Fungal pathogens

Question 1

properties of fungi

Answer 1

• Eukaryotic
• Single celled to macroscopic
• Reproduce asexually + sexually with spores

Question 2

What are the growth forms of fungi

Answer 2

Hypha - Moulds

Yeast cells - yeasts

Question 3

What are the 3 lifestyles of fungi

Answer 3

• Saprophytes - decaying organic matter
• Plant pathogens
• Animal pathogens

Question 4

What are the 3 type of fungal disease

Answer 4

• Superficial infection - skin, hair, nails etc
• Subcutaneous infection - subcutaneous tissue
• Systemic infection - deep-seated organs affected

Question 5

What are dermatophytes

Answer 5

Group of moulds causing superficial infections

- originate in soil, animals or humans

Question 6

Athletes foot

Answer 6

Tinea pedis

• Typical cause Trichophyton rubrum
• itching, flaking, dry skin

Question 7

Fungal nail infection

Answer 7

Tinea unguium

• Typical cause Trichophyton rubrum + T.interdigitale
• Thickening, discolouring, dystrophy

Question 8

Jock itch

Answer 8

Tinea cruris

• Typical cause T.rubrum
• Itching, scaling, erythematous plaques

Question 9

Scalp ringworm

Answer 9

Tinea capitis

• Mainly seen in pre-pub children
• scaly patches, black dots, severe inflammation

Question 10

What are Kerion celsi

Answer 10

Inflamed lesions usually from zoophilic dermatophytes

Question 11

Ringoworm

Answer 11

Tinea corporis

• Typical cause zoophilic/anthropophilic dermatophytes
• Circular erythematous plaques
• May invade follicle

Question 12

What is topical antifungal therapy + 3 examples

Answer 12

Used for mild diseases

• Terbinafine
• Clotrimazole
• Miconazole

Question 13

How to treat tinea capitis?

Answer 13

Use systemic oral antifungals such as Griseofulvin, terbinafine, itraconazole

Question 14

What is Pityriasis versicolor

Answer 14

• Hyper/hypo pigmented lesions

- between puberty and middle age

Question 15

What is Malassezia

Answer 15

• Genus of yeasts
• part of normal skin flora in humans
• Causes Pityriasis versicolor

Question 16

Diagnosis of Pityriasis versicolor

Answer 16

Culture looks like spaghetti and meatballs

- Presence of both yeast cells and hyphal segments

Question 17

Treatment of Pityriasis versicolor

Answer 17

Topical antifungals

• Clotrimazole
• If fails then oral fluconazole

Question 18

Candida

Answer 18

Large genus of yeasts

• colonises mucosal surfaces and GI tract
• Causes thrush
• Cause of systemic infection if present in blood

Question 19

4 types of superficial candida infection

Answer 19

• Acute pseudo-membranous
• Chronic atrophic
• Angular cheilitis
• Chronic hypoplastic

Question 20

Candida Vulvovaginitis

Answer 20

Inflammation of vaginal epithelium - burning sensation, Pruritis

Question 21

Diagnosis and treatment of superficial candidosis

Answer 21

Diagnosed with culture and antifungal sensitivity testing

- Oral azoles highly effective

Question 22

Why not give oral azoles to pregnant women

Answer 22

Increases the risk of teratologies in the foetus

• Use topical azoles
• TTT treat thrush topically

Question 23

Systemic Candidosis

Answer 23

Candida sp can infect any organ in the body.

• Defined by site of infection
• Candida albicans most common

Question 24

Candida oesophagitis

Answer 24

Mainly in HIV

• pain swallowing/ eating
• Diagnosed by endoscopy

Question 25

Candidaemia

Answer 25

Candida in blood

- Very rare, treated with antifungal treatment

Question 26

Candida chorioretinitis and endophthalmitis

Answer 26

Causes occular candidosis

Question 27

Candida endocarditis

Answer 27

Vegetations seen on the heart valves, fever, fatigue

- Treated with valve replacement

Question 28

UT Candida infection

Answer 28

Ascends from genital tract infection

• More common in women, diabetics, ICU patients
• Candiduria can be used

Question 29

What is Candiduria and why is it necessary

Answer 29

Used to treat UT Candida infection

• Isolation of Candida from urine
• Used as there are few antifungals secreted in urine

Question 30

Candida peritonitis

Answer 30

• Perforation of bowel during peritoneal dialysis
• Diagnosis by culture of Candida in peritoneal fluid
• Fever, nausea abdominal pain

Question 31

Diagnosis and Treatment of Systemic Candidosis

Answer 31

• Diagnosis by culture
• Treatment depends on they type of Candida, sensitivity and severity
• Echinocandins, Azoles

Question 32

What is Aspergillus

Answer 32

Genus of moulds - filamentous fungi

• produce spores
• Usually colonises airways

Question 33

Aspergillosis

Answer 33

Broad term based on the reaction to inhaled Aspergillus

Question 34

Aspergilloma

Answer 34

Non invasive/ space occupying fungal ball in lung cavity

- If the ball breaks it can cause haemoptysis and can be fatal

Question 35

Allergic Bronchopulmonary aspergillosis

Answer 35

• Usually in patients with asthma and CF
• Airway inflammation, breathlessness, loss of lung function
• IgE and G reaction to aspergillus

Question 36

Chronic pulmonary aspergillosis

Answer 36

• COPD
• chronic respiratory symptoms
• positive for aspergillus IgE

Question 37

Invasive aspergillosis

Answer 37

• Angioinvasion of lung tissue

- Haematological malignancies

Question 38

Aspergillosis, diagnosis and treatment

Answer 38

Diagnosis - culture, serology
Treatment:
Aspergilloma - resection
Allergic asp - steroids/antifungals
CPA and invasive asp - antifungals - azoles