**11. Lichen Planopilaris (LPP)**

LPP is a rare type of lichen planus which characteristically affects the scalp (Figure 8) with perifollicular erythema, keratotic follicular spines and with patchy or diffuse hair loss which may result in scarring alopecia as its end stage. Scalp lesions can be associated with charac‐ teristic flat topped violaceous papules of lichen planus (LP) on the limbs in 50 % of cases [10]. LPP of the scalp is a scarring disease and it is difficult to treat comparing to the glabrous LP and this has major psychological consequences for the affected patients. The therapeutic management often is quite challenging, as relapses are common after local or systemic treatments. The recommended treatments are ultrapotent topical or intralesional injections of corticosteroid. Some cases may need systemic treatment including oral corticotherapy and cyclosporine.

#### **Figure 8.** LPP of the scalp.

collagen component antigens in the BMZ with gross thickening and protrusion into the dermis

**Figure 7.** Anti-type IV collagen staining in DLE with an exaggerated expression as demonstrated by thickness of the

LPP is a rare type of lichen planus which characteristically affects the scalp (Figure 8) with perifollicular erythema, keratotic follicular spines and with patchy or diffuse hair loss which may result in scarring alopecia as its end stage. Scalp lesions can be associated with charac‐ teristic flat topped violaceous papules of lichen planus (LP) on the limbs in 50 % of cases [10]. LPP of the scalp is a scarring disease and it is difficult to treat comparing to the glabrous LP and this has major psychological consequences for the affected patients. The therapeutic management often is quite challenging, as relapses are common after local or systemic treatments. The recommended treatments are ultrapotent topical or intralesional injections of corticosteroid. Some cases may need systemic treatment including oral corticotherapy and

in active DLE lesions (Fig 7).

20 Skin Biopsy - Diagnosis and Treatment

basement membrane and protrusions.

cyclosporine.

**11. Lichen Planopilaris (LPP)**

Histologically (Fig 9) has been reported to show two different patterns [11], each pattern characterized by the presence of specific histological features that reflects the specific stage of the progression of the disease. In the first pattern, hair follicles and the perifollicular dermis were mainly involved in the pathologic process, with no involvement of the interfollicular structures. In the second pattern, the pathologic changes extended to the interfollicular epidermis and the papillary dermis.

**Figure 9.** LPP pathology. The inflammation is mainly perifollicular with some involvement of the basal cell layers which also show basal cell degeneration.

Direct immunofluorescence highlights the presence of colloid bodies in the peri-infundibular area staining with IgM (less frequently with IgG, IgA and C3).

topical minoxidil, irritants (anthralin or topical coal tar), and topical immunotherapy. Oral corticosteroids decrease the hair loss, but only for the period during which they are taken.

Scalp Biopsy and Diagnosis of Common Hair Loss Problems

http://dx.doi.org/10.5772/55025

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Diagnostic pathological findings (Fig 12) are more prominent in this type of alopecia which characterize by peribulbar lymphocytic inflammation which is usually considered to be an

infiltrate is rich in helper T cells, which are considered to be evidence of an autoimmune process. Despite this, it may be absent in many scalp biopsy specimens. In the acute stage; a moderate to dense inflammatory cell infiltrate (mainly lymphocytes and langerhans cells) [14] develops around anagen hair and this leads finally to anagen arrest and inhibition which

hair shaft. Using follicular counts [15] related to the stage of disease is a useful way to establish the histologic features of alopecia areata in scalp biopsy specimens taken from different types of alopecia areata; alopecia areata should be suspected when high percentages of telogen hairs

essential finding in establishing the diagnosis [13]. The lymphocytic

are present, even in the absence of a peribulbar infiltrate [15].

**Figure 11.** Alopecia areata in a child presented with diffuse hair loss.

weakens the lowest portion of the

By immunohistochemistry staining [12], there is a significant alteration in the basement membrane structure in lesions of LPP which could differentiate it from active lesions of scalp DLE lesions.
