of KOH and coverslip; heat slide gently with flame to adequately dissolve keratin 5.Microscopy: scan at 10X to locate hyphae; then study in detail at 40X if needed Click here to watch the videohere Make sure to turn on your computer volume (video length 8min 41sec)
23 Case One, Question 3 Which of the following are possible pitfalls of KOH prep? a.False negative KOH due to prior partial treatment with antifungals b.Misidentification of clothing fibers or lint as hyphae c.Possibility of mistaking lipid or cell membranes for hyphae d.All of the above are limitations
24 Case One, Question 3 Answer: d Which of the following are possible pitfalls of KOH prep? a.False negative KOH due to prior partial treatment with antifungals b.Misidentification of clothing fibers or lint as hyphae (clothing fibers or lint are tapered, while hyphae have parallel walls throughout) c.Possibility of mistaking lipid or cell membranes for hyphae (hyphae have parallel walls throughout and tend to be longer) d.All of the above are limitations
25 Treatment of Tinea Pedis: Hygiene For all types of tinea pedis, hygiene and topical antifungals are effective first-line therapies Hygiene: Dry the area after bathing Change socks daily and alternate shoes worn Consider wearing open shoes such as sandals Use foot powder (available over the counter) to keep feet dry
Topical Antifungals There are several classes of topical antifungal medications Some 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) 26
27 Treatment of Tinea Pedis: Topical Topical antifungals: apply until tinea shows resolution, then continue treatment for a minimum of two weeks Imidazoles: Fungistatic Examples: clotrimazole, miconazole, sulconazole, oxiconazole, ketoconazole (least activity against dermatophytes) Allylamines: Fungicidal Examples: terbinafine, butenafine, naftifine Ciclopirox: Fungicidal and fungistatic Example: Ciclopirox olamine
28 Treatment of Tinea Pedis By Type Interdigital: Topical imidazoles, ciclopirox olamine, and allylamines Plantar Moccasin/Chronic Hyperkeratotic: Topical allylamines and imidazoles Keratolytics are also useful: e.g. salicylic acid, benzoic acid (Whitfields ointment)*, urea, and lactic acid Vesiculobullous: Compresses in conjunction with antifungal agents May require an oral agent such as terbinafine or itraconazole * Whitfields ointment is a combination of salicylic and benzoic acid. In US can be bought through online pharmacies or compounded.
29 Case One, Question 5 Which of the following are common complications of tinea pedis? You may choose more than one answer. a.Deep vein thrombosis b.Furunculosis of the lower leg c.Lower leg cellulitis d.Peripheral neuropathy e.Tinea corporis
30 Case One, Question 5 Answer: c & e Which of the following are common complications of tinea pedis? a.Deep vein thrombosis b.Furunculosis of the lower leg c.Lower 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) d.Peripheral neuropathy e.Tinea corporis (from autoinoculation) 30
Onychomycosis 31 Another 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 antifungals First line treatments are oral terbinafine or itraconazole
Onychomycosis 32 Identification 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 effects Oral antifungals also have drug-drug interactions
33 Case Two Mr. Daniel Green
34 Case Two: History HPI: 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 hospitalizations Medications: none Allergies: none Family history: noncontributory Social 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.
35 Case Two: Skin Exam How would you describe these exam findings?
36 Case Two: Skin Exam This is a sharply marginated, erythematous annular lesion with central clearing and raised papulovesicular border with scaling.
37 Case Two, Question 1 Which of the following is the most appropriate next step in diagnosis? a.Biopsy b.KOH exam c.Woods light exam d.All of the above
38 Case Two, Question 1 Answer: b Which of the following is the most appropriate next step in diagnosis? a.Biopsy b.KOH exam c.Woods light exam d.All of the above
39 Case Two, Question 2 Which of the following is the most likely diagnosis? a.Atopic dermatitis b.Psoriasis c.Seborrheic dermatitis d.Tinea corporis e.Tinea cruris
40 Case Two, Question 2 Answer: d Which of the following is the most likely diagnosis? a.Atopic dermatitis (Poorly defined erythematous patches without central clearing)Atopic dermatitis b.Psoriasis (Well-demarcated erythematous plaques with silvery scale)Psoriasis c.Seborrheic dermatitis (Inflammatory reaction to yeast typically affecting face, chest, and/or scalp, often with scaling)Seborrheic dermatitis d.Tinea corporis e.Tinea cruris (Dermatophyte infection in the groin)Tinea
41 Tinea Corporis Tinea corporis, ringworm, refers to dermatophytosis of the skin, usually affecting the trunk and limbs Affects all age groups Most prominent symptom is itching Asymmetric distribution The margin of the lesion is the most active; central area tends to heal Scrapings should be taken from the red scaly margin for KOH exam A variant of this is tinea cruris or jock itch, which has a similar presentation but appears in the groin
Tinea Corporis Annular lesion with central clearing is typical of tinea corporis 42
43 Why Perform A Fungal Culture? Cultures identify the specific species of fungi causing the infection As opposed to tinea pedis, tinea corporis is caused by different fungal species with different environmental sources Animals (cats/dogs), tinea capitis, tinea pedis Using a fungal culture to identify the species will help identify the source and guide treatment Even if the KOH prep is negative, a culture may be positive
Tinea Corporis: Treatment Begin with topical treatment Topical antifungals are applied until tinea shows resolution, then continue treatment for a minimum of two weeks Imidazoles (fungistatic) Allylamines (fungicidal) Ciclopirox (fungicidal and fungistatic) Oral antifungals are indicated in the following situations: If there is a poor response to topical agents If an animal is the source of infection If eruptions involve a large surface area 44
45 Case Three Ms. Anna Jones
46 Case Three: History HPI: 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: asthma Medications: occasional multivitamin Allergies: no known drug allergies Social 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 use ROS: negative
47 Case Three: Skin Exam How would you describe these exam findings?
48 Case Three: Skin Exam Well-demarcated, pink and tan, macules and patches, across the back.
49 Case Three, Question 1 Which of the following is the most likely diagnosis? a.Pityriasis alba b.Seborrheic dermatitis c.Tinea corporis d.Tinea versicolor e.Vitiligo
50 Case Three, Question 1 Answer: d Which of the following is the most likely diagnosis? a.Pityriasis alba (noninfectious, asymptomatic poorly- defined areas of hypopigmentation; self-limited)Pityriasis alba b.Seborrheic dermatitis (abnormal immune response to normal skin yeast causing scaling and crusting)Seborrheic dermatitis c.Tinea corporis (fungal skin infection, presents as erythematous annular lesions with central clearing)Tinea corporis d.Tinea versicolor e.Vitiligo (autoimmune loss/dysfunction of melanocytes causing areas of complete depigmentation)Vitiligo
Diagnosis: Tinea Versicolor Tinea versicolor (aka Pityriasis versicolor) is not a dermatophytosis It 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 beyond Tends to recur annually in the summer months 51
Tinea Versicolor Characterized 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 distribution Visible scale is not often present, but when rubbed with a finger or scalpel blade, scale is readily seen This is a diagnostic feature of tinea versicolor Evoked scale will disappear after treatment 52
A Closer Look at Tinea Versicolor 53
54 Case Three, Question 2 Which of the following is the most appropriate next step in management? a.Fungal culture b.KOH exam c.Skin biopsy d.Woods light exam
55 Case Three, Question 2 Answer: b Which of the following is the most appropriate next step in management? a.Fungal culture (Malassezia spp. are easily identified by a KOH exam but are not easily cultured) b.KOH exam c.Skin biopsy d.Woods light exam
Microscopy The KOH exam shows short hyphae and small round spores. Characteristic spaghetti and meatball pattern. Spores (yeast forms) Short Hyphae 56
57 Microscopy with dye added to the specimen Characteristic spaghetti and meatball pattern corresponding to hyphae and spores. Magnification 40x
Tinea Versicolor: Morphology Its 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. Lets look at some examples of the various colors of tinea versicolor. 58
Tinea Versicolor: lighter 59
Tinea Versicolor: darker 60
Tinea Versicolor: pink or tan 61
62 Case Three, Question 3 Which of the following treatments would you recommend for Ms. Jones? a.Antifungal shampoo b.Ketoconazole cream c.Nystatin cream d.Oral terbinafine
63 Case Three, Question 3 Answer: a Which of the following treatments would you recommend for Ms. Jones? a.Antifungal shampoo b.Ketoconazole cream (effective for limited areas, but not widespread infections) c.Nystatin cream (not effective) d.Oral terbinafine (in contrast to topical terbinafine, oral terbinafine is not effective)
64 Case Three, Question 4 What is true about treatment of tinea versicolor? a.Normal pigmentation should return within a week of treatment b.Oral azoles should be used in most cases c.When using shampoos as body wash, leave on for ten minutes before rinsing
65 Case Three, Question 4 Answer: c What is true about treatment of tinea versicolor? a.Normal pigmentation should return within a week of treatment (usually takes weeks to months to return to normal) b.Oral azoles should be used in most cases (mild cases can be treated with topicals) c.When using shampoos as body wash, leave on for ten minutes before rinsing
Tinea Versicolor: Topical Treatment Shampoos: selenium sulfide 2% shampoo, ketoconazole shampoo, pyrithione zinc shampoo Apply daily to affected areas, lather, and rinse Spreads easily to cover larger areas Azole creams: ketoconazole, econazole, miconazole, clotrimazole Apply daily or bid for 2 weeks Can be effective for limited areas, but infections tend to be widespread, so local topical treatment associated with high relapse rate More expensive than shampoos 66
Tinea Versicolor: Oral treatment 67 Oral medication should be used when a large area is involved. Oral medications of choice include: Ketoconazole Fluconazole Itraconazole Ketoconazole 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.
Tinea Versicolor: Maintenance Therapy Many patients relapse If the patient has had more than one previous episode then recommend maintenance therapy Maintenance therapy: topicals are used 1-2x/week Ketoconazole shampoo Selenium sulfide (2.5%) lotion or shampoo Salicylic acid/sulfur bar Pyrithione zinc (bar or shampoo) Refer patients who fail maintenance therapy to dermatology 68
69 Case Four Ms. Betty Raskin
70 Case Four: History HPI: Ms. Raskin is a 62-year-old woman who presents with a red itchy rash beneath her breasts PMH: Type 2 diabetes (last hemoglobin A1c 9.2%), obesity Medications: Metformin, which she says she often does not remember to take Family history: noncontributory Social history: lives in Texas part-time Health-related behaviors: no tobacco, alcohol or drug use ROS: negative
71 Case Four, Question 1 a.Well-demarcated red plaques with overlying thick silvery scale b.Grouped vesicles on an erythematous base c.Sharply defined red plaques involving the skin folds with surrounding satellite papules d.Inflammatory nodules Which of the following best describe these characteristic exam findings?
72 Case Four, Question 1 a.Well-demarcated red plaques with overlying thick silvery scale b.Grouped vesicles on an erythematous base c.Sharply defined red plaques involving the skin folds with surrounding satellite papules d.Inflammatory nodules Answer: c Which of the following best describe these characteristic exam findings? 72
73 Case Four, Question 2 Which of the following is the most likely diagnosis? a.Atopic dermatitis b.Candidal intertrigo c.Psoriasis d.Seborrheic dermatitis e.Tinea cruris
74 Case Four, Question 2 Answer: b Which of the following is the most likely diagnosis? a.Atopic dermatitis (chronic eruption of pruritic, erythematous, oozing papules and plaques, usually with secondary lichenification and excoriation)Atopic dermatitis b.Candidal intertrigo c.Psoriasis (characterized by well-demarcated, erythematous papules and plaques with overlying silvery scale) Psoriasis d.Seborrheic dermatitis (typical skin findings range from fine white scale to erythematous patches and plaques with greasy, yellowish scale) Seborrheic dermatitis e.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)Tinea
Candidal Intertrigo: Basic Facts Candidal intertrigo = candidiasis of large skin folds May arise in the following areas: Groin or armpits Between the buttocks Under large pendulous breasts Under overhanging abdominal folds KOH exam reveals pseudohyphae Burns more than itches 75
76 Case Four, Question 3 Which of the following factors predispose to candidal intertrigo? a.Diabetes mellitus b.Hot, humid weather c.Limited mobility d.Obesity e.All of the above
77 Case Four, Question 3 Answer: e Which of the following factors predispose to candidal intertrigo? a.Diabetes mellitus b.Hot, humid weather c.Limited mobility d.Obesity e.All of the above 77
78 Case Four, Question 4 Which of the following is the most appropriate next step in management? a.Barrier creams or ointments (e.g. petroleum jelly, zinc oxide paste, etc.) b.Nystatin ointment c.Oral antifungal agent d.Oral glucocorticoid
79 Case Four, Question 4 Answer: b Which of the following is the most appropriate next step in management? a.Barrier creams or ointments (useful as adjunct/preventive therapy, but does not eradicate candida) b.Nystatin ointment (useful for candida, ointment base prevents maceration in moist areas) c.Oral antifungal agent (usually can be treated with topical agent) d.Oral glucocorticoid (may worsen the infection) 79
Candidal Intertrigo: Management Topical antifungal agents Polyenes and Imidazoles: nystatin, miconazole, clotrimazole, or econazole Allylamines are not used to treat candida Prevention Keep intertriginous areas dry, clean, and cool Encourage weight loss for obese patients Washing with benzoyl peroxide bar may reduce Candida colonization 80
Candidal Intertrigo: Management Topical anti-inflammatory Low strength glucocorticoid preparations rapidly improves the itching and burning, but should be stopped after one week Systemic antifungal agents (used for infections resistant to topical treatment) Oral fluconazole, itraconazole, or ketoconazole 81
Take 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). 82
Take Home Points Tinea 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. 83
Acknowledgements This module was developed by the American Academy of Dermatology Medical Student Core Curriculum Workgroup from Primary 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,
85 References Aly 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):
86 References Gupta AK, Kogan N, Batra R. Pityriasis versicolor: a review of pharmacological treatment options. Expert Opin Pharmacother Feb;6(2): Havlickova B, Czaika VA, Friedrich M. Epidemiological trends in skin mycoses worldwide. Mycoses Sep;51 Suppl 4:2-15. Huang DB, Ostrosky-Zeichner L, Wu JJ, Pang KR, Tyring SK. Therapy of common superficial fungal infections. Dermatol Ther. 2004;17(6): Weinberg JM, Koestenblatt EK, Tutrone WD, Tishler HR, Najarian L. Comparison of diagnostic methods in the evaluation of onychomycosis. J Am Acad Dermatol Aug;49(2): Welsh O, Vera-Cabrera L, Welsh E. Onychomycosis. Clin Dermatol Mar 4;28(2):151-9.