Sea of Singles (SOS): A Potential Sign of Scarring Alopecia

Lichen planopilaris (LPP) is a type of scarring hair loss condition. Patients frequently present with scalp itching, and sometimes scalp burning and tenderness. Increased hair shedding is common in the early stages. Hair loss is generally permanent and treatment helps stop the disease or at least slow down progression.

Clinically, dermoscopy (trichoscopy) of LPP often shows perifollicular erythema and perifollicular scale (follicular keratosis).

These findings are not present in all forms of LPP. A less common presentation of LPP is shown in the photo. Patients have hair loss with scalp itching. However, by dermoscopy they have many single hair follicles growing in a base of redness. This is what I have termed the "sea of singles" (SOS) appearance to describe the numerous single hairs and absence of hair follicle units containing 2 and 3 hairs. This form of LPP is similar to Abbasi's subtype described in 2016 and fibrosing aloepcia in a pattern distribution described by Zinkernagel in 2000. The "SOS" trichoscopic appearance is important to remember and provides a clue that the patient may have a scarring alopecia.

 

Reference

Zinkernagel MS et al. Arch Dermatol 2000

Abassi A et al. Dermatol Surg. 2016.