- Superficial fungal infection that interferes with normal skin pigmentation resulting in macules or patches that are hypopigmented, tan, brown, or salmon-colored. Tinea versicolor is usually well-demarcated, finely scaling, occurring primarily on the trunk and proximal upper extremities. Tinea versicolor is not a dermatophyte infection. It is caused by lipophilic (fat/oil-loving) Malassezia yeast organisms that normally inhabit the skin.
- System(s) affected: skin/exocrine
- Synonym(s): pityriasis versicolor
- Common, occurs worldwide, especially in tropical climates
- Predominant age: adolescents and young adults
- Predominant sex: male = female
Skin eruptions usually occur after puberty, when sebaceous glands are more active. However, tinea versicolor can also be seen in children, especially in tropical climates; facial lesions are more common in children.
Not common in the geriatric population
Prevalence can reach up to 50%, especially in warm climates.
Etiology and Pathophysiology
The inhibition of pigment synthesis in epidermal melanocytes leads to hypopigmented skin patches. In the hyperpigmented type, melanosomes increase in size resulting in brown or darker patches of skin of varying shades.
- Tinea versicolor is caused by saprophytic yeast: Pityrosporum orbiculare (also known as Plasmodium ovale, Malassezia furfur, or Malassezia ovalis), which is a known colonizer of all humans.
- Development of clinical disease is associated with transformation of Malassezia from yeast cells to pathogenic mycelial form. Several endogenous (host) and exogenous/external factors may play a role in the transformation to active disease.
- Tinea versicolor is not linked to poor hygiene.
- Tinea versicolor is generally not contagious.
Genetic predisposition may exist.
- Hot, humid weather
- Use of topical skin oils
- HIV infection/immunosuppression
- High cortisol levels (Cushing syndrome/disease, prolonged steroid administration)
- Oral contraceptives
- Prophylaxis can be used in warm summer months and prior to tanning season in people with frequent recurrences.
- Avoiding skin oils may help.
- Tinea versicolor is not contagious.
There's more to see -- the rest of this topic is available only to subscribers.