tinea barbae fitza

8/12/2019 Tinea Barbae Fitza

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TINEA BARBAE

EPIDEMIOLOGY.

Tinea barbae, as its name would imply, occurs predominantly in males. The

incidence of tinea barbae has decreased as improved sanitation has reduced

transmission by contaminated barbers razors. Direct exposure to cattle,

horses, or dogs is now the more common mode of acquisition, and this

accounts for a shift in prevalence toward farmers or ranchers in rural settings.

ETIOLOGY.

Tinea barbae is most commonly caused by the zoophilic strains of T.

interdigitale (former T. mentagrophytes var. mentagrophytes), T. verrucosum,

and less commonly M. canis. Among the anthropophilic organisms, T.

schoenleinii, T. violaceum and certain strains of T. rubrum (former T. megninii),

cause tinea barbae in endemic areas.42

CLINICAL FINDINGS.Tinea barbae affects the face unilaterally and involves the beard area more

often than the moustache or upper lip. Two forms exist.

Superficial Type.

Caused by anthropophiles such as T. violaceum, this form of tinea barbae is

less inflammatory and resembles tinea corporis or bacterial folliculitis. The

active border shows perifollicular papules and pustules accompanied by mild

erythema (Fig. 188- 8A). Alopecia, if present, is reversible.

Inflammatory Type.


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Usually caused by T. interdigitale (zoophilic strains) or T. verrucosum,

inflammatory tinea barbae is the most common clinical presentation. It

presents analogously to kerion formation in tinea capitis with boggy-crusted

plaques and a seropurulent discharge (Fig. 188-8B). Hairs are lusterless,

brittle, and easily epilated to demonstrate a purulent mass around the root.

Perifollicular pustules may coalesce and eventuate in abscess-like collections

of pus, sinus tracts, and scarring alopecia.

DIFFERENTIAL DIAGNOSIS OF TINEA BARBAE

Most Likely

Bacterial folliculitis (sycosis vulgaris), pseudofolliculitis barbae, acne vulgaris,

rosacea, contact dermatitis, perioral dermatitis, candidal folliculitis

Rule Out

Herpes simplex, halogenoderma

LABORATORY TESTS AND HISTOPATHOLOGY

Laboratory Test Method Function Findings

Potassium hydroxide

preparation

Scales from the advancing border, subungual

debris, or affected hair removed and place

on a glass slide. KOH 10% dropeed on

specimen and covered with a cover slip. The

undersurface of the glass slide may be gently

heated with a low-lit flame.

KOH solution and gentle

heating softens keratin

and highlights the

dermatophyte.

Ow narrow septated an

brancing hyphae

Culture Sabouroud medium (4% peptone, 1%

glucose, agar, water)

Facilities growth of

dermatophyte

Microscopic morpgolog

of microconidia and

macroconidia, along

with culture features

including surface


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topography and

pigmentation

Modified Sabouraud medium (addition of

chloramphenicol, cycloheximide, and

gentamicin)

Facilities growth of

dermatophytes and

inhibits growth of non-candida albicans,

Cryptococcus, prototheca

species, P. werneckii,

scytalidium species,

ochroconis gallopava

Characterization of

fungal colonies.

Common colonies arecharacterized in table

188-5.

Dermatophyte test

medium

Scales from advancing border, subungual

debris or affected hair embedded in the

medium.

Medium contains the pH

indicator phenol red.

Dermatophytes utilize

proteins resulting in

excess ammonium ion and

an alkaline environment.

Incubation at room

terperature for 5-14

days results in change in

color of medium from

yellow to bright red in

presence of a

dermatophyte.

Histolopathology

special stains: period

acid-Schiff and

Grocotts

methenamine silver

Tissue may be obtained by skin or nail

biopsy techniques

Stains fungal cell wall

detect fungal elements in

tisuue sections

Pink (PAS) or black

(GMS) fungal elements

noted in the stratum

corneum

TERAPHY

Like tinea capitis, an oral antifungal is usually necessary in the treatment of

tinea barbae. Ultramicronized griseofulvin 500 mg twice daily for 6 weeks,

terbinafine 250 mg daily for 24 weeks, itraconazole 200 mg daily for 24

weeks, and fluconazole 200 mg daily for 46 weeks are regimens that have

been used effectively. Systemic glucocorticoids used for the first week of

therapy are helpful in cases with severe inflammation.


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Disease Topical treatment Systemic treatment

Tinea barbae Only as adjuvant topical

antifungal

Griseovulvin 1gr/day (6 weeks)

Terbinafine 250mg/day (2-4 weeks)

Itraconazole 200mg/day (2-4 weeks)

Fluconazole 200mg/day (4-6 weeks)

GRISEOFULVIN.

Griseofulvin along with terbinafine in patients older than 4 years are systemic

treatments for tinea capitis approved by the US Food and Drug

Administration. The previously recommended pediatric dosage was 1020

mg/kg/day in divided doses for 68 weeks taken with a fatty meal to facilitate

absorption.33 However, high failure rates with this regimen resulted in the

current dosage recommendation of griseofulvin 2025 mg/kg/day of the

microsize form, and 15 mg/kg/day in divided doses of the ultramicrosize form

for 8 weeks.68 Although the current recommendation is not based on

outcomes of controlled trials, the collective clinical experience suggests its

high therapeutic efficacy. Disadvantages of griseofulvin include poor

compliance related to length of treatment and its bitter taste in liquid form.

Common side effects include photosensitivity, headache, and gastrointestinal

upset.69 Griseofulvin also is a potent inducer of cytochrome P450 enzymes.

TERBINAFINE.Doses of 36 mg/kg/day of terbinafine can cure Trichophyton tinea capitis in

24 weeks; however, 48 weeks of treatment may be required for eradication

of Microsporum.68 Two randomized trials confirmed the increased efficacy of


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terbinafine (58 mg/kg/day) in the treatment of T. tonsurans infection with

significantly higher cure rates compared to lower dose griseofulvin (1020

mg/kg/day). However, even at this lower dose range, griseofulvin showed

significantly higher cure rates for M. canis infections.70 Further, it is not clear

that terbinafine (58 mg/kg/day) has a therapeutic advantage in curing tinea

capitis over the higher dose regimen of griseofulvin (2025 mg/kg/day).

Terbinafine may cause gastrointestinal upset. As with itraconazole, there are

reports of liver failure in patients using terbinafine. Terbinafine has an

inhibitory effect on the CYP 2D6 subset of the cytochrome P450 system. While

fewer medications are metabolized through this CYP 2D6 subset as than

through the CYP 3A4 subset inhibited by itraconazole and ketoconazole,

notable interactions still exist with -blockers and tricyclic antidepressants.

ITRACONAZOLE.

At doses of 5 mg/kg/day for 24 weeks, itraconazole effectively eradicates

tinea capitis caused by either Microsporum or Trichophyton.68 Pulse therapy

at 5 mg/kg/day for 1 week out of each month for one to three cycles is also

effective. Possible adverse effects of itraconazole include gastrointestinal

upset, diarrhea with the liquid formulation, and peripheral edema, especially

when used in conjunction with calcium channel blockers. Itraconazole is

better absorbed in the presence of food, which results in secretion of gastric

acid and lower gastric pH. On the contrary, antacids such as H2 blockers may

decrease the absorption of itraconazole by increasing the gastric pH. Like with

fluconazole, hepatotoxicity with itraconazole occurs at lower rates than with

ketoconazole.35 Itraconazole has also rarely been linked to congestive heart


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failure. Itraconazole is an inhibitor of the CYP 3A4 subset of cytochrome P450

system.

FLUCONAZOLE.

Available as both tablets and a pleasant-tasting liquid, fluconazole at doses of

6 mg/kg/day for 20 days is effective in curing tinea capitis.68 Alternatively,

fluconazole can be administered as a pulse, once weekly, regimen with 6

mg/kg/day for 812 weeks.71 Absorption of fluconazole is not affected by

gastric pH, and gastrointestinal side effects are less common. Hepatitis has

been reported but it occurs less frequently than with ketoconazole.35

Fluconazole is a potent inhibitor of cytochrome P450 enzymes, in particular

CYP 2C9 and 2C19. Since most medications metabolized by the cytochrome

P450 system are through the CYP 3A4 subset, fluconazole has less potential to

interact with medications than other systemic imidazoles.

ADJUVANT THERAPY.Selenium sulfide (1% and 2.5%), zinc pyrithione (1% and 2%), povidone

iodine (2.5%), and ketoconazole (2%) are shampoo preparations that help

eradicate dermatophytes from the scalp of children. Adjunctive use of these

shampoos is recommended 24 times weekly for 24 weeks.72 The use of

ketoconazole 2% shampoo or selenium sulfide 2.5% three times weekly by all

household members also reduces transmission by decreasing the shedding of

spores.69 Oral glucocorticoids may reduce the incidence of scarring

associated with markedly inflammatory varieties of tinea capitis. Although

there is no consistent evidence for improved cure rates with use of oral

glucocorticoids, they appear to relieve pain


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and swelling associated with infections. The usual regimen prednisone is 12

mg/kg each morning during the first week of

therapy.

TOPICAL THERAPY.

In those patients with distal nail involvement and/or contraindication for

systemic treatment, topical therapy should be considered. Ciclopirox 8%

lacquer applied daily for 48 weeks achieved mycologic cure in 29%36% of

cases and clear nails (clinical cure) in 7% of mild to moderate cases of

onychomycosis caused by dermatophytes.77 Despite its much lower efficacy

compared with oral antifungal agents, use of topical ciclopirox avoids risk of

drug interactions. Amorolfine 5% applied twice weekly is another agent

specifically prepared for use as a nail lacquer. It is the first member of a new

class of antifungal drugs, the morpholine derivatives, which show activity

against yeasts, dermatophytes and molds that cause onychomycosis.

Amorolfine may have higher mycologic cure rates (38%54% after 6 months

of treatment) compared to ciclopirox lacquer; however, prospective

controlled trials validating a significant difference are needed.78

SYSTEMIC THERAPY.

An oral antifungal is required for onychomycosis involving the matrix area, or

when a shorter treatment regimen or higher chance for clearance or cure isdesired. Selection of the antifungal agent should be based primarily on the

causative organism, the potential adverse effects, and the risk of drug

interactions in any particular patient. Terbinafine is fungistatic and fungicidal

against dermatophytes,Aspergillus, and less so against Scopulariopsis.


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Terbinafine is not recommended for candida onychomycosis since it

demonstrates variable efficacy against Candida species. A course of

terbinafine 250 mg daily for 6 weeks is effective for most fingernail infections,

while a minimum 12-week course1216 is required for toenail infections.

Most adverse effects are gastrointestinal such as diarrhea, nausea, taste

disturbance, and elevation of liver enzymes. Evidence suggests that a 3-month

continuous regimen of terbinafine is the most effective oral treatment for

onychomycosis of the toenails available today.79 Clinical cure rates among

different studies are approximately 50%, although the success rate is lower in

patients over 65 years.80 Itraconazole is fungistatic against dermatophytes,

nondermatophyte molds and yeasts. Safe and effective schedules include

pulse dosing with itraconazole 400 mg daily for 1 week per month or a

continuous dose of 200 mg daily, both of which require 2 months or 2 pulses

of treatment for fingernails and at least 3 months or 3 pulses for toenails.73

Itraconazole is dosed by weight in children at 5 mg/kg/day.81 Elevated liver

enzymes occur in 0.3%5% of patients during therapy and return to normalwithin 12 weeks of discontinuation. Although itraconazole has a broader

spectrum of activity than terbinafine, studies have shown a significantly lower

rate of cure (about 25% vs. 50%) and higher relapse rate (about 50% vs.

20%) with itraconazole compared with terbinafine.82,83 Fluconazole is

fungistatic against dermatophytes, some nondermatophyte molds, and

Candida. The usual regimen for fluconazole is 150

300 mg once weekly for 3

12 months.73 Griseofulvin is no longer considered standard treatment for

onychomycosis because of its prolonged treatment course, potential for

adverse effects and drug interactions, and its relatively low cure rates.


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Combination therapy regimens may have a higher clearance rate than either

oral or topical treatments alone. Oral terbinafine combined with amorolfine

nail lacquer was shown to result in clinical cure and negative mycology in

59% of patients compared to 45% of patients treated with oral terbinafine

alone.84 However, another study failed to show any additional benefit of

combining oral terbinafine with ciclopirox 8% solution.85

In vitro fungicidal activity demonstrated by thymol, camphor, menthol, and oil

of Eucalyptus citriodora86,87 offers the potential for additional therapeutic

strategies to treat onychomycosis. Thymol 4% prepared in ethanol may beused as drops

applied to the nail plate and hyponychium. The application to nails of

commercially available topical preparations with thymol, such as Vicks

VapoRub, has anecdotally led to success. Final options for refractory cases

include surgical avulsion or chemical removal of the nail with 40% urea

compounds in combination with topical or oral antifungals.

tinea barbae fitza

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