Yeast infection

Yeast Infection

By
Dr.Alaa Al-sahlany
Nov. 11, 2018

Pityriasis versicolor

Caused by malassaezia furfur and M. globosa,
are part of the normal follicular flora

Present with multiple hyperpigmentd or hypopigmented patches with fine(fluffy or furfuraceous) scale. Demonstration of this associated scale may require scratching or stretching the skin surface

Fluffy

Furfuraceous (bran-like)

Decreased pigmentation may be secondary to the inhibitory effects of dicarboxylic acids on melanocytes (these acids result from metabolism of surface lipids by the yeast) or decreased tanning, due to the ability of the fungus to filter sunlight(work as a sunscreen).

More common during the summer months owing to high temperature and humidity

Usually asymptomatic

Malassezia is lipophilic: therefore,(1) seborrheic regions, in particular the upper trunk and shoulders, are the favored sites of involvement and (2) adolescents are frequently affected.


Malassezia is dimorphic i.e. grow both as a yeast and hyphae

Dx: KOH examination of scale scraping which shows “Spaghetti and meatballs” which are hyphae and spores, respectively

Spaghetti and meatballs

Dermatophyte hyphae

Treatment

Topical treatment : selenium sulfide or ketaocoazole shampoo applied daily for a week. Others: Other imidazoles, zinc pyrithion, sulfur, and benzyl peroxide

Systemic : itraconazole (200 mg/day) for a week, fluconazole (300 mg) weekly for two weeks

Candidiasis(Candidosis or Moniliasis)

C. albicans is a common inhabitant of the gastrointestinal and genitourinary tracts, and skin


C. albicans is an opportunistic organism. Under the right conditions e.g. decreased immunity, moisture and decreased competing flora, It can cause lesions of the skin, nails, and mucous membranes

Predisposing factors:

Diabetes mellitus
Xerostomia(saliva inhibit growth of candida)
Occlusion e.g. under adhesive plaster
Hyperhidrosis
Use of corticosteroids and broad- spectrum antibiotics
Immunosuppression, including HIV infection

Diagnosis

Microscopical KOH examination show budding yeast and pseudohyphae in stratum corneum and superficial mucosa

Histological exam with PAS stain

Sabouraud culture . It takes about 4 days to grow colonies

Oral candidiasis (Thrush)
The mucous membrane of the mouth may be involved in healthy infant


In the newborn the infection may be acquired from contact with the vaginal tract of the mother

(1)Pseudomembranous Candidiasis (Thrush):

White-to-creamy plaques on any mucosal surface. Removal with a dry gauze pad leaves an ery- thematous mucosal surface. Can involve dorsum of tongue, buccal mucosa, hard/soft palate, pharynx, esophagus.

(2) Erythematous (Atrophic) Candidiasis: Smooth, red, atrophic patches(atrophic papillae)

(3) Hyperplastic candidiasis: white plaques that cannot be wiped off.

It is often the first manifestation of AIDS.

Rx:

Topical:oral nystatin suspension or clotrimazole troches that dissolve in the mouth
Systemic: fluconazole and itraconazole.

Angular Cheilitis(Perleche)

White plaques with slight erythema of the mucous membrane at the angles of mouth. Maceration and fissures may ensue

Is commonly related to C. albicans, but may be caused by coagulase­positive S. aureus and Gram­negative bacteria. Similar changes may nutritional deficiency e.g. riboflavin and iron.

Drooling in persons with malocclusion caused by ill­ fitting denture or overlap of angles of mouth in edentulous elderly are predisposing factors.

RX: Topical anticandidal

Candidal vulvovaginitis

Overgrowth of candida can cause the labia to be erythematous, moist.

There might be a pruritus, burning and curd-like discharge

Pregnancy, high-dose estrogen and long­term tamoxifen treatment are a predisposing factors

About 20% of asymptomatic women are vaginal %carriers. During pregnancy, this rises to 40

Candidiasis can be sexually transmitted and this is probably most important in recurrent infections(more than 3 episodes per year)

Rx:vaginal suppositories containing nystatin or imidazole. Single-dose oral fluconazole is an alternative

Balanitis and Balanoposthitis

Balanitis is more common in the uncircumcised man


The skin is erythematous and glazed with pustules and erosions

Rx: topical anticandidal agents or single dose oral fluconazole. Treatment of sexual partner is essential

Candidal intertrigo

Can involve groins or armpits; intergluteal cleft; under large breasts; under overhanging abdominal folds; or in the umbilicus.

Red moist patches surrounded by a fringe of macerated epidermis (“collarette” scale).

Tiny pustules and papules are observed closely adjacent to the patches, termed “satellite or daughter” lesions

Rx: Topical anticandidal preparations are usually effective. Oral anti-candidal agents are alternative

Diaper candidiasis

Differentiated from contact dermatitis by:

(1) Involvement of the folds
(2) Occurrence of many small erythematous “satellite” or “daughter” lesions scattered along the edges of the larger patch(es)

Rx: Topical anticandidal agents are effective. Recurrent cases may be associated with gut colonization and need Rx with oral nystatin

Perianal candidiasis

May present as a pruritus ani

Pruritus and burning can be very severe

Characterized by erythema, maceration and less commonly fissure

Rx: topical anticandidal agents are effective. Oral antifungals are alternative

Candidal paronychia

Redness, edema, and tenderness of the proximal and lateral nail folds

Usually the fingernails are affected more than toenails

Patients commonly have an atopic background


Frequently seen in diabetics and those who work

Two types:

Acute: usually caused by staph. aureus

Chronic: multifactorial i.e. Irritant dermatitis and candidiasis

Rx: Avoidance of chronic exposure to water and irritants and bringing the diabetes under control in addition to topical steroids in combination with topical anti-candidal agents

Acute paronychia

Chronic paronychia

Erosio interdigitalis blastomycetica

Oval­ shaped area of macerated white skin associated with fissures and raw red skin at the center on the web between fingers

Nearly always between the middle and ring fingers

Moisture beneath the ring predispose to infection

On the feet it is the fourth web space that is most often involved

Clinically, this may be indistinguishable from tinea pedis

Rx: drying and topical anticandidal agents

Antifungals

Comment

Spectrum of action
Antifungal agent
In general, the longest course of treatment is for tinea unguium followed by tinea capitis followed by other types of dermatophytosis

Griseofulvin is the first choice for treatment of tinea capitis (4-12 weeks course)

Imidazoles and allylamines are the first choice for treatment of tinea unguium but griseofulvin is not used for tinea unguium because it require a long course (4-6 months to one year)
Dermatophytes, Candida and Pityrosporum
• Imidazoles e.g. ketoconazole, itraconazole, fluconazole, clotrimazole:

Dermatophytes

• Allylamines e.g. terbinafin

Candida only

• Polyenes e.g. amphotericin B and nystatin

Dermatophytes only

Griseofulvin


Candidid(id reaction)
They are much less common than the reactions seen with dermatophytosis.