Superficial fungal infections

Question 1

What are the types of infection?

Answer 1

1. Dermatophyte (ringworm)
   - Skin, hair, nails
2. Pityriasis versicolour
3. Candidiasis

Question 2

What is the source of dermatophyte infections?

Answer 2

Humans, animals, environmental

Question 3

What is the pathogenesis of dermatophyte infections?

Answer 3

Digest keratin (skin, hair, nails)

Question 4

What are the 3 species of dermatophyte infections?

Answer 4

Microsporum spp.
Epidermophyton spp.
Trichophyton spp.

Question 5

How to identify dematophyte infections?

Answer 5

Characteristic macroconidia
KOH preparation with skin scrapings

Question 6

Which fungi is pityriasis versicolour caused by?

Answer 6

Malassezia furfur (lipophilic yeast)

Question 7

Where does Candidiasis infect?

Answer 7

Oropharynx and/or vagina
- Mucosal surfaces with existing rich flora

Question 8

What are the risk factors?

Answer 8

Antibiotics, infancy, old age, pregnancy

Question 9

What infection does it cause?

Answer 9

• Nail infections (wet hands)
• Severe infections in immunocompromised (may be presenting symptoms in AIDS)
• Oral thrush
• Oesophagitis

Question 10

What is the fungi that causes Candidiasis?

Answer 10

Candida albicans (dimorphic)
- most common single species
- susceptible to most anti-fungal drugs (unless previous long-term exposure)

Other Candida species (not dimorphic)
- C.glabrata, C.tropicalis, C.parapsilosis
- More resistance to antifungals
- Increasing proportion of all candida infections