Scaring Alopecia

Pseudopelade (PP) is a cicatricial alopecia whose exact pathogenesis is still unknown. But increasing evidence suggests that it is the end stage of various diseases which lead to scarring alopecia. We have evaluated the clinico-immunopathological features of scarring alopecia due to lichen planus (LP), pseudopelade (PP) and lupus erythematosus (LE) in 27 patients. Paired punch biopsies (3-4 mm) were obtained from the border of the extending lesion and the central scarred area to study different stages of the disease process. One half of each of the paired biopsies was used for histopathological and direct immunofluorescence studies respectively. Variable destruction of the hair follicles and their replacement with fibrosis and elastic fibres was observed in most of the patients with LP, PP or LE. Direct immunofluorescence studies were mostly negative or nonspecific. Our resuits suggest that pseudopelade is the end stage of various diseases which lead to cicatricial alopecia rather than a nosological or distinct entity by itself
Key words Lichen planopilaris - pseudopelade - scarring alopecia
Cicatricial alopecias are a diverse group of diseases characterized by a combination of follicular destruction and scarring leading to permanent hair loss. Scarring alopecias can be classified into primary and secondary on the basis of histopathological features1,2. In the early stages, the diseases leading to scarring alopecia have some distinguishing clinical and histological characteristics, but in the later stages the differentiation between the commoner cicatricial alopecias is difficult particularly with regard to pseudopelade and its relationship to lichen planus and/or lichen planopilaris and discoid lupus erythematosus3-8. As a result the nosology of pseudopelade is controversial and it is not known whether it is a distinct entity or a syndrome which is the end result of any one of a number of different pathological processes. Hence the present study was undertaken to evaluate the clinico-immunopathological features in 27 patients with cicatricial alopecia.
Material & Methods
Twenty seven patients of different ages and both sexes with cicatricial alopecia were recruited from the Dermatology Department of the Postgraduate Institute of Medical Education and Research, Chandigarh, during July 1994 to September 1995. Age, sex, duration and associated cutaneous and/or systemic diseases if any were recorded. The diagnosis was made on the basis of history, clinical features and the course of the disease and the patients characterized as having PP, LP or LE based on standard descriptions9.
Paired punch biopsies (3-4 mm) were obtained from the border of the extending lesion and the central scarred area to study the different stages of the disease process. The punch was inserted so as to orient along the long axis of the hair shafts. One half of each of the paired biopsies was used for histopathological (HPE) and direct immunofluorescence (DIF) studies respectively. For histopathological examination tissue samples were fixed in 10 per cent formalin saline, embedded in paraffin, cut into 4-5 (mu) thick sections and stained with haematoxylin and eosin (H & E) and van Gieson's (EVG) stain for elastic fibres. Paired comparisons of all the histopathological features were analysed using Fisher's exact test.
For DIF, fluorescein labelled monospecific antisera raised against IgG, IgA, IgM and complement, were used. Four frozen sections from each biopsy were incubated with fluorescein isothiocynate (FITC) labelled antihuman immunoglobulin and complement for 30 min at 37 deg C. The slides were screened in incidental light under Ziess 16 research microscope fitted with an HBO 50 ultraviolet lamp. The immunofluorescence pattern was studied and the positivity graded semiquantitatively as strongly positive (+++), moderately positive (++), weakly positive (+) and negative (0).
 

Clinical findings: The 27 patients with scarring alopecia included 11 men and 16 women (mean age 32.4 yr; range, 12 to 59 yr). The average duration of alopecia was 3.3 yr (range, 1 month to 30 yr). The vertex was the commonest site involved in 20 patients (74%), followed by temporo-occipital region in 3 (11%), frontal region in one (4%) and near total involvement of the scalp in 3 ( I %) patients.
Lichen planus: Of the 15 patients, 10 were females and 5 males. Five patients had associated cutaneous LP and in two there were classical lesions of LP on the oral mucous membrane. One patient had diabetes mellitus. Most patients were in the age group of 31-40 yr. Pseudopelade: Ten patients (6 males and 4 females), exhibited multiple irregular patches of alopecia on the vertex. Most of the patients in this group were aged 21-30 yr.
Lupus erythematous: Both patients with LE were females and were aged 26 yr.
In both LP and LE patients, the vertex was the commonest site involved as in patients with PP.
Histopathological and direct immunofluorescence findings: In the 30 biopsies from LP patients, the characteristic feature, the interface alteration  at the follicle basal cell layer was seen in 4 biopsies from the centre and 5 from the periphery of the lesion. Significant perifollicular inflammation was seen in only one section from the centre and 3 from the periphery. Hair follicles were absent in 7 sections from the centre and 4 from the periphery. Sebaceous glands were absent in all but one section. The most striking feature, linear and/or concentric fibrosis with elastic fibres  was noted in 12 samples from the centre and 10 from the periphery. DIF studies were mostly negative. Only 3 sections showed IgM deposits and IgG, and IgA were seen in 2 biopsies each.
Of the 20 biopsies from patients with PP, significant finding of epidermal thinning was observed in 8 sections from the centre and 6 from the periphery. There was significant destruction of the pilosebaceous structures which were replaced by linear and/or concentric fibrosis  with elastic fibrosis in 7 biopsies from the centre and 3 from the periphery. The results of DIF were generally negative in patients with PP. An occasional biopsy showed faint IgM deposits at the dermoepidermal junction.
The main histological features noted in LE patients were follicular plugging, vacuolar basal cell degeneration deep perieccrine inflammation and destruction of the follicles with fibrosis and elastic fibres.
Various histopathological and direct immunofluorescence findings are depicted in Tables I and II respectively.
The opinion in literature as to the nosological entity of pseudopelade is divided. While some workers10,11 have stated that PP is a distinct entity others have described it as a result of a variety of identifiable causes12. In the present series we have tried to evaluate the clinicoimmunopathological features in 27 patients. We observed a female preponderance with the sex ratio being 2:3 (M:F) as has been reported earlier13. Most of our patients gave a history of a slow and insidious progression of the disease. In the lichen planus group it varied from one month to 3 yr with an average of 1.3 yr. Nayar et al14 also observed a chronic course of the disease. In the PP group the longest duration was 30 yr and the shortest 9 months (average 6.7 yr), as has also been reported earlier"'5. The average duration in both the cases of LE was 2 yr.
The classic histopathological features of LP were rarely observed in the biopsies of our patients with lichen planus. Epidermal atrophy and flattening of the rete ridges seen in 73 per cent of the biopsies from both the centre and periphery is in agreement with previous observations3,4. Interface alteration at the DEJ was observed in 27 and 33 per cent of the biopsies from the centre and periphery respectively which is consistent with the observation of Nayar et al14. However, others34 did not observe these changes very often. Perifollicular inflammation was seen in only 6 per cent of the sections from the centre and 20 per cent from the periphery whereas Panja and Jaiswal3,4 observed similar changes in 80 per cent of their patients. A variable degree of either loss or atrophy of hair follicles seen in most of the sections from our patients with LP has been reported earlier3,4,16. The findings of linear and/or concentric fibrosis with variable amounts of elastic fibres in relation to hair follicles in most of the biopsies from both the centre and periphery are in concordance with those of some workers 11,12,15,17 but are in variance with those of others;3,4,18-20. DIF studies in our cases with LP were mostly negative, however, significant DIF positivity has been reported earlier21,22.
Significant focal and/or diffuse epidermal thinning with flattening of the rete ridges observed both from the centre and periphery in most of our patients with PP has been reported earlier3,4. Consistent with the earlier studies3,4,11,20 none of our PP patients had interface alteration. However, Nayar et al14 observed basal cell vacuolation in one of their three cases. In concordance with earlier series3,4,11.20 mild to moderate cellular infiltrates were observed in only a minority of sections. The most striking feature of disappearance of hair follicles and their replacement with fibrosis and elastic fibres seen by us has also been observed earlier3,4,19,20. However, the absence of elastic fibres in the cicatrized follicles has been described 10,23. Consistent with previous reports3,4, loss of subepidermal elastic fibres was also seen in most of our cases. In concordance with others11,14 the results of DIF in our cases with PP were generally negative with an occasional biopsy showing faint positivity.
The significant histological changes of vacuolar degeneration with subepidermal cleft, perifollicular and perieccrine inflammation noted in both the cases with LE have already been described3,4. Biopsies from both patients showed fibrosis with elastic fibres in relation to the destroyed hair follicles as seen in LP and PP patients.
In all our cases of PP, LP and LE with scarring alopecia the loss of hair follicles and their replacement with fibrosis was more in the biopsies taken from the centre (the difference was statistically significant).