Zoonotic Fungal Diseases

Question 1

Dermatophytosis

Answer 1

• Dermatophytes: Skin Fungus
• Fungal infection that affects keratinized tissue in the body
◦ Keratinized tissue include: Skin, Hair, & Nails
• Reservoirs of fungal infection/agent include:
◦ Animals
◦ Humans
◦ Soil
• Appearance:
◦ More plant like appearance
◦ Contain Arthrospores
• Causative Fungi:
◦ Microsporum spp
◦ Trichophyton spp

Question 2

Microsporum canis

Answer 2

Fungal organism that is most commonly involved in animal to human tranmission of ringworm

• Clinical Signs:
◦ Round lesions of alopecia that is scaley & crusty
‣ Typical appearance
◦ Face, ears, & extremities most often involved
◦ Some infected animals may not show a lesion
◦ Kerion: Raised round lesion
• Diagnosis:
◦ Microscopic examination of skin scraping
‣ Stain w/ myethlyn blue & look for the arthrospores
◦ Fungal culture by sending plucked hair
‣ Growth: White Cotton like appearance
‣ Incubation: 1 week
◦ Wood’s lamp examination, infected tissue fluoresces yellow-green color
‣ Spurious: False glowing/fluoresces from the woods lamp due to the application of neosporin or other lotion/salve
‣ The woods lamp is using the first step ->
• Treatment
◦ Spot treatment: Single Lesion
‣ Clip and clean around lesion
‣ Apply topical antifungal
◦ Whole body treatment: Multiple Lesions
‣ Bathe w/ antifungal shampoo
‣ Administer oral antifungal medication
• Griseofulvin
◦ Treat based on clinical signs/symptoms
• Transmission:
◦ Direct contact w/ fungi
◦ Direct contact with infected skin, hair or contaminated inanimate objects
• Human Symptoms: Zoonotic
◦ Spreading ring shaped lesions on the head and/or body
‣ Periphery is reddish w/ vesicle pustule formation
◦ Skin surface may be dry & scaly or moist & crusted
◦ Healing begins at center of lesion
• Incubation Period: 4-14 days
• Diagnosis:
◦ Skin Scrape - Microscopic exam
◦ Fungal Culture
◦ Woods Lamp Examination
• Control/Prevention:
◦ Treat infected people to prevent spread of infection to others
‣ Apply topical & bandage to cover if needing to go out to public places
◦ Treat infected animals to prevent transmission
◦ Clean & disinfect inanimate nieces in contact w/ infected animals
‣ Lysol is effective

Question 3

Dermatophytosis mode of transmission?

Answer 3

Direct contact with infect skin, hair, or inanimate object

Question 4

Dermatophytosis diagnosis?

Answer 4

Skin Scrape
Fungal Culture
Woods Lamp

Question 5

Dermatophytosis symptoms

Answer 5

Humans:
Ring shaped lesions on head & body
Periphery is reddish with vesicle
healing begins at the center of the lesions

Animals:
Round lesions of alopecia, scaling & crusting
May have no lesions

Question 6

Dermatophytosis incubation period

Answer 6

4-14 days

Question 7

Dermatophytosis woods lamp examination?

Answer 7

Infected tissue fluoresces yellow-green color

Question 8

Dermatophytosis Treatment

Answer 8

clip/clean & antifungal