ORAL LICHEN PLANUS

Introduction
Lichen planus (LP) is a relatively common disorder of
the stratified squamous epithelia (Duske and Frick,
1982; Scully and El-Kom, 1985; Conklin and Blasberg,
1987; Jungell, 1991). Most dental practitioners must see
patients with LP, but not all recognize this. The oral
(OLP) eruptions usually have a distinct clinical morphology and characteristic distribution, but OLP may also
present a confusing array of patterns and forms, and
other disorders may clinically simulate OLP. Lesions may
affect mucosae and/or skin.
The etiopathogenesis appears to be complex, with
interactions between and among genetic, environmental,
and lifestyle factors, but much has now been clarified
about the mechanisms involved, and interesting new
associations, such as with liver disease, have emerged.
The management is still not totally satisfactory, and
there is as yet no definitive treatment, but there have
been advances in the control of the condition.
This paper is the consensus outcome of a European
workshop held in 1995.


Epidemiology


LP is a fairly common mucocutaneous disease. OLP affects
from 0.1 to about 4% of individuals, depending on the
population sampled (Bruszt, 1962; Bouquot and Gorlin,


Oral Lesions



The clinical lesions of OLP normally include chronic
bilateral white reticular affections, typically in the posterior buccal mucosa (about 90% of cases), on the tongue
(about 30%), or on the alveolar ridge/gingiva (about
13%), but rarely on the palate or lip vermilion (Ax6ll and
Rundquist, 1987). Very occasionally, LP is seen on the
lips alone (Itin et al., 1995; Allan and Buxton, 1996). The
lesions usually consist of white lace-like slightly elevated
patterns (Fig. 1) and/or papules (Fig. 2) (Andreasen,
1968; Silverman et cil, 1991; Holmstrup et al, 1988). Other
types of clinical manifestations-such as plaque-type
(Fig. 3) or atrophic lesions, ulcerations (Fig. 4), or bullae-may be present simultaneously. At least some of
Figure 4. Erosive oral lichen plonus.
the lesions diagnosed as bullous LP are actually superficial mucoceles (Eveson, 1988).
While often asymptomatic, OLP may be associated
with chronic atrophic ulcerative erosive lesions which
commonly give rise to pain (Thorn et al, 1988). The prevalence of atrophic lesions of OLP in the adult Swedish
population is reported to be 0.56% and that of erosive
lesions 0.16%: among 410 diagnosed cases of OLP,
(32.7%) had atrophic lesions and 32 (7.8%) exhibited erosive lesions (Axell, 1976). In referred cohorts of OLP
patients, those with atrophic and ulcerative/erosive
lesions often constitute a higher proportion of the
patients; in the larger reported cohorts (Table 1), OLP
patients with atrophic lesions accounted for 5 to 44%,
whereas those with ulcerative/erosive lesions accounted
for 9 to 46%.
It is noteworthy that, in some cases of OLP, the clinical manifestations change completely over the years
(Thorn et al., 1988), one such development being the formation of plaque-type lesions which may even be present without other clinical lesions suggestive of OLP and
can present clinically as leukoplakia. One study has
reported on the course of the various clinical forms of
OLP (Thorn et al., 1988): Among 611 patients followed
from one to 26 years (mean, 7.5 years) (Table 2), 44% had
atrophic lesions at the initial visit, but in 23% of the
patients, these lesions had disappeared by the time of
the latest consultation, and another 12% had developed
atrophic lesions. Similar dynamics are characteristic of
the ulcerative lesions of OLP.
One analysis of the possible relationships between
and among age, sex, systemic disease, medication,
tobacco usage, and the presence of the various clinical
forms of OLP demonstrated that atrophic lesions were
most often found in individuals over 60, but no other correlations were found to explain the initial presence of
atrophic or ulcerative lesions (Thorn et al., 1988). An
interesting finding was that more plaque-type lesions
developed in patients who initially had atrophic and/or
ulcerative lesions than in those without (Thorn et al.,
1988). However, another study showed atrophic or erosive lesions to be more typically seen in the tongue and
sites other than the buccal mucosa than are reticular
lesions of LP, and the erosive forms were more likely than
the non-erosive to be associated with systemic disorders
such as chronic liver disease or diabetes mellitus (Bagan
et al., 1992). There is also evidence that it is these forms
of OLP that are more likely to develop carcinoma
(Barnard et al., 1993).
As mentioned above, atrophic and ulcerative/erosive
lesions of OLP are often associated with pain. As seen
from Table 1, pain or discomfort was recorded in 43 to
91% of the patients included in larger cohorts of OLP
patients. Obviously, the referred groups of patients are
selected, an important factor in the selection being the
presence of symptoms.