**10. Special investigations**

**Biopsy (Histopathological and Direct Immune-Fluorescence Investigations (DIF))**: The clinical features alone may be sufficiently diagnostic, particularly when presenting with the "classic" reticular form. The evidence regarding the need and value of biopsy for histological confirmation of the diagnosis is not definitive. Studies have shown variability in both interobserver and intra-observer reliability in the clinicopathological assessment of OLP. [39] As OLP is a chronic disorder that often requires long-term treatment and monitoring, biopsy would be prudent clinical practice, particularly when the disease does not present with its typical manifestations, or when there is concern and therefore need, to exclude dysplasia or malignancy. [1] Furthermore, in severe disease warranting treatment with high-dose systemic corticosteroid therapy or potent "'steroid-sparing" immune-suppressant agents, then a confirmatory biopsy would be appropriate. The histopathological features are shown in Table 1. The findings on direct immune-fluorescence (DIF) are of a fibrin deposition in a linear pattern in the basement membrane zone. Colloid bodies may be positive for fibrin, IgM, and C3. The DIF findings, however, are not diagnostic of OLP, but DIF is certainly useful in differentiating OLP from other oral dermatoses, such as pemphigoid, or immune disorders, such as lupus (both discoid and systemic lupus) given their similar clinical presentation in the oral cavity. [34] Essential Features (for histopathological diagnosis):


∙ Normal epithelial maturation pattern (absence of epithelial dysplasia)

Non-Essential Histopathological Features that may also be seen:

"Candle-dripping" or "saw-tooth"-like rete ridge conformation

Parakeratosis

Lichenoid responses or reactions ("lichenoid stomatitis") of the oral cavity may also be noted with other autoimmune or inflammatory diseases including connective tissue diseases and other immuno-bullous disorders. The cause(s) of the various oral lichenoid lesions, ranging from idiopathic oral lichen planus (OLP) to the "contact" lesion, is not understood, but all the lesions are characterized histologically by a typical "lichenoid tissue reaction" culminating in a common pathologic process, that of T-lymphocyte directed, immune mediated, damage to

The diagnosis of OLP is usually made on clinical features alone. However, careful attention to the clinical history is essential, to ensure assessment, and if warranted, the appropriate management, of the extra-oral manifestations of lichen planus (Figures 8a and 8b). [1, 33-35]

**Biopsy (Histopathological and Direct Immune-Fluorescence Investigations (DIF))**: The clinical features alone may be sufficiently diagnostic, particularly when presenting with the "classic" reticular form. The evidence regarding the need and value of biopsy for histological confirmation of the diagnosis is not definitive. Studies have shown variability in both interobserver and intra-observer reliability in the clinicopathological assessment of OLP. [39] As OLP is a chronic disorder that often requires long-term treatment and monitoring, biopsy would be prudent clinical practice, particularly when the disease does not present with its typical manifestations, or when there is concern and therefore need, to exclude dysplasia or malignancy. [1] Furthermore, in severe disease warranting treatment with high-dose systemic corticosteroid therapy or potent "'steroid-sparing" immune-suppressant agents, then a confirmatory biopsy would be appropriate. The histopathological features are shown in Table 1. The findings on direct immune-fluorescence (DIF) are of a fibrin deposition in a linear pattern in the basement membrane zone. Colloid bodies may be positive for fibrin, IgM, and C3. The DIF findings, however, are not diagnostic of OLP, but DIF is certainly useful in differentiating OLP from other oral dermatoses, such as pemphigoid, or immune disorders, such as lupus (both discoid and systemic lupus) given their similar clinical presentation in the oral cavity. [34]

(a) (b)

the oral epithelial basal cells. [1,2]

160 Skin Biopsy - Diagnosis and Treatment

**Figure 8.** a) LP of the skin; b) LP of the skin (close up)

**10. Special investigations**

Civatte bodies

Separation of epithelium from lamina propria due to basal cell destruction

**Exclusionary Histopathological Features (the presence of which would preclude a definitive histopathological diagnosis of OLP).**

∙Epithelial Dysplasia/Atypia

→Atypical cytomorphology

→Nuclear enlargement or hyperchromasia

→Prevalent dyskeratosis

→Increased number of mitotic figures; aberrant mitosis

→Disordered stratification

∙Heterogeneous inflammatory infiltrate

Heterogeneous inflammatory infiltrate with plasma cells and eosinophils

Deep extension below superficial stroma

or perivascular infiltration

∙ Blunt rete ridges

**Table 1.** Histopathological features of OLP (adapted from Eisenberg, E. Clinicopathologic patterns of oral lichenoid lesions. Oral Maxillofac Surg Clin North Am, 1994, 6, 445.) [3] (Figures 9a, 9b and 9c)

**Figure 9.** a) Histopathology (low power) band-like inflammatory infiltrate; b) Histopathology – vacuolar degeneration of the basal keratinocytes; c) Histopathology – civatte body

**Laboratory Investigations:** Generally are not required, except in patients with severe OLP warranting high-dose systemic corticosteroids, with the need to exclude underlying latent infectious diseases that can be reactivated by the corticosteroids (HIV, Hepatitis B and C, and tuberculosis). Again generally not required, except if considering treatment with a suitable 'steroid-sparing systemic agent (e.g.: hydroxychloroquine (Plaquenil), azathioprine or methotrexate) then routine full blood count, and assessment of liver and renal function may be warranted, for baseline assessment and monitoring in patients needing long-term manage‐ ment. [33]

stem transplant recipients who have developed acute, or more commonly, chronic graftversus-host disease (cGVHD). There is evidence that there is a greater risk of malignant

Oral Lichen Planus

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http://dx.doi.org/10.5772/56482

The oral presentation of discoid lupus erythematosus (DLE) can also present with reticular or plaque-like lesions, but it is an uncommon condition that tends to present very much unilat‐ erally, so meriting biopsy for histopathological and direct immune-fluorescence investiga‐

An essential first step is patient education as to the chronic nature of OLP and that therapy is not curative, but directed at relieving their symptoms. For treatment to be effective, patients need educated regarding the need to be patient and persistent with the recommended therapy. Instilling in patients the need for ongoing monitoring, not only for patients' response to

The elimination of precipitating or provoking factors is an important initial step in the management of symptomatic OLP. The undertaking of active measures to resolve or minimize mechanical trauma from dental procedures, sharp cusps, rough dental restorations, and illfitting prostheses, or chemical trauma from acidic, spicy, or strongly flavoured foods and beverages should be encouraged. Of themselves, such supportive measures can lead to

The accumulation of bacterial plaque, often as a result of the discomfort associated with oral hygiene procedures in patients with gingival involvement, may also exacerbate the condition. The use of supplemental oral hygiene measures, including the use of alcohol-free chlorhexidine

Given the immune-mediated aetiology of OLP (and similar conditions such as mucous membrane pemphigoid (MMP)), the aim of therapy, is to minimise or "restrain" the body's immune-mediated inflammatory response, but without risking the activation of opportunistic infections. Treatment should be kept as simple as possible and should not inordinately burden the patient with expensive, complex, unwieldy or protracted treatments that result in noncompliance; therefore, topical corticosteroids remain the mainstay of treatment. [1, 33] Unfortunately, there are only limited evidence-based studies regarding the therapeutic

**Topical Treatment:Home Remedies and Over-the-Counter (OTC) Preparations:** patient prepared "salty" (saline) mouthwashes are of very limited clinical utility, somewhat palliative, and do not address the aetiological factors seen in OLP, but may facilitate oral hygiene. Patients also often self-prescribe and use any of the variety of OTC anti-microbial mouthwashes, in the

transformation with OLL-GVHD than seen with OLP. [40]

treatment, but for malignant transformation is also important.

symptomatic improvement, or, more rarely, resolution of the disease.

interventions in OLP, and so treatment remains largely empirical. [1]

gluconate mouth rinses, may be helpful in such cases. [41]

**11.1. Treatment**

**11.2. Supportive measures**

**11.3. Pharmacotherapy**

tions, the latter being most useful in distinguishing OLP from DLE. [34]

**Patch Testing and the Removal of Lichenoid-Inducing Dental Restorative Materials:** Idiopathic OLP needs to be distinguished from oral lichenoid contact lesions (OLCL), most commonly seen in direct topographic relationship with amalgam. Cutaneous patch testing, undertaken by a clinician skilled and experienced in "reading" the cutaneous response to a variety of test agents can be useful to confirm the diagnosis of a OLCL, [36, 37] especially in severe, symptomatic cases, in which wide-spread replacement of the amalgam fillings is being considered, given the expense in time and money to the patient concerned. The benefit of such patch testing is to ensure that the alternate dental restorative materials also, in turn, do not incite a lichenoid contact reaction (e.g.: as has been seen with gold and even composite materials). In select cases, and if practical, consideration should be given to the replacement of those isolated restorations, seemingly to be in direct topographic relationship with a lichenoid oral mucosal lesion, particularly if symptomatic, with an alternate material, but the patient needs to be counselled that this may not necessarily prove beneficial. As an interim step, temporary coverage of the suspecting inciting material may be considered to determine if resolution of the OLCL occurs before undertaking definitive removal and replacement of the suspected inciting material.

**Additional Measures:** Referral for examination by a dermatologist or gynaecologist should be considered, depending on the presenting signs and symptoms reported by the patient.
