Diffuse variants of scalp lichen planopilaris: Clinical, trichoscopic, and histopathologic features of 40 patients.

Background: Fibrosing alopecia in a pattern distribution and cicatricial pattern hair loss are poorly recognized diffuse variants of lichen planopilaris (LPP).
Objectives: The medical features of 40 patients affected by a diffuse hair thinning associated with a long-lasting history of pruritus and erythema of the scalp and a histopathologic diagnosis of LPP were reviewed.
Methods: Clinical data, results of trichoscopy and histopathology, response to treatment, and follow-up were analyzed.
Results: There were 18 patients diagnosed with fibrosing alopecia in pattern distribution and 2 patients with cicatricial pattern hair loss. A new variant of diffuse LPP, named "lichen planopilaris diffuse pattern," was described in 20 individuals.
Limitations: Low number of cases due to rarity of the diseases.
Conclusion: In patients complaining of a long-lasting history of scalp erythema, itching/dysesthesia, and diffuse hair thinning, it is advisable to consider diffuse variants of LPP.
(Copyright © 2019 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.)