Fungal Infections of the Skin

Question 1

Name the 3 cutaneous mycoses

Answer 1

Dermatophytosis, tinea versicolor, tinea nigra

Question 2

How many genera of fungi can dermatophytosis be caused by?

Answer 2

3

Question 3

What does dermatophytosis infect?

Answer 3

Superficial keratinized structures

Question 4

What does dermatophytosis produce?

Answer 4

Keratinases

Question 5

Symptoms of dermatophytosis are called what?

Answer 5

Tinea

Question 6

How is dermatophytosis transmitted?

Answer 6

Fomites or autoinnoculation

Question 7

How do you diagnose dermatophytosis?

Answer 7

KOH mount, culture, PPD, Wood’s lamp exam

Question 8

How do you treat dermatophytosis?

Answer 8

Topical antifungal or oral griseofulvin

Question 9

What is tinea versicolor?

Answer 9

Hypo or hyperpigmented areas on trunk, back, or abdomen

Question 10

Tinea versicolor is caused by what?

Answer 10

Overgrowth of normal flora Malassezia

Question 11

How do you diagnose tinea versicolor?

Answer 11

KOH mount of skin scrapings

Question 12

How do you treat tinea versicolor?

Answer 12

Selenium sulfide or oral azoles

Question 13

What is tinea nigra?

Answer 13

Infection of injured extremity by werneckii from soil that causes a dark brown spot

Question 14

How do you diagnose tinea nigra?

Answer 14

KOH mount for branching hyphae with dark pigment, culture on Sabourad’s agar for shiny black colonies

Question 15

How do you treat tinea nigra?

Answer 15

Salicyclic acid plus topical azole

Question 16

What are the subcutaneous mycoses?

Answer 16

Sporotrichosis, chromomycosis, mycetoma

Question 17

What causes sporotrichosis?

Answer 17

Sporothrix species, a thermally dimorphic fungi, enters the skin through a small injury like a thorn

Question 18

Manifestation of sporotrichosis?

Answer 18

Painless ulcer that spreads up lymphatics. If COPD- pulmonary. If immunosuppressed- meningitis or disseminated

Question 19

How do you diagnose sporotrichosis?

Answer 19

Biopsy for round or cigar shaped yeasts and culture pus at room temp for hyphae that look like daisies

Question 20

How do you treat sporotrichosis?

Answer 20

Oral azole, more serious form- amphotericin b

Question 21

What causes chromomycosis?

Answer 21

Tropical soil fungi enter through injuries to the feet

Question 22

Manifestation of chromomycosis?

Answer 22

Gradually spreading wart-like or plaque lesions with scattered black dots

Question 23

Diagnosis of chromomycosis?

Answer 23

KOH mount for gray or black septate hyphae. Biopsy dark spot for dark brown round fungal cells inside leukocytes or giant cells

Question 24

Treatment of chromomycosis?

Answer 24

Oral flucytosine, thiabendazole, local surgery, heat

Question 25

What is mycetoma?

Answer 25

A rare infection of wounds on the extremities from Petriellidum or Madurella from the soil

Question 26

What are the clinical manifestations of mycetoma?

Answer 26

Forms abscesses, granulomas, and pus with granules

Question 27

How do you diagnose and treat mycetoma?

Answer 27

Biosy and treat with surgery, IV amphotericin B, and oral azole