4 fungal infections lecture
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Transcript of 4 fungal infections lecture
Superficial Fungal
Infections
By
Mengistu Hiletework ( M.D.)
Consultant
Dermatovenereologist
Introduction
• Epidemiology
• Sources of infection
Anthropophilic
Zoophilic
Geophilic
Key features
•Cutaneous fungal infections are broadly divided into those
that are limited to the stratum corneum, hair and nails, and
those that involve the dermis and subcutaneous tissues
•Superficial fungal infections of the skin are due primarily to
dermatophytes and Candida species.
•Systemic or 'deep' mycoses of the skin usually represent
hematogenous spread or extension from underlying
structures.
•In the immunocompromised host, opportunistic fungi, e.g.
Aspergillus and Mucor, can lead to both cutaneous and
systemic infections.
•The superficial mycoses are due to fungi that
only invade fully keratinized tissues, i.e. stratum
corneum, hair and nails.
•The superficial mycoses can be further
subdivided into those that induce minimal, if
any, inflammatory response,e.g. pityriasis
(tinea) versicolor, and those that do lead to
cutaneous inflammation, e.g.dermatophytoses
Dermatophytes
and
Dermatophytosis
What are they?
What do they look like?
Genera of dermatophytes
• Epidermophyton
• Trichophyton
• Microsporum
Types of dermatophytosis
• Tinea corporis
• Tinea faciei
• Tinea barbae
• Tinea cruris
• Tinea of hand and feet
• Tinea capitis
• Onychomycosis
• Fungal folliculitis( Majocchi granuloma)
• Tinea incognito
• Dermatophytids
Susceptibility Factors
• Primary immunodeficency syndromes
• Acquired Immunodeficency syndrome
(AIDS)
• Connective tissue disease
• Cancer chemotherapy
• Defective cutaneous barrier ; eg.ichtyosis
• Use of topical corticosteroids
Susceptibility Contd……
• Occlusion
• Genetic susceptibility for certain forms of
fungal infections
Tinea corporis(TC)
• All superficial dermatophyte infections of the skin other
than those involving the scalp, beard, face, hands, feet
and groin. eg.Tinea gladiatorum
• Progressive central clearing, hence ringworm.
• in some cases concentric or polyciclic
Tinea corporis Cont…. Diagnosis
Skin scraping and then Potassium hydroxide
(KOH) mount or Culture
Tinea corporis, Cont…. Treatment
• Topical therapy
Clotrimazole,Miconazole,ketoconazole, Sulconazole,Oxiconazole,Econazole,Terbinafine between two-four weeks, usually twice a day.
• Systemic antifungal treatment
for extensive disease or fungal folliculitis
Griseofulvin, 500-1000 mg/day for 4-6 weeks and for children 10-20 mg/kg/day
Terbinafine, 250mg/day; 1-2 weeks
Itraconazole ;200mg/day for one week
Fluconazole; 150 mg once a week for 4 weeks
Tinea corporis Contd…. Differential Diagnosis
• Pityriasis rosea
• Impetigo
• Nummular dermatitis
• Secondary and tertiary syphilids
• Seborrheic dermatitis
• Psoriasis
Tinea faciei
• Typical annular rings are usually lacking
• Lesions are photosensitive
• A misdiagnosis of lupus erythematosus is
often made
• For fungal folliculitis→oral medication
• If no folliculitis→topical therapy
Tinea barbae
• Tinea mycosis or barber’s itch
• Mostly one sided and chiefly among those
in contact with farm animals
• Two types; deep, nodular suppurative
lesions and superficial crusted, partially
bald patches with folliculitis
Tinea barbae, Cont….
• D/Dg :-
Staphylococcal folliculutis ( Sycosis
vulgaris)
Herpetic infections
• Treatment:-
Oral antifungal agents, and topical agents
are only helpful as adjunctive therapy
Tinea cruris
• Also known as jock itch and crotch itch
• Upper and inner surface of thighs,
especially during the summer when the
humidity is high
• Scrotum rarely involved
Tinea cruris Cont….
• Usually moist, more inflammatory and associated with satellite macules.
• Candida often produces collarette scales and satellite pustules.
D/Dg: -
Erythrasma
Seborrheic dermatitis
Pemphigus vegetans
Intertriginous psoriasis
Tinea of hand and feet
• Athlet’s foot is the most common fungal
disease
• T.rubrum causes the majority of infections;
may be an autosomal –dominant
predisposition to this form
Types of Tinea pedis
• Three Types of Tinea pedis:-
1)Multinocular bullae involving the thin skin of the plantar arch and along the sides of the feet and heel
2)Erythrasma and desquamation between the toes
3)Relatively non inflammatory type characterized by a
dull erythema and pronounced silvery scaling that may
involve the entire sole and sides of the feet( T. rubrum)
Hand may also be involved.
Treatment
• Reduction of perspiration and enhance-
ment of evaporation from the crural area
• Keep as dry as possible by wearing loose
kept clothing
• Specific topical and oral treatment, same
as described for tinea corporis
Tinea palmaris
Tinea pedis
Tinea pedis, D/Dg…
• Simple maceration caused by a closed
web space
• Gram negative toe-web infection
Diagnosis of Tinea pedis/
palmaris • Skin scrapings
• Bullae should be unroofed and either the entire roof mounted intact or scrapings made from the underside of the roof
• Sabouraud dextrose agar, Sabouraud agar with chloramphenicol,mycosel agar,or DTM(dermatophyte test medium)
• Chloramphenicol, mycosel agar,or DTM inhibit growth of bacteria or saprophyte contaminants.
• Mycosel agar and DTM may inhibit some pathogenic nondermatophytes.
• The alkaline metabolites produced by growth of dermatophytes change the color of the PH indicator in DTM medium from yellow to red.
Tinea pedis,Treatment
• Clotrimazole,miconazole,oxiconazole,econazole,ketoconazole,
terbinafine
• Toes separated by foam or cotton inserts, when maceration between toes
• Topical antibiotics like gentamycin against gram- negative organisms in some moist interdigital lesions.
In ulcerative types systemic antibiotics
• Fungal infections of the hands and feet with systemic griseofulvin, terbinafine, itraconazole and fluconazole with a similar regimen to tinea corporis
Tinea pedis Cont…
• Prophylaxis:
1) Since hyperhidrosis is a predisposition factor for tinea infections, toes should be thorougly dried after bathing.
2)Antiseptic powders after bathing, e.g.. plain talc, corn starch, rice powder dusted into socks and shoes to keep the feet dry.
Tinea capitis
• By all pathogenic dermatophytes except
for Epidermophyton floccosum and
Trichophyton concentricum
• Pet exposure→M.canis
• Children can be carriers and still
asymptomatic
Tinea capitis cont…Types
• Seborrheic like scaling.
• Inflammatory kerion.
• Favus.
Diagnosis
• From a highly inflammatory plaque two or three loose hairs are carefully removed with epilating forceps
• Hairs are placed on a slide covered with a drop of 10% to 20% KOH solution.
• Culture with Sabouraud dextrose agar with chloramphenicol
• Diagnosis is made by the gross appearance of the culture growth, together with the microscopic appearance
Tinea capitis, cont….
Differential Diagnosis
• Chronic staphylococcal folliculitis
• Pediculosis capitis
• Psoriasis
• Seborrheic dermatitis
• Secondary syphilis
• Alopecia areata
• Lupus eryrhematosus
• Lichen planus
Tinea capitis,…Treatment
• Griseofulvin tablets; griseofulvin V oral suspension is less readily absorbed
• Fluconazole, 6mg/kg/day for 2-3 weeks
• Terbinafine
• Itraconazole, 5mg/kg/day for 2-3 weeks
• Without medication there is spontaneous clearing at about the age of 15, except with T. Tonsurans , which often persists in adult life.
Onychomycosis
• Infection of the nail plate
• T.rubrum accounts for most cases, but
many fungi like E.floccosum and various
species of Microsporum and Trichophyton
fungi, yeasts and nondermatophyte molds
Types of Onychomycosis
• Distal subungal onychomycosis
• White superficial onychomycosis( Leukonychia trichophytica):
An invasion of the toenail plate in the surface of the nail. Caused by T.mentagrophytes, species of Cephalosporium, and Aspergillus,and Fusarium oxysporum fungi. In the HIV positive population, commonly by T.rubrum
• Proximal subungal onychomycosis; may be an indicaton of HIV.( byT.rubrum and T. megninii)
• Candida onychomycosis. It produces destruction of the nail and massive nailbed hyperkeratosis and is seen in patients with chronic mucocutaneous candidiasis.
Onychomycosis, Cont….D/Dg
• Psoriasis
• Lichen planus
• Eczema
• Contact dermatitis
• Hyperkeratotic/( Norwegian) scabies
Onychmycosis Treatment
• Griseofulvin
• Terbinafine, for finger nails 250mg/day for 6-8 weeks, for toe nails 12-16 week
• Itraconazole, pulse therapy of 200 mg twice a day for 1 week of each month, for 2-3 months when treating finger nails, and for 3-4 months when treating toe nails
• Fluconazole, 150-300mg/once a week for 6-12 months
Onychomycosis, Cont….
Diagnosis
• Microscopic examination
• Culture
• Histopathologic examination with a
periodic acid –Schiff stain(PAS),41-93%
sensitive. More sensitive than either KOH
or culture
Onycho. Treatment cont….
• Presence of dermatophytoma,presenting as yellow
streaks within the nail, may be associated with a higher risk of failure
• Candida onychomycosis is always a sign of immunosuppression. Combinations of topical and systemic treatment can be used for synergistic effect.
• Molds are sensitive to ultraviolet(UV) and visible light
• Nystatin, topical amphotericin B lotion
Older agents such as gentian violet, castellani paint, boric acid
Oral candidiasis( Thrush)
• In the newborn may be acquired from contact with the vaginal tract of the mother
• In older children and adults , following antibiotic therapy it may also be a sign of immunosuppression
• Grayish-white membranous plaques with moist,reddish,and macerated base
• The papillae of the tongue may appear atrophic, with the surface smooth, glazed, and bright red.
• Saliva inhibits the growth of Candida, and a dry mouth predisposes to candidial growth.
Treatment of oral Candidiasis
• Infants : oral nystatin suspension
• Adults: A single dose of 150 mg.
fluconazole
• Immunocompromised adults:200 mg. is
the starting dose, or higher dose.
• Itraconazole,200mg./day for 5-10 days
• Terbinafine,250 mg./day
Perle’che( angular cheilitis)
• Characterized by maceration and transverse fissuring of the oral commissures.
• Soft pin-head sized papules may appear
• Usually bilateral
• Commonly related to C.albicans, but may also harbour coagulase-positive S.aureus and gram-negative bacteria
• Similar changes may occur in riboflavin deficency or other nutritional deficiency, and from drooling in persons with malocclusion caused by ill-fitting dentures, and old age when the upper lip overhangs the lower at the commissures.
• If the cause is C.albicans, anticandidal creams
Candidal vulvovaginitis
• C.albicans is a common inhabitant of vaginal tract. Overgrowth can cause severe pruritis,burning and discharge.
• Discharge varies from watery to thick and white or curd like.
• Predisposing factors:
pregnancy, diabetes, secondary to
therapy with broad-spectrum antibiotics
Candida vulvovaginitis,…Cont.
Treatment
• Oral fluconazole, 150 mg given once.
• In some patients with predisposing factor
longer courses of 150-200 mg/day or itraconazole, 200 mg/day for 5-10 days.
• Topical options: miconazole,nystatin,clotrimazole, and terconazole
Candidal Intertrigo
• Between the folds of the genitals; in groins
or armpits; between the buttocks; under
large pendulous breasts; under
overhanging abdominal folds; or in the
umbilicus
• Often ,tiny, superficial, white pustules
closely adjacent to the patches
Diaper Candidiasis
• Involvement of the folds and occurrence of many small erythematous desquamating “satellite” scattered along the edge of the larger macules.
• Eythematous macules progress to thin-walled pustules, which rupture, dry, and desquamate within a week or so.
• Usually widespread involving the trunk, neck, and head, and at times the palm and soles, including the nail folds.
• Oral cavity and diaper are spared.
• Systemic involvement may occur, and more common in infants who weigh<1500gm.
• Systemic involvement is suspected when respiratory distress or other laboratory or clinical signs of neonatal sepsis occur
Perianal Candidiasis
• May present as pruritis ani.
• Perianal dermatitis with erythema,oozing,
and maceration
• Satellite lesions may be present
Candidial paronychia
• Inflammation of the nail fold producing redness,
edema, and tenderness of the proximal nail
folds, and gradual thickening and brownish
discoloration of the nail plates.
• Acute paronychia is usually staphylococcal in
origin.
• Avoidance of irritants and wet work is essential.
• Treatment is anticandidial agents alone or in
combination with topical corticosteroid.
Erosio Interdigitalis
Blastomycetica
• An oval- shaped area of macerated white skin seen in the web b/n and extending onto the sides of the fingers.
• Nearly always the third web, between the middle and ring fingers. The moisture beneath the ring macerates the skin and predisposes to infection.
• On the feet, the fourth interspace that is most often involved.
Chronic Mucocutaneous
Candidiasis
• A chronic candidial infection of the
mucosal surfaces, skin, and nails.
• Onset , typically before age of six.
• Onset in adult life may herald the
occurrence of thymoma.
Chronic Mucocutaneous
Candidiasis, …cont.
• Either inherited or sporadic.
• Inherited type may be associated with endocrinopathy.
• Patients with this problem have a selective defect in immunity that leaves them vulnerable to candidiasis.
• The underlying defect is unknown.
• Control: systemic fluconazole, itraconazole,or ketoconazole
Candid
As in dermatophytosis, patients with
candidiasis may develop secondary id
reaction.
Dermatophytids
• “id” eruptions concomitantly on the trunk and extremities; vesicular, lichenoid, papulosquamous,or pustular.Rarely scarlatinform or morbilliform
• Fungus not demonstrable
• Erysepelas like dermatophytid is most commonly seen on the shin, usually with toe web tinea on the same side.
• As the fungal infection subsides involution of the dermatophytids.
Fungal Folliculitis( Majocchi
granuloma)
• Presents as a circumscribed , annular,
raised, crusty and boggy granuloma in
which the follicles are distended with viscid
purulent material.
• Most frequently on the shins or wrists.
Often in areas of occlusion, shaving or
when topical corticosteroid has been used
Tinea incognito
Atypical clinical lesions of tinea, usually
produced by treatment with a topical
corticosteroid or occasionally a calcineurin
inhibitor.
Tinea versicolor ( Pityriasis
versicolor) • Caused by Malassezia furfur. The yeast form of this
organism is classified as Pityrosporum orbiculare.
• As a yeast the organism is a normal follicular flora.
• It produces skin lesions when it grows in the hyphal phase.
• Hyper-or hypopigmented coalescing scaly macules on the trunk and upper arms.
• In some instances many follicular papules.
• Pink, atrophic, and trichome variants exist. May occur on the penis, pubis, scalp,and palms.
Tinea versicolor,….Cont.
Diagnosis • Scrapings of the scales
• Tape stripping of the lesions
• Microscopically, short, thick fungal hyphae and large number of variously sized spores( spaghetti and meat balls)
• Biopsy: a thick basket-weave stratum corneum with hyphae and spores.
• In the atrophic variant, epidermal colonization with hyphae and spores is accompanied by effacement of the rete ridges, subepidermal fibroplasia, pigment incontinence, and elastolysis
• Wood’s light examination accentuates pigment changes (yellow-green fluoresence of the lesions)
• Rarely culture
T. versicolor, cont…D/Dg.
• Seborrheic dermatitis
• Pityriasis rosea
• Pityriasis rubra pilaris
• Pityriasis alba
• Leprosy
• Syphilis
• Vitiligo
T. versicolor, Cont….
In the atrophic variant, parapsoriasis,
mycosis fungicides, anetoderma, lupus
erythematodes, or steroid atrophy
Treatment of T. versicolor
• Imidazole, triazole, selenium sulfide, ciclopirox olamine, zinc pyrithione, sulfur preparations, salicylic acid preparations, benzoyl peroxide
• Selenium sulfide, applied daily for a week, washed off after 10 minutes. Also as a single overnight application, repeated monthly as prophylaxis
• Ketoconazole, 400 mg., repeated monthly
• Itraconazole, 200 mg. once a day for 7 days, followed by a prophylactic treatment with 200 mg. twice a day on first day of a month.
• Fluconazole, 400 mg. once, and repeated at monthly intervals.
• Terbinafine is ineffective via the oral route, but effective topically.
Pityrosporium folliculitis
Criteria for diagnosis include:-
• Characteristic morphology,
• Demonstration of yellow-green wood’s
light flurosenceof the papules
• Demonstration of pityrosporum yeast in
smears or biopsies
• Prompt response to antifungal treatment