Swab technique as effective as scrape method for diagnosing pediatric tinea capitis

Efficacy of the cotton swab-culture method for diagnosing tinea capitis in pediatric patients is indistinguishable to the scrape-culture method, according to a prospective study published in the Journal of the American Academy of Dermatology.

“The cotton swab-culture technique may be an efficient and effective way to obtain samples from pediatric patients in whom tinea capitis is suspected,” Michelle Le, MD, of the division of allergy, immunology and dermatology at McGill University in Montreal, and colleagues wrote. “To this date, only one published study has demonstrated that the swab method is as effective as the traditional scrape method.”

A total of 25 pediatric patients (median age, 3.9 years, 52% boys) suspected of tinea capitis diagnosis were recruited from the Montreal Children’s Hospital and Children’s Clinic from July 2017 to July 2019. Participants underwent both scrape and swab methods for collection. In the scrape method, one side of a glass slide scraped the scalp while the other collected scale and broken hairs to be transported to the lab. For the swab method, a cotton tip was moistened and rubbed over the affected area and sent to the laboratory.

“For many years, the scrape culture method has been regarded as the gold standard for diagnosing tinea capitis. However, this method is uncomfortable for many pediatric patients, making it impractical,” Fatemeh Jafarian, MD, assistant professor at the division of pediatric dermatology at the McGill University Health Center in Montreal, told Healio. “The cotton swab technique is less invasive, requires minimal training, and is readily available in many institutions, making the technique more practical overall.”

This may increase patient compliance for evaluation and increase the willingness of families to undergo culture evaluation for therapy.
“The take-home message of our study is that using a cotton swab (such as the one used for obtaining a bacterial culture) is just as efficacious as the scrape technique for obtaining samples to diagnose tinea capitis,” Jafarian said.

Due to the numerous benefits to the swab technique, the researchers recommend and support adopting this technique in pediatric medicine to obtain samples to diagnose tinea capitis. – by Erin T. Welsh

Disclosures: The authors report no relevant financial disclosures.