- A form of adult-onset scarring alopecia more common in women
- Presents with spinous hyperkeratotic follicular papules that progress to smooth patches of alopecia
- May coexist with lichen planus.
- Dense perifollicular lymphocytic lichenoid infiltrate
- Disruption of the follicular epithelial-dermal junction with glassy basal keratinocytes
- Exocytosis of lymphocytes into the follicular epithelium
- Dyskeratotic cells within the follicular epithelium
- Artifactual clefting between the follicular epidermis and dermis (Max Joseph spaces) may occur.
- Late lesions show complete follicular dropout with scattered naked hair shafts with surrounding granulomatous inflammation, indistinguishable from end-stage scarring alopecia of other etiologies.
- As in lichen planus, immunofluorescence shows IgM on cytoid bodies at the dermal-epidermal junction (nonspecific).
- The changes are quite similar to those seen in discoid lupus erythematosus, but dyskeratosis is more prominent in LPP and perivascular and perieccrine inflammation are more prominent in DLE, as is dermal mucin deposition.