2-Cutaneous fungal infections

What are the 2 growth forms of fungi?

1) Moulds (hyphae)

2) Yeasts

Do fungi reproduce sexually or asexually?

Both

What are the lifestyles of fungi?

- Saphrophytes

- Symbionts

- Pathogens

What is a saphrophyte?

Decomposes decaying organic matter

Which types of fungi infect superficially?

- Dermatophytes

- Malassezia

- Candida

Which types of fungi infect systemically?

- Candida

- Aspergillus

What are dermatophytes?

Group of moulds that cause disease in skin, hair and nail

What does geophilic mean?

Soil is the source

What does zoophilic mean?

Animals are the source

What does anthropophilic mean?

Humans are the source

What is tines pedis?

Athlete's foot

What is tinea unguium?

Fungal nail disease

What is tinea cruris?

Jock itch - fungal disease of the groin

What is tinea corporis?

Ringworm

What is tinea capitis?

Scalp ringworm

What are the presentations of tinea pedis?

- Itching, flaking, fissuring of skin

- Plantar foot dry and scaly

- Can infect toe nails

What is the typical cause of tinea pedis?

Trichophyton interdigitale

What is onychomycosis?

Dermatophyte infection of the nails

What are the 3 starting presentations of onychomycosis?

- Distal-lateral subungual onychomycosis

- Superficial onychomycosis

- Proximal onychomycosis

What does onychomycosis lead to if left untreated?

Total nail dystrophy

What are the presentations of tinea cruris (jock itch)?

- More prevalent in men

- Itching, scaling, erythematous plaques

What are the causes of tinea cruris?

- T. Rubrum

- T. Indotineae

What is the complication with T. Indotineae?

Resistant to antifungal terbinafine

What are the presentations of tinea capitis?

- More prevalent in pre-pubescent children

- Slight inflammation, scaly patches with alopecia

What is kerion celsi?

An infection of the hair follicles of the scalp derived from zoophilic dermatophytes like tinea capitis, resulting in boggy inflamed lesions

What are the presentations of tinea corporis?

- Circular, single or multiple erythematous

- Extend from scalp or groin

For mild dermatophyte infections, what is the treatment?

Topical antifungal therapy with:

- Terbinafine

- Clotrimazole

- Miconazole

For severe dermatophyte infections, what is the treatment?

Systemic oral antifungal therapy with:

- Terbinafine

- Griseofulvin

- Itraconazole

What must you always treat tinea capitis with?

Systemic oral antifungal

What is Malassezia?

- organisms

- Commonly found on skin and ear

What causes malassezia?

- Pityriasis versicolor

What are the presentations of pityriasis versicolor?

- Prevalent between puberty and middle age

- Hyper or hypopigmented lesions

- Seen in upper trunk

What is the treatment of pityriasis versicolor?

Topical antifungals:

- Clotrimazole

Systemic oral antifungals:

- Fluconazole

- Itraconazole

Where does candida colonise?

Mucosal surfaces and GI tract in healthy individuals

What are fungal cells stained with?

Calcofluor

What is acute pseudomembranous oral candidiasis?

- Prevalent in younger patients or due to steroid inhalers for asthma

- Low CD4 count

- Yellow mottling of the oropharynx

What is chronic atrophic candidiasis?

- Denature stomatitis

- Prevalent in older patients

What is candida vulvovaginitis?

- Prevalent in women of child-bearing years

- Itching, burning sensation, discharge

What is the treatment for superficial candidiasis?

- Usually -azoles: oral fluconazole

- Topical clotrimazole pessaries

When mustn't oral -azoles be used to treat superficial candidiasis?

For pregnant women - use topical -azoles

What are the presentations of candida oesophagitis?

- Prevalent ion patients with HIV

- Pain/difficulty swallowing

What are the treatments of systemic candidosis?

- Azoles e.g fluconazole (oral)

- Echinocandins e.g anidulafungin (IV)

- Liposomal amphotericin B (IV)

What sort of fungi is Aspergillus?

Mould

What organ does Aspergillus target?

Lungs

What is the allergic reaction to Aspergillus?

Bronchopulmonary aspergillosis

What is the chronic infection to Aspergillus?

Chronic pulmonary aspergillosis (CPA)

What Aspergillus infects the immunocompromised?

Invasive pulmonary aspergillosis

What are Aspergillomas?

- Present in patients with previous TB infection, forming a ball of fungus

- Usually are slow-growing but can break up causing fatalities

What are the presentation of allergic bronchopulmonary aspergillosis?

- Wheezing

- Dyspnoea

- Bronchiectasis

- Raised IgE

What is the treatment for CPA and invasive aspergillosis?

- Itraconazole

- Variconazole

- Amphotercin B