Lichen Planopilaris: Histopathological Study of Vertical Sections of Scalp Biopsies in 44 Patients

LPP is one of the main causes of primary cicatricial alopecias. This study was performed for review of histo-pathological characteristics of LPP, and for the first time the density of hair follicles in vertical scalp biopsies was compared with healthy scalp biopsies. Vertically sectioned scalp 5mm punch biopsies of 44 cases of LPP were examined(H&E and Alcian blue) according to NAHRS criteria (1). Also we reviewed 22 age and sex matched scalp biopsies of autopsies for obtaining criteria for normal follicle number. We found normal values of hair follicles (15.24 ± 3.06), sebaceous glands (9.62 ± 2.29) and arrec-tor pili muscles number (9.05 ± 2.55) in a 5 mm punch biopsy. Based on normal ranges, intensity of reduction in terminal hair was as follows: mild (9-12), moderate (5-8) and marked (1-4 follicles). Characteristic findings of LPP were: markedly reduced hair density (63.6 %), absence of vellus hair (59.1 %), and follicular lichenoid changes (61.40 %). We found muci-nous fibroplasias (50.0 %) and presence of interfollicu-lar mucin (2.3 %). The only significant epidermal change was spongiosis (40.9 %). The most prominent pattern of follicular involvement was lichenoid (58.69%).Other changes included mild to moderate lymphocytic, primarily perifollicular (77.3 %) and perivascular (97.7 %) inflammation, Periinfundibular hypergranolosis (77.3 %), foreign body granuloma (13.6 %),demodex(25.0 %) , max-Josef cleft(38.6 %),epidermal(65.90 %) and follicular civatte bodies(45.45%). Vertical sections are useful in LPP in which the findings are focally confined to dermo-epi-dermal junction (DEJ) and superficial dermis (2). Common findings in LPP are as follows: lichenoid lym-phocyte infiltration in follicular DEJ (3-5), wedge shaped hypergranolosis (3, 5), Colloid bodies (5), loss of seba-ceous glands and destruction of hair follicle root sheaths (3, 6, 7) and follicular plugging (5). In late lesions, lamel-lar perifollicular fibrosis is seen around isthmus, and finally the follicles are completely substituted with fibrous tracts (3, 5). Lichenoid infiltrate disappears (5). Clefts may be seen between follicular epithelium and the dermis around it (5). In our study, decrease or lack of terminal hair was seen in 93.1% and vellus hair in 59.1%, arrector pili decrease in 36%, its lack in 9.1%, reduction in sebaceous glands in 36% and its lack in 52%. In Tandon study, these findings were in 100%, 96%, 59%, 19%, 30% and 70% respectively (4). In LPP, lichenoid changes are seen more than vacu-olar degeneration (8). In our study, follicular epithelium changes were lichenoid in 59.13%, spongiotic in 18.18% and …