Follicular red dots: a novel dermoscopic pattern observed in scalp discoid lupus erythematosus.

BACKGROUND

Scalp dermoscopy plays an important role in the diagnosis of hair and scalp disorders, and specific dermoscopic patterns have recently been associated with several disorders causing noncicatricial alopecia, such as androgenetic alopecia, alopecia areata, trichotillomania, and tinea capitis.

OBSERVATIONS

We describe the morphologic and pathologic features of a new dermoscopic pattern, referred to as "follicular red dots," that was found in scalp lesions of 5 patients with active discoid lupus erythematosus (DLE). Follicular red dots appear as erythematous polycyclic, concentric structures, with a diameter ranging from 0.16 to 0.47 mm, regularly distributed in and around the follicular ostia. In the pathologic findings, red dots correspond to widened infundibula plugged by keratin and surrounded by dilated vessels and extravasated erythrocytes. Retrospective blinded evaluation of the dermoscopic images of 155 patients with cicatricial alopecia suggests that follicular red dots are a specific feature of DLE because the pattern was not identified in the images of cicatricial alopecia resulting from other diseases.

CONCLUSIONS

The follicular red dot pattern is a specific feature of scalp lesions of active lupus erythematosus of the scalp. Recognition of this distinctive dermoscopic pattern may help the clinician to differentiate DLE from other diseases causing cicatricial alopecia.