Econazole 1% shampoo versus selenium in the treatment of tinea versicolor: a single-blind randomized clinical study

Pityriasis versicolor: quality of studies

OBJECTIVE

To evaluate the quality of the published literature on the treatment of pityriasis versicolor and to compare this evaluation with the number of times the work has been cited.

METHODS

A search was performed using MEDLINE (1966-2002) to find publications evaluating the treatment of pityriasis versicolor. Two reviewers evaluated each clinical trial according to a list of pre-determined criteria including randomization and blinding, prior sample size calculation, treatment regimen clearly explained, and well-defined efficacy parameters. A maximum score of 20 could be attained by each publication. A citation count was performed using the ISI Web of Science Database (http://www.isinet.com/isi/products/citation/wos/).

RESULTS

A total of 94 studies were included in this analysis of quality. Studies with a score of 8 or more were considered to be high quality, and 61 studies were rated as high-quality studies (65%). There was no significant correlation between paper quality and citation count.

CONCLUSION

It is important for investigators and clinicians to be aware of the design of a high-quality protocol, since such high-quality studies are more likely to reflect accurate efficacy rates. Also, it is important for the information on the design and conduct of the trial to be conveyed to the reader so that a meaningful comparison between the studies can be made.

Pityriasis versicolor: a review of pharmacological treatment options

Pityriasis versicolor is a common disorder of the skin, which is characterised by scaly hypo- or hyperpigmented lesions on the body. The lipophilic yeast, Malassezia, is considered to be the aetiological agent of this disease. A number of treatment options, both topical and systemic, have been shown to be effective. A critical evaluation of treatment options is presented.

Pityriasis versicolor

Pityriasis versicolor is a mild or chronic condition characterized by scaly hypopigmented or hyperpigmented lesions usually affecting the trunk. The lesions vary depending on tropical or temperate climates. The disease seems to occur mainly at adolescence when the sebaceous glands are more active. Malassezia yeasts have been implicated in the pathogenesis of this disease. The mycelial form of the fungus has been suggested to be the cause of lesions. Antifungal preparations have been used to treat the initial presentation effectively, although in a proportion of patients the disease tends to reoccur. They are available in a wide range of formulations and have been shown to be safe.

Pityriasis versicolor

Pityriasis versicolor is a common superficial fungal infection of the skin. It is caused by Malassezia spp., which are normal human saprophytes. Under certain conditions, both exogenous and endogenous, the fungus can convert from a yeast to a pathogenic mycelial form. This alteration results in mild inflammation of the skin, and in characteristic clinical and histological changes. The taxonomy of Malassezia spp. has recently been modified to include six obligatorily lipophilic species, all of which can be found on human skin, plus one non-obligatorily lipophilic species, which only rarely colonizes human hosts.

LEARNING OBJECTIVES

At the conclusion of this learning activity, participants should be aware of the role of Malassezia in the development of pityriasis versicolor, the clinical and histological changes arising from this dermatosis, and the diagnosis and treatment of this disorder.