Tinea Versicolor

Welcome to PT 635 Pathophysiology of Complex Patient Problems This is a wiki created by and for the students in the School of Physical Therapy at Bellarmine University in Louisville KY. Please do not edit unless you are involved in this project, but please come back in the near future to check out new information!!

Original Editors - Students from Bellarmine University's Pathophysiology of Complex Patient Problems project.

Lead Editors - Your name will be added here if you are a lead editor on this page.  Read more.

Definition/Description

Pityriasis or tinea versicolor is a common chronic superficial fungal skin infection of the upper trunk, neck, and upper arms caused by the organism Mallassezia furfur. 

Prevalence

It is frequently seen in tropical regions, with prevalence as high as 40%; it is also common in temperate areas, representing up to 3% of patients seen by dermatologists during the summer months. Children age 0-15 years had a 17.8% prevalence of pathogens of the genus Malassezia in the skin. The highest prevalence of colonisation was 23.3% in infants age 0-18 months and 26.7% in 11-15 year-olds.

The species of Malassezia that are involved are Mglobosa (77%-90% of affected patients in Spain, 55% in Japan, 25% in Canada), M. sympodialis (32%-42% in Spain, 9% in Japan, 59% in Canada). and M. furfur (11% in Canada).

US National Health Survey data from 1971-1974 showed a prevalence of 0.8% among people 1-74 years old in the United States. 

Characteristics/Clinical Presentation

Symptoms Include:

• Numerous spots and patches appear on the neck, upper back, and shoulder.
• The spots are covered by a fine scale.
• The spots vary in size.
• In summer, the spots are light and don't tan like the normal skin.
• In winter, as normal skin tone fades, the spots look darker than normal skin.

"Patients with tinea versicolor usually have many irregularly shaped slightly scaling macules and patches, generally covering large areas of the body and seperated by skip regions of normal skin. The macules and patches are yellowish-brown, pale yellow, or dark-brown, occasionally reddish or pinkish, appearing hypopigmented or heyperpigmented." Individual patches usually display a fine scale where the surface can appear to be smooth and shiny or dull.  "Affected areas include the chest, back, neck, and face; however, patches are usually most abundant on the back. Facial patches are more common in children than adults."

"Patients usually present in the late spring or summer in temperate zones and may state that this is the rash they get every summer."

Associated Co-morbidities

Both dermatologic and non-dermatologic comorbidities exist with tinea versicolor. "Common comorbid dermatologic conditions included: acne, dermatitis, melanoma, dyschromia, benign neoplasm of skin, seborrheic dermatitis, psoriasis, and dermatophyte infection. Common non-dermatologic conditions included: injury to blood vessels, elective surgery, hypertension, gastroenteritis, upper respiratory tract infection, multiple sclerosis, and HIV infection."

Medications

add text here

Diagnostic Tests/Lab Tests/Lab Values

Although diagnosis of tinea versicolor can be made based on appearance alone, there are several diagnostic tests available to make a definitive diagnosis. The test that has proven to be most useful is a "potassium hydroxide preparation of exfoliated skin cells from the tinea versicolor lesions. The affected skin is gently scraped with a blade or glass slide to collect a sample of scale on a microscope slide, but transparent tape can also be used to strip off the scales. Treatment of the specimen with potassium hydroxide will reveal a characteristic "spaghetti and meatballs" appearance upon microscopic examination."  

If there is doubt of the diagnosis the skin scraping can be sent for fungal culture. A skin biopsy may also be performed. This will show short hyphae and spores in the stratum corneum. Staining they biopsy with periodic acid-Schiff or methanamine silver has been proven to be helpful in the diagnosis of tinea versicolor. 

"A Wood's light-a portable quartz lamp emitting low frequency UV light at 365 nm-is used to confirm the diagnosis and detect subclinical patches of fungi." This diagnostic method has only been positive in fewer than half of cases.

Causes

Tinea versicolor is not a contagious disease and is not due to poor hygiene. "The infection results from a change to the mycelial state of dimorphic lipophilic yeasts of the genus Malassezia, which colonise the stratum corneum and are typical skin flora. Yeasts of this genus are found in regions of the body that are rich in sebaceous lipids, such as the head, trunk, and upper back."

"Malassezia spp are present in 90-100% of people as typical flora; frequency and density of the pathogens are related to patient's age, regional sebaceous glands, and genital secretions", causing these species to be distributed unevenly on the healthy human body. "In both their normal and pathological forms, these pathogens reside within the stratum corneum and hair follicles, where free fatty acids and tryglycerides from sebum and keratinised epidermis might be altered in some way to provide a desirable host environment to primary or recurrent infection." 

Systemic Involvement

add text here

Medical Management (current best evidence)

add text here

Physical Therapy Management (current best evidence)

add text here

Alternative/Holistic Management (current best evidence)

add text here

Differential Diagnosis

• pityriasis rosea
• vitiligo
• post-inflammatory hypo or hyperpigmentation
• hypopigmented mycosis fungoides
• erythrasma
• pityriasis alba
• seborrheic dermatitis

Case Reports

add links to case studies here (case studies should be added on new pages using the case study template)

Recent Related Research (from Pubmed)

see tutorial on Adding PubMed Feed

References

see adding references tutorial.