1. Fungal Infection of the Skin November 24th , 2003 Michael Hohnadel D.O.
Duncanville Dermatology Clinic
Dermatology Residency
KCOM Dermatology Department

2. 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

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 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.
Spaghetti meatball appearance is classical for yeast
The 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 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 !

6. Tinea Versicolor
Trichophyton
Tonsurans

7. Tinea Versicolor

8. Parkers Ink Stain

9. Watch out for Mosaic Fungus

10. Mosaic Fungus
Lipid droplets in interepithelial spaces and cell membrane overlap simulate fungal hyphae.

11. Fungal Cultures Diagnostic Tests DTM (Dermatophyte Test Medium)
Yellow to red is (+).
Nickerson’s Media
Yeast
Black growth is (+)
Sabouraud’s Media
Molds

12. Diagnostic Test: Fungal Culture Example of DTM

13. Diagostic Test Fungal Culture

14. 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.

16. Tinea Capitis

17. Diagnostic Tests Wood’s Light PAS stain of skin or nail clipping.
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.

18. Woods Light – M. Canis

19. Woods Light - Erythrasma

20. 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

21. Tinea Capitis

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’ type
Seborrheic type
Pustular
Inflammatory (Kerion)

24. 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

25. Tinea Capitis

26. Tinea Capitis Seborrheic type Common– resembles dandruff
Close exam for broken hairs, black dots
Adenopathy
Frequently negative KOH (70%)
Culture often necessary for DX

27. 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

28. Tinea Capitis - Kerion

29. Tinea Capitis Pustular Discrete pustules and crusted areas
No significant hair loss or scale
Often KOH negative
Frequently treated as bacterial at first

30. 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.

31. Normal Hair

32. Tinea Capitis - Endothrix

33. Tinea Capitis - Exothrix
KOH and ‘Quick Ink’
M. Canis

34. 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.

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 pedis
Vesicles and bullae.

36. General Morphology Tinea Pedis

37. Tinea Pedis

38. General Morphology Tinea Manuum

39. Two feet one hand

40. 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

41. 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.

42. 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.

43. 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

44. Onychomycosis 4 Types: Distal Subungal White superficial
T. Mentagrophytes and molds
Chalky white patches
Proximal Subungal
May indicate HIV infection
Candidaonychomycosis
Normally hands with accompanying paronychia

45. Onychomycosis

46. Onychomycosis with Onycholysis

47. White Onychomycosis

48. Candidaisis of nail
Paronychia

49. Onychomycosis Allergic contact (nail polish, food items) Psoriasis
Differential Diagnosis: (50% of ‘thick nails’ not classic fungus.)
Allergic contact (nail polish, food items)
Psoriasis
Lichen Planus
Molds
Nail dystrophies (ex – nephrogenic)
Drugs

50. Onycholysis from Contact Dermatitis to Artificial Nails

51. Psoriasis
Middle of nail, oils spots, pitting.

52. Psoriasis

53. Lichen Planus

54. Onycholysis from wet - dry

55. Pseudomonas of nail

56. Terry nails ‘half and half’

57. Molds

58. Bowen’s disease of the Nail

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 therapy
KOH of nail clipping
May need some time to dissolve nail.
Culture
DTM - dermatophytes
Sauborauds – Molds
Nickerson – Yeast
Nail clipping for histology and PAS staining if above is negative and clinical suspicion is high.

61. Curettes for Specimen Collection.

62. 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

63. 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

64. 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

65. General Morphology Tinea Corporis
Papulosquamous
Erythematous
Annular
Scaling
Crusting
‘Ringworm’

66. General Morphology Tinea Faciales

67. General Morphology Tinea Cruris

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.
Red
Hypo pigmented
Hyperpigmented
Scattered over the trunk and neck. Seldom the face.
Pityrosporum orbicularis, M. furfur
Normal flora of skin
Asymptomatic.

69. Tinea Versicolor
More apparent in the summer.

70. Tinea Vesicolor Hyperpigmented Variety
Looks Like: intertrigo, erythrasma ….

71. Tinea Versicolor - Differential
Vitiligo
Pityriasis Alba
Pityriasis Rosea
Nummular Eczema
Psoriasis
Idiopathic guttate hypomelanosis

72. Vitiligo
White without scale.

73. Pityriasis Alba Frequently on face, KOH neg. Few lesions.
May have fine white scale.

74. Pityriasis Rosea
Papules or plaques with Collarette of scale, KOH (-), Woods light neg. HX.

75. Guttate Psoriasis

76. Idiopathic guttate hypomelanosis
White, small, no scaly, age.

77. 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.

78. Tinea Versicolor

79. Tinea Vesicolor – Woods Light
Yellow White

80. Tinea Versicolor Microscope

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 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.

83. Tinea Versicolor-Treatment
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

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. 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.

86. Candidiasis

87. Candidiasis

88. Difficult to be sure in Web spaces.

89. Candidiasis Differential: Erythrasma – likes skin creases
Eczema – may look like pustular candida
Bacterial folliculitis – as above
Psoriasis – gluteal cleft
Tinea – same locations

90. Candidiasis KOH for pseudohyphae and spores Woods Light
May be impossible to tell visually from tinea.
Woods Light
Culture. Nickersons (+)
Remember yeast part of normal flora.
Add up the evidence

91. Candidiasis

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 rash
Angular chelitis.
Treat co-existent bacterial infection if present.

93. THE END