Can Trichoscopy Suggest the Agent in Tinea Capitis?

Area of Science:

• Dermatology
• Mycology
• Medical Diagnostics

Background:

• Traditional diagnosis of tinea capitis (Tc) relies on mycological examination and culture, which have lengthy turnaround times (4-6 weeks).
• Trichoscopy, a non-invasive examination of hair and scalp, shows potential as an adjunct diagnostic tool for Tc.
• Identifying specific trichoscopic patterns associated with different causative agents could expedite diagnosis and treatment.

Purpose of the Study:

• To evaluate the association between specific trichoscopic patterns and the etiological agents of tinea capitis (Tc).
• To determine if trichoscopy can differentiate between common Tc fungal pathogens, *Microsporum canis* (*M. canis*) and *Trichophyton tonsurans* (*T. tonsurans*).
• To assess the utility of trichoscopy as a rapid diagnostic method for Tc, especially in resource-limited settings.

Main Methods:

• A retrospective, cross-sectional study of 110 patient records with suspected Tc was conducted.
• 31 patients underwent trichoscopy, followed by direct mycological examination (10% KOH) and fungal cultures.
• Statistical analysis (Fisher's exact test) was used to correlate trichoscopic findings with confirmed etiological agents (*M. canis*, *T. tonsurans*).

Main Results:

• Nonspecific trichoscopic findings like perifollicular desquamation and broken hairs were observed.
• Morse code (barcode-like) whitish sheaths were more frequently associated with *M. canis* infections.
• Comma hairs and black dots were more common in *T. tonsurans* infections.

Conclusions:

• Trichoscopy findings can suggest the pathophysiology of tinea infection based on parasitism type (ectothrix vs. endothrix).
• Specific trichoscopic patterns, such as Morse code hairs, comma hairs, and black dots, show potential for differentiating between *M. canis* and *T. tonsurans*.
• Trichoscopy is a valuable tool for diagnosing tinea capitis, particularly where laboratory facilities are limited.