Perifollicular Scale/Peripilar Casts
Frontal fibrosing alopecia (FFA) is a type of scarring alopecia. In some patients, eyebrow loss is one of the first signs of the disease whereas in others the frontal hairline is affected first. Many patients are asymptomatic although a bit of itching is not all that uncommon.
FFA can affect the frontal scalp as well as the sideburns and even around the back of the scalp (ie behind the ears). In fact, any body hair can be affected. The appearance of the scalp in various regions has been shown to appear differently by dermoscopy.
In 2018, Cevantes and colleagues compared the differences between the dermatoscopic appearance of the sideburns and the frontal scalp regions. The sideburn area in FFA was found to have less redness around hairs (perifollicular erythema) and less scaling (perifollicular scaling or peripilar casts) compared to the frontal scalp.
This information is helpful for physicians as we often rely on the presence or absence of perifollicular erythrma and scale as helping to decide if the FFA is active or not. This study reminds us that monitoring redness and scale makes sense when examining and monitoring the frontal scalp in patients with FFA but is of limited value when monitoring FFA of the sideburn area.
The dermoscopy photo shows the typical appearance of FFA of the frontal hairline. Scaling around hairs is known by many names including "perifollicular scale" and "peripilar casts."
Cervantes J, et al. Distinct Trichoscopic Features of the Sideburns in Frontal Fibrosing Alopecia Compared to the Frontotemporal Scalp.
Skin Appendage Disord. 2018.
Dr. Jeff Donovan is a Canadian and US board certified dermatologist specializing exclusively in hair loss. To schedule a consultation, please call the Whistler office at 604.283.1887