Case #7
A 22-year-old male visited the dental office for evaluation of a white area in the buccal vestibule.
Joen Iannucci Haring, DDS, MS
History
When questioned about the white area, the patient stated that he first noticed it several months earlier. He remarked that the area was not painful and denied any history of trauma. The patient appeared to be in a general good state of health. No medications were being taken at the time of the dental appointment.
Examinations
Examination of the head and neck region revealed no palpable lymph nodes. All vital signs were found to be within normal limits. Oral examination revealed one lace-like white patch extending from the attached gingiva and alveolar mucosa on to the buccal mucosa (see photo). The lesion appeared to be slightly raised and could not be removed by wiping or scraping. No other lesions were noted in the oral cavity.
Differential diagnosis
Based on the clinical information presented, which of the following is the most likely diagnosis?
* leukoplakia
* reticular lichen planus
* hyperplastic candidiasis
* discoid lupus erythematosus
* white sponge nevus
Diagnosis
reticular lichen planus
Discussion
Erasmus Wilson, a British physician, first described lichen planus in 1869. The term lichen refers to the primitive plants found on rocks and trees, and the term planus is Latin for flat. Wilson believed that the skin lesions of lichen planus resembled lichens growing on rocks.
Lichen planus should be of interest to the dental professional because it is one of the most common dermatologic disorders with oral manifestations. Lichen planus (LP) is a chronic disease that not only affects the oral mucous membranes but the skin, nails and hair follicles as well.
Lichen planus is a disease of adults; most cases are seen in individuals older than 40. Women are more frequently affected than men. Cutaneous LP is estimated to affect approximately 2 percent of the adult population, while oral LP affects 2 percent or less.
The cause of lichen planus is unknown. Suggested theories include autoimmune, allergic, genetic and psychosomatic. Currently, the initiating event in the development of lichen planus is unknown. However, the available evidence favors the autoimmune theory in the evolution of the lesions. Lichen planus is not an infectious disease, and there is no risk to the dental professional in treating patients with skin or oral lesions.
Cutaneous LP
The skin lesions of LP may develop concomitantly or independently of oral lesions. Approximately half the cases of cutaneous LP occur with oral lesions. In many instances, oral lesions may occur without skin lesions. It is not uncommon, however, to see oral lesions accompany or precede the appearance of skin lesions.
Clinical appearance. The clinical appearance of cutaneous LP is characteristic. The "five P`s" used to describe the skin lesions are papular, planar, purple, polygonal, and pruritic.
The skin lesions appear as small reddish-purple, polygonal papules. Close examination of the papules reveals fine, lacy-white lines, or striae. Referred to as Wickham`s striae, they are named for the L.F. Wickham who first described them in 1898.
The papules of cutaneous LP may appear separate and discrete or coalesce to form large plaques. Initially the skin lesions appear reddish-purple. With time, the color changes to a dark brown. Cutaneous LP may be found on any skin surface. The flexor surfaces of the wrists, forearms, and ankles and the inner surfaces of the knees and thighs are the most common sites of involvement. The primary symptom of cutaneous LP is severe pruritis (itching).
Diagnosis. The diagnosis of cutaneous LP is often made based on its characteristic clinical appearance. To confirm such a clinical diagnosis, a biopsy, histologic examination, and immunofluorescence studies are used.
Treatment. A person with cutaneous LP is typically treated by a dermatologist. The majority of cases of cutaneous LP are self-limiting. The pruritis is usually alleviated with potent topical corticosteroid preparations such as fluocinide and betamethasone. In severe, generalized cases, short tapering courses of moderately high doses of systemic corticosteroid medications are indicated.
Oral lichen planus
The course of oral LP is chronic; the lesions may exist for a period of months or years. The oral lesions tend to persist longer than their cutaneous counterparts. Oral LP differs in appearance from cutaneous LP.
Clinical types. Clinically, four types of lichen planus are found in the oral cavity. Each type has a different clinical appearance.
* Reticular lichen planus
* Erosive lichen planus
* Hypertrophic lichen planus
* Bullous lichen planus
Reticular lichen planus. The most common type of oral LP is termed reticular. The reticular form has a classic "lace-like" appearance. Numerous, interlacing white lines termed striae are seen in a reticular (net-like), annular (ring-like), or a linear pattern. The most common location is the posterior buccal mucosa; other areas of involvement may include the tongue, gingiva, and palate. The reticular lesions may involve large areas of the oral mucosa and do not rub off. These lesions may wax and wane and may last for months. Reticular LP is usually asymptomatic and does not require treatment.
Erosive lichen planus. Erosive lichen planus (ELP) is not as common as reticular LP. However, because the lesions of ELP are typically symptomatic, this form is more significant to patients. Clinically, ELP appears as shallow ulcerations or erosions. A white keratotic component is observed at the periphery of the erosions. Numerous white striae are seen radiating from the area of erosion.
ELP is most often found on the buccal mucosa. Other sites of involvement include the tongue, gingiva, palate, lip, and floor of the mouth. ELP is often multifocal, involving more than one intraoral site. As with most oral ulcerations and erosions, the symptoms associated with ELP are described as mild to moderate pain and burning. Patients with ELP often describe a burning sensation with the ingestion of acidic fruits, juices, sauces, and spicy foods.
ELP is a chronic disease and runs a protracted course. The lesions of ELP may resolve in one area of the mouth and then appear in a different location. The lesions of ELP may wax and wane and persist for a period of months or years.
Hypertrophic lichen planus. The hypertrophic form of oral LP is exceedingly rare. Clinically, this lesion resembles a leukoplakia. Hypertrophic LP appears as an elevated, well-defined homogeneous plaque that cannot be rubbed off. It is typically asymptomatic.
Bullous lichen planus. The bullous form of oral LP is also exceedingly rare. Clinically, this lesion is characterized by the formation of bulla (large fluid filled elevations). The bullae rupture and leave painful, large raw and eroded areas of oral mucosa. In order to distinguish the bullous form of LP from the erosive form, bullae must be present.
Differential diagnosis
The reticular form of lichen planus has a characteristic clinical appearance and can readily be distinguished from other white lesions found in the oral cavity. The erosive form and bullous form of lichen planus may be clinically confused with other oral conditions characterized by painful ulcerations. Pemphigus vulgaris, benign mucous membrane pemphigoid, lupus erythematosus and erythema multiforme are some of the conditions that may be considered in the differential diagnosis.
Diagnosis
A diagnosis of reticular LP is established on a clinical basis. The characteristic white striae are virtually pathognomonic. With the exception of the reticular LP, a biopsy and/or immunofluorescence studies are required to establish a definitive diagnosis. If ELP is suspected, a patient should be referred to an oral surgeon for a biopsy. The biopsy specimen must include both lesional and normal tissue. In cases of nondiagnostic biopsy specimens, direct immunofluorescence studies can be used.
Treatment
Reticular lichen planus. No treatment is required for reticular lichen planus.
Erosive lichen planus. Patients with erosive lichen planus may be treated and managed by either the general dentist or an oral pathologist. The former may be better suited to manage severe cases.
If the patient is symptomatic, many times a superimposed candidiasis is responsible for the symptoms associated with ELP. With symptomatic cases of ELP, it is prudent to perform exfoliative cytology in order to evaluate for candidiasis. If candidiasis is present, antifungal medications should be prescribed, since the candidiasis should be treated first.
If the symptomatic ELP patient shows no cytologic evidence of candidiasis or remains symptomatic after the treatment of candidiasis, the use of corticosteroid medications is warranted. Depending upon the extent and severity of the lesions, topical or systemic corticosteroid preparations may be utilized. Although systemic corticosteroid medications should be prescribed by a physician, topical corticosteroid preparations can be prescribed by the dentist.
Lichen planus and the dental patient
Lichen planus is not an infectious disease, and there is no operator risk involved in treating patients with skin or oral lesions. All patients with oral lesions should be questioned about the presence of skin lesions. If skin lesions are present, the patient should be referred to a dermatologist.
Patients with symptomatic oral ELP can be managed and treated by the general dentist. Severe cases, however, should be referred to the oral pathologist for management. All patients with symptomatic ELP should be advised to avoid acidic fruits and juices, as well as spicy foods.
Joen Iannucci Haring, DDS, MS, is an associate professor of clinical dentistry, Section of Primary Care, The Ohio State University College of Dentistry.
