FUNGAL INFECTION-TINEA Flashcards
Superficial fungal infections of the skin/scalp; various forms of dermatophytosis;
Tinea
Infection of crural fold and gluteal cleft
Tinea Cruris
Infection involving the face, trunk, and/or extremities;
often presents with ring-shaped lesions, hence the misnomer ringworm
Tinea Corporis
Infection of the scalp and hair; affected areas of the scalp can show characteristic black dots resulting from broken hairs
Tinea Capitis
(a) Scaling, round or oval pruritic plaques characterized by a sharply defined annular pattern with peripheral activity and central clearing (ring-shaped lesions).
(b) Papules and occasionally pustules/vesicles present at border and, less commonly, in center.
(c) Pruritus may or may not be present.
Tinea Corporis
Tinea Corporis
Treatment
(a) Topical
1) Superficial lesions respond to antifungal creams.
2) Clotrimazole, Miconazole or Terbinafine applied BID for a minimum of 2 weeks.
3) Continue treatment for at least 1 week after resolution of the infection.
4) Extensive lesions or those with red papules require oral therapy.
(b) Oral
1) Griseofulvin (ultra-microsize) 250 po mg QD x 2 weeks or Fluconazole 150 mg once a week for 3-4 weeks.
2) Secondary bacterial infections are treated with oral antibiotics.
3) A short course of prednisone may be considered for highly inflamed lesions to minimize scarring
Tinea Corporis
Differential Diagnosis
(a) Nummular eczema
(b) Pityriasis Rosea
(c) Psoriasis
(d) Secondary Syphilis
Tinea Corporis
Labs/Studies/Imaging
(a) KOH prep or fungal culture
(b) Woods lamp
Tinea Corporis
Disposition
Full duty
Tinea Corporis
Complications
Extension of disease down to the hair follicles
(a) Well-marginated, erythematous, halfmoon-shaped plaques (arcuate) in crural (groin) folds that spread to medial thighs; advancing border is well defined, often with fine scaling and sometimes vesicular eruptions.
(b) Lesions are usually bilateral and do not include scrotum/penis (unlike with Candida infections).
(c) May migrate to perineum, perianal area, and gluteal cleft and onto the buttocks in chronic/progressive cases.
(d) The area may be hyperpigmented on resolution
Tinea Cruris
Tinea Cruris
Treatment
(a) First-Line:
1) Topical antifungal cream (terbinafine, miconazole, clotrimazole, ketoconazole) applied 2 times a day for 10 to 14 days.
2) Absorbent powders (+/- antifungals) help to control moisture and prevent re-infection.
(b) Refractory, inflammatory or widespread infections:
1) Itraconazole 200 mg orally once a day or terbinafine 250 mg orally once a day for 3 to 6 weeks may be needed in patients who have.
2) Resume topical antifungal cream once symptoms are controlled
Tinea Cruris
Differential Diagnosis
(a) Intertrigo
(b) Candidiasis
(c) Erythrasma - fluoresces red under Wood’s lamp exam
Tinea Cruris
Disposition
Full Duty generally, but light duty depending on symptoms and severity
Tinea Cruris
Complications
Secondary bacterial infection
(a) Superficial infection in the interdigital web and soles of the feet caused by dermatophytes
(b) Most common dermatophyte infection encountered in clinical practice; contagious
(c) Often accompanied by tinea manuum, tinea unguium, and tinea cruris
(d) Common in males, uncommon in females
(e) Common co-factor in lower leg cellulitis
Tinea Pedis
Tinea Pedis
Presentation
(a) May progress to fissuring or maceration in toe web spaces.
(b) itching, burning, and stinging of interdigital webs and plantar surfaces. Pain may indicate secondary infection.
(c) asymptomatic scaling.
(d) classic “ringworm” pattern, found in toe webs/soles.
(e) Wood lamp exam will not fluoresce
Tinea Pedis
Treatment
(a) Open-toed sandals.
(b) shower shoes.
(c) Dry between toes after showering and frequent sock changing.
(d) Absorbent, non-synthetic socks preferred (Cotton).
(e) Antifungal powders.
(f) Recurrence is prevented by wearing wider shoes and expanding the web space.
(g) Powders are used to absorb excess moisture
(h) Topical Treatment
1) Topical medications applied BID for 2-4 weeks. (Clotrimazole, Miconazole, Terbinafine)
(i) Oral Treatment
1) For extensive/acute infections consider oral antifungals. May be started in combination with topical antifungal agents.
a) Lamisil
b) Sporanox
c) Fluconazole
2) Secondary bacterial infection is treated with oral antibiotics (common in heavily macerated lesions).
(a) Caused by Pityrosporum orbiculare, which is part of the normal skin flora.
(b) Organism is nourished by sebum; converts from yeast form to mycelial form and causes the disorder.
(c) Excess heat and humidity predispose to infection
Not linked to poor hygiene
Tinea Versicolor
Tinea Versicolor
Presentation
(a) Velvety tan, pink or white macules that do not tan.
(b) Color is uniform in each person but may vary between people.
(c) Fine scales that are not visible but are seen by scraping the lesion.
(d) Central upper back, chest, and proximal arms (same areas as the highest concentration of sebum).
(e) Typically asymptomatic, but a few patients note itching when overheated.
(f) Appearance is often the patient’s major concern
Tinea Versicolor
Labs/Studies/Imaging
(a) Positive KOH; fungal culture is not useful
(b) Wood’s lamp shows hypo-pigmented areas of infection.
(c) Wood’s lamp will show faint yellow-green fluorescence/pigment changes determine extent of the disease
Tinea Versicolor
Differential Diagnosis
(a) Vitiligo
(b) Pityriasis Rosacea
Tinea Versicolor
Disposition
Disposition
Tinea Versicolor
Complications
Relapses are common without any complications.
Tinea Versicolor
Treatment
(a) Topical
1) Topical treatment is indicated for limited disease.
2) Selenium Sulfide 2.5% applied from neck to waist wash off after 515 minutes, repeat daily x 7 days. Repeat weekly x 1 month, then monthly for maintenance.
3) Ketoconazole 2% shampoo chest and back, wash off after 5 minutes. Repeat weekly.
(b) Oral
1) Oral treatment is used for patients with extensive disease and those who do not respond to topical treatment.
2) Cure rates may be greater than 90%.
a) Ketoconazole 400 mg in a single dose with exercise to point of sweating after ingestion. Single dose is not always effective.
b) Fluconazole 300 mg (2 capsules weekly x 2 weeks) has similar efficacy.
3) Oral Terbinafine is not effective for this condition.
