Fungal infections and skin infestations

Question 1

Types of cutaneous fungal infections

Answer 1

superficial 
- stratum corneum, hair, nails
subcutaneous
- dermis, subcutis
systemic
- can be blood borne

Question 2

What are dermatophytes?

Answer 2

Invade and multiply in keratinised tissue

Question 3

3 types of dermatophytes?

Answer 3

Microsporum
Trichophyton (most common)
Epidermophyton

Question 4

Transmission of dermatophytes?

Answer 4

Athropophilic, zoophilic ,geophilic

e.g. human-human, animal-human, soil-human

Question 5

What is tinea?

Answer 5

ringworm

Question 6

What does tinea corporis look like and which part of the body does it affect?

Answer 6

multiple annular scaly plaques affecting the body

Question 7

What does tinea manuum look like and which part of the body does it affect?

Answer 7

asymmetrical involvement, with scaling more prominent in one palm than the other, spreading out from the wrists proximally with an advancing edge

Question 8

What does tinea pedis look like and which part of the body does it affect?

Answer 8

Athlete’s foot

• in between toe webs
• white maceration
• severe: scaling, pustules, erythema more prominent
• can spread with an advancing edge
• called Moccasin feet when more widespread

Question 9

What does tinea unguium look like and which part of the body does it affect?

Answer 9

onychomycosis - fingers and toes
Common esp on feet.
- distal white discolouration
- loss of nail plate
- onycholysis
- hyperkeratosis

may be mistaken for psoriasis (common)

Question 10

What does tinea capitis look like and which part of the body does it affect?

Answer 10

Scalp
More common in afro-caribbean population and increased genetic risk
- scaling and hair loss
- can lead to boggy swelling known as keryon

Question 11

Investigations for fungal infections?

Answer 11

• skin scrapings - scale
• nail clippings and subungual debris
• hair pluckings
• wood’s light - fungi fluoresce under UV light

Question 12

Investigations for fungal infections?

Answer 12

• skin scrapings - scale
• nail clippings and subungual debris
• hair pluckings
• wood’s light - fungi fluoresce under UV light

Question 13

Treatment of fungal infections?

Answer 13

Localised skin infections - topical treatment:

• topical terbinafine
• azoles - ketoconazole, myconazole
• polyenes - nystatin

Nails, scalp, hair, widespread skin infection, immunocompromised - systemic treatment:

• terbinafine
• azoles - itraconazole
• griseofulvin (children)