Download MBBS Dermatology PPT 8 Fungal Infections Lecture Notes

Download MBBS (Bachelor of Medicine, Bachelor of Surgery) Dermatology PPT 8 Fungal Infections Lecture Notes

Fungal infections

Natural defence against fungi

? Fatty acid content of the skin

? pH of the skin, mucosal surfaces and body fluids

? Epidermal turnover

? Normal flora (bacterial; fungal)
Predisposing factors

? Climate: Tropical, profuse sweating
? Manual labor population
? Lower socioeconomic status
? Friction with clothes, synthetic innerwear
? Malnourishment
? Immunosuppressed patients: HIV infection/AIDS,
congenital immunodeficiencies, patients on
corticosteroids, immunosuppressive drugs
(posttransplant), diabetes mel itus

Fungal infections: Classification

v Superficial cutaneous:

Surface infections e.g., Pityriasis versicolor,
Dermatophytosis, Candidiasis, Tinea nigra, Piedra

v Subcutaneous:
Mycetoma, Chromoblastomycosis, Sporotrichosis,
v Systemic: (opportunistic infection)
Histoplasmosis, Candidiasis, Zygomycosis
Pityriasis versicolor

Etiologic agent: Malassezia furfur (formerly:
Clinical features:
? Common among youth
? Genetic predisposition, familial occurrence
? Multiple, discrete, discoloured, macules, may be
fawn, brown, grey colored or hypopigmented
? Pinhead sized to large sheets of discolouration
?Seborrheic areas, upper half of body: trunk, arms,

neck, abdomen

P.versicolor : Investigations

? Wood's Lamp (365 nm) examination: Yel ow
? KOH preparation:

"Spaghetti and meatbal " appearance

Coarse mycelium, fragmented to short filaments 2-5
micron wide, together with spherical, thick-wal ed
yeasts 2-8 micron in diameter, arranged in grape like
Treatment P. versicolor

? Ketoconazole, Clotrimazole, Miconazole,
Terbinafine, Selenium sulfide
? Fluconazole 400 mg single dose
? Ketoconazole 200mg OD x 14days
? Oral griseofulvin & oral terbinafine: NOT effective.
? Hypopigmentation wil take weeks to fade
? Scaling wil disappear soon

Treatment P. versicolor

?P. versicolor recurs if predisposing factors not taken

care of

?Minimizing sweat, frequent washes and control of

immunosuppression causes long remission
? Treatment: Oral Itraconazole, Ketaconazole,

Fluconazole or topical Ketoconazole shampoo.

Tinea nigra palmaris

Etiology: Hortaea werneckii (formerly: Exophiala

wernecki )

Clinical features: Asymptomatic superficial infection

of palms; deeply pigmented, brown or black macular,
non-scaly patches, resembling a silver nitrate stain.
? Treatment: Topical antifungals (e.g.,


Black piedra

?Etiology: Piedraia hortae
?Distribution: South America and in South-East Asia
?Clinical features: Hard, dark, multiple superficial

nodules; firmly adherent black, gritty, hard nodules

on hairs of scalp, beard, moustache or pubic area,

hair may fracture easily.


Shaving or cutting the hair.

White piedra

Etiology: Trichosporon beigeli

Clinical features:
Soft, white, grey or brown superficial nodules on
hairs of the beard, moustache , pubic areas.
Hair shaft weakened and breaks.
Treatment: Shaving or cutting the hair. Responses to

topical antifungals, azoles and al yamines have been
reported but are unpredictable.


?Three genera:

Microsporum, Trichophyton, Epidermophyton

?They can be zoophilic, anthropophilic or geophilic.
?Thrive on dead, keratinized tissue - within the stratum

corneum of the epidermis, within and around the fully
keratinized hair shaft, and in the nail plate and
keratinized nail bed.
Dermatophytes are keratinophillic

?The topmost layer (stratum corneum) is a sheet of non

-nucleated cel s (corneocytes) containing protein ?
keratin ? stuck together forming a tough barrier

? This barrier, when dry al ows fungi to stay on the

surface but stops them from piercing it

? However, when moist, it becomes porous and sucks in

the fungi like a sponge.

Dermatophytosis (Ringworm)

?Head: Tinea capitis
?Face: Tinea faciei
?Beard: Tinea barbae
?Trunk/body: Tinea corporis
?Groin/gluteal folds: Tinea cruris
?Palms: Tinea manuum
?Soles: Tinea pedis
?Nail: Tinea unguium
Tinea capitis

Invasion of hair shaft by a dermatophyte fungus.
Clinical features:
?Common in children with poor nutrition and hygiene.

Rare after puberty because sebum is fungistatic.

?Wide spectrum of lesions - a few dull-grey, broken-off

hairs, a little scaling to a severe, painful, inflammatory
mass covering the scalp.

?Partial hair loss is common in al types; cicatricial

(scarring ) alopecia can occur

Tinea capitis

Endothrix and Ectothrix
Term used to indicate infection of hair shaft, spores
lying inside or outside hair shaft.
4 varieties:
?Gray patch
?Black dot
?Kerion (similar to a `boil')
Non inflammatory Tinea capitis:

Black dot/ Grey patch

? Breakage of hair gives rise to `black dots'
?Patchy alopecia, often circular, numerous broken-off

hairs, dull grey

? Inflammation is minimal
?Wood's lamp examination: green fluorescence

(occasional non-fluorescent cases)

Tinea capitis: Kerion

Inflammatory variety
Painful, inflammatory boggy swel ing with purulent
Hairs may be matted, easily pluckable
Co-infection with bacteria is common
May heal with scarring alopecia
Tinea capitis: Favus

Inflammatory variety
Yel owish, cup-shaped crusts (scutula) develop around

a hair with the hair projecting central y. Adjacent
crusts enlarge to become confluent mass of yel ow

Hair may be matted
Extensive patchy hair loss with cicatricial alopecia

Tinea faciei

Erythematous scaly patches on the face
Annular or circinate lesions and induration
Itching, burning and exacerbation after sun exposure
Seen often in immunocompromised adults
Tinea barbae

Ringworm of the beard and moustache areas
Invasion of coarse hairs
Disease of the adult male
Highly inflammatory, pustular fol iculitis
Hairs of the beard or moustache are surrounded by

inflammatory papulopustules, usual y with oozing or
crusting, easily pluckable

Persist several months

Tinea corporis

Lesions of the trunk and limbs, excluding ringworm of

the specialized sites such as the scalp, feet and groins

The fungus enters the stratum corneum and spreads

centrifugal y. Central clearing results once the fungi
are eliminated.

A second wave of centrifugal spread from the original

site may occur with the formation of concentric
erythematous inflammatory rings.
Tinea corporis

Classical lesion:
Annular patch or plaque with erythematous

papulovesicles and scaling at the periphery with
central clearing resembling the effects of ring worm.

Polycyclic appearance in advanced infection due to

incomplete fusion of multiple lesions

Sites: waist, under breasts, abdomen, thighs etc.

Tinea cruris

Erythematous plaques, curved with wel demarcated

margins extending from the groin down the thighs.

Scaling is variable, and occasional y may mask the

inflammatory changes.

Vesiculation is rare
Tinea mannum

Two varieties:
Non inflammatory: Dry, scaly, mildly itchy
Inflammatory: Vesicular, itchy

Tinea pedis

Wearing of shoes and the resultant maceration
Adult males commonest, children rarely
Peeling, maceration and fissuring affecting the lateral

toe clefts, and sometimes spreading to involve the
undersurface of the toes.

Two varieties:
Dry, scaly, mildly itchy, extensively involved ('moccasin foot


Vesicular, itchy, with inflammatory reactions affecting

al parts of the feet
Tinea pedis : Prevention

Keeping toes dry
Not walking barefoot on the floors of communal

changing rooms

Avoiding swimming baths.
Avoid closed shoes
Avoid nylon socks
Use of antifungal powders

Tinea Unguium

Dirty, dull, dry, pitted, ridged, split, discoloured,
thick, uneven, nails with subungual hyperkeratosis
Different types described depending on the site of nail
involvement and its depth.
Distal and lateral onychomycoses
Proximal subungual onychomycoses
White superficial onychomycoses
Total dystrophic onychomycoses

Treatment: Ringworm

Topical: Ketoconazole, Clotrimazole, Miconazole,

Butenafine, Terbinafine.

Vehicle: Lotions, creams, powders, gels are available.

Treatment: Tinea

Oral: Griseofulvin 250 mg BD
Fluconazole 150 mg weekly
Ketoconazole 200 mg OD
Terbinafine 250 mg OD
Itraconazole 200 mg OD
Duration: T. capitis - 6 weeks
T. faciei - 4 weeks
T. cruris - 4 weeks
T. corporis - 4-6 weeks
T. manuum/pedis - 6-8 weeks
Shorter duration required for terbinafine & itraconazole
Treatment: Tinea unguium

The same line of Treatment for 3 months (fingernail)

to 6 months (toenails)

8% Ciclopirox olamine lotions for local application
Amorolfine nail lacquer painted weekly
Pulse Therapy
Terbinafine: 250mg given 1BD x 1week / per month
Itraconazole: 200mg given 1BD x 1week/month
3 pulses for fingernails, 4 pulses for toenails.

Treatment Principles

Patient should be explained clearly about the

predisposing factors

Need for personal hygiene, proper clothing should be


Selection of topical medication:
Do not use ointments on areas of friction or on greasy


Do not rub creams/ointments in groin folds
Choose steroid combinations only if itch is a major

complaint. Do not use antifungal creams in

combination with potent steroids
Treatment Principles

Dermatophytosis wil take 3-4 weeks to resolve and

patient should be told about the need for complete

treatment. Treat 1 week beyond apparent cure.

Need for hygiene, proper clothing.

Onychomycosis requires 3-6 months of treatment.

Treat 4 weeks beyond apparent cure.

Temporary relief should not be mistaken for cure


Causative organism:
Candida albicans, Candida tropicalis, Candida


Sites of affection:
Mucous membrane
Candidiasis : Mucosal

Oral thrush:
Creamy, curd-like, white pseudomembrane, on

erythematous base


Immunocompetent patient: cheeks, gums or the


Immunocompromised patients: affection of tongue

with extension to pharynx or oesophagus; ulcerative

lesions may occur.

Angular cheilitis (angular stomatitis / perleche):

Soreness at the angles of the mouth

Candidiasis : Mucosal

Vulvovaginitis (vulvovaginal thrush): Itching and

soreness with a thick, creamy white discharge

Tiny papules on the glans penis after intercourse,

evolve as white pustules or vesicles and rupture.

Radial fissures on glans penis in diabetics.

Vulvovaginitis in conjugal partner

Candidiasis - Flexural

Intertrigo: (Flexural candidiasis):
Erythema and maceration in the folds; axil a, groins and


Napkin rash:
Pustules, with an irregular border and satel ite lesions

Candidiasis: Nail

Chronic Paronychia:
Swel ing of the nail fold with pain and discharge of


Chronic, recurrent.
Superadded bacterial infection
Destruction of nail plate.
Treatment of candidiasis

Treat predisposing factors like poor hygiene,

diabetes, AIDS, conjugal infection

Clotrimazole, Miconazole, Ketoconazole, Ciclopirox


Ketoconazole 200mg, Itraconazole 100-200mg and

Fluconazole 150mg

This post was last modified on 07 April 2022