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Questions and Answers
What is the primary characteristic of superficial mycoses?
What causes Tinea Versicolor?
Which clinical manifestation is typical of Tinea Versicolor?
How does Tinea Nigra typically present on the skin?
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What characteristic is noted under microscopic examination for Tinea Versicolor?
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What common treatment is used for Tinea Versicolor?
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What is a notable factor that contributes to the overgrowth of Malassezia furfur in Tinea Versicolor?
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What treatment is mentioned for Tinea Nigra caused by Hortaea werneckii?
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What is the appearance of colonies produced by Tinea Nigra on culture?
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Which method is NOT recommended for treating Tinea Nigra?
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What is a characteristic clinical manifestation of White Piedra?
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How does Black Piedra appear microscopically when diagnosed with KOH?
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Which of the following is NOT a treatment option for White Piedra?
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What type of media do Trichosporon spp. grow rapidly on for lab diagnosis?
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What is one distinguishing feature of Black Piedra compared to other hair infections?
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Which of the following treatments is effective for both Black Piedra and Tinea Nigra?
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Study Notes
Superficial Mycoses
- Involve the outer layer of the skin or hair shafts
- Don't invade living tissue or elicit a cellular response
- Often asymptomatic and go unnoticed
Tinea Versicolor
- Caused by Malassezia furfur
- Characterized by patchy, discolored skin lesions
- Commonly known as "an-an"
- Lesions occur on smooth skin, most commonly on the face, chest, arms, and abdomen
- Lesions can be hyper- or hypopigmented
- Appear dry and chalky due to scaling
- Common in hot, humid, tropical climates
- Prevalent in corticosteroid therapy patients
Tinea Versicolor: Lab Diagnosis
- Microscopic examination of KOH-treated skin scrapings reveals budding yeasts and septate hyphae
- "Spaghetti and Meatball" appearance
- Requires lipids for growth in culture
- Colonies are cream-colored, moist, and smooth, fluoresce yellow under Wood's lamp
Tinea Versicolor: Treatment
- Aims to eliminate the organism from the skin
- Topical miconazole nitrate is effective
- Anti-dandruff shampoos can be used
Tinea Nigra
- Caused by Hortaea werneckii
- Presents with brown to black, nonscaly macules, mostly on palms and soles
- Characterized by dematiaceous growth of yeast and hyphae
Tinea Nigra: Lab Diagnosis
- Direct examination of KOH-treated skin scrapings reveals septate hyphae and budding cells
- Younger cultures exhibit budding blastoconidia, older cultures show hyphae with clustered blastoconidia
- Produces shiny, moist, yeast-like colonies that start brown and turn olive to greenish black on SDA
Tinea Nigra: Treatment
- Responds to keratolytics
- Daily application of Whitfield's ointment
- Tincture of iodine, 2% salicylic acid, or 3% sulfur can also be used
White Piedra
- Caused by Trichosporon spp. (T. ovoides, T. asteroides, T. cutaneum, T. inkin, T. asahaii)
- Characterized by soft, cream-colored mycelial mats around hair on the scalp, face, and pubic region
- Primarily affects hairs of the scalp, axillae, genitals, and facial hair like mustaches and beards
White Piedra: Lab Diagnosis
- Trichosporon spp. grow rapidly on primary fungal media, producing arthroconidia, hyphae, and blastoconidia
- Colonies are straw to cream-colored and yeast-like
- Vary in appearance, smooth or wrinkled, dry or moist, creamy or velvety
White Piedra: Treatment
- Shaving or cutting infected hair is often sufficient
- Topical fungicides like bichloride of mercury (1:200)
- Benzoic and salicylic acid combinations
- 3% sulfur ointments
- 2% formalin can be used
Black Piedra
- Caused by Piedraia hortae
- Occurs on hair of the scalp
- Characterized by hard, dark brown to black, gritty nodules firmly attached to the hair shaft
- Differentiate from nits of pediculosis and abnormal hair growth
Black Piedra: Lab Diagnosis
- Infected hairs placed in KOH reveal asci when nodules are crushed
- Thick-walled rhomboid cells containing ascospores are observed
- Grows slowly on Sabouraud dextrose agar at room temperature, forming brown, restricted colonies
Black Piedra: Treatment
- Shaving or cutting infected hair is often sufficient
- Topical fungicides like bichloride of mercury
- Benzoic acid/salicylic acid combinations
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Description
Explore the characteristics, diagnosis, and treatment of Tinea Versicolor, a common superficial mycosis. This quiz covers its symptoms, causative agent Malassezia furfur, and laboratory identification methods. Learn about effective treatment options and the conditions that predispose individuals to this skin condition.
