Prevalence of oral lichen planus in Gizan, Saudi Arabia

 
Gamil Salem, BDS, PhD
Dental Department, King Fahad Hospital, P.O. Box 204, Gizan, Saudi Arabia

This paper reports on the prevalence of oral lichen planus among 4277 dental patients aged 18-73 years, seen in the Dental Department, King Fahad Central Hospital, Gizan, Saudi Arabia, between 1982 and 1987. Oral mucosal lesions, diagnosed as lichen planus, were clinically and histologically identified in 72 subjects (40 males and 32 females). The average age of the affected group was 49 years. No correlation was evident between lichen planus and tobacco habits in this study, nor was there any association with diabetes or hypertension. The average period of follow-up was 3.2 years, during which time 4 patients developed malignant transformation of their oral lesions. The prevalence of lichen planus in this study was 1.7%, which is higher than the prevalence figures reported earlier for this disease in Saudi Arabia.

Varying prevalence rates of oral lichen planus have been reported in different parts of the world.1-4 Information regarding the epidemiology of this dis­ ease in Saudi Arabia is incomplete.5 The oral lesions of lichen planus show great variation in clinical appearance and up to eight different forms have been described.6 The question of lichen planus as a possible precancerous lesion has been raised frequently with controversy in opinion.4,7-10 This paper reports on the prevalence of oral lichen planus, its clinical characteristics and associated findings in a defined group of Saudi Arabian popu­ lation observed for five years.

The study material comprised 4277 patients (63% males and 37% females) aged 18 to 72 years, seen in the Dental Department, King Fahad Central Hospital, Gizan, between 1982 and 1987.The criteria for both the clinical and histologic diagnoses of lichen planus were those described by Shafer et al.1T The following histologic features were required to establish the diagnosis:

1)  Liquefactive degeneration of basal layer cells.

2)  Band-like infiltrate of lymphocytes within the lamina propria.

3)  Hyperkeratosis or parakeratosis.

The distribution of oral lesions was recorded for each patient with the aid of a diagram presented by Roed-Petersen and Renstrup12 for the topographi­ cal classification of the oral mucosa. Informationwas obtained concerning the onset of the oral lesion, associated skin lesions, consumption of drugs and tobaccohabits.Biopsywasobtainedfromtheorallesiontoconfirmdiagnosis. All patients were referred to the medical clinic for investigation with regard to any associated sys­ temic diseases if any, notably, diabetes and hyper­ tension. Patients were seen regularly every two months and/or by the time of exacerbation of the painful symptoms. Another biopsy was taken when premalignant or malignant changes were sus­ pected. Patients with severe painful symptoms were given topical steroid (Betamethasone 1%) and a surface anesthetic (Xylocaine 2% jelly). No systemic therapy was given.

Lichen planus was clinically and histologically identified in 72 patients of which 68 presented with painful symptoms, while in 4 patients the lesions were asymptomatic. The age and sex distribution of the patients are shown in Table 1.

The findings are presented for the two sexes combined. Only four clinical forms of lichen planus were identified: 1) reticular form, 2) plaque or hypertrophic form, 3) atrophic form, and 4) erosive form.

The anatomical distribution of the four clinical forms identified are shown in Table 2. Characteris­ tics of the patients with oral lichen planus are shown in Table 3. Table 4 shows the incidence of systemic disease among patients with oral lichen planus. All patients showed both remissions and exacerbations of the painful symptoms. Eight patients did not show up after the first examination. The remaining patients were reviewed regularly. The average period of follow-up was 3.2 years, during which time 4 patients developed squamous cell carcinoma at the site of the oral lesion [Fig. 1].

The population of Gizan is 627,466, constituting one-sixth of the total population of Saudi Arabia.13 The prevalence of oral lichen planus in this study was 1.7%, which is higher than the prevalence figures reported earlier for the population of Saudi Arabia.5

In this study, 94% of the affected patients were over 30 years old. The average age was 49, and the affected women of age 60 or over outnumbered the men in agreement with earlier reports.14-15

No examples of the bullous, vesicular15, 16 or the papular forms of lichen planus were identified in this study. The erosive form dominated in this study (38.8%). The atrophic form came next (30.6%), while the plaque (hypertrophic) form was the one least encountered (5.5%). The reticular form accounted for 25% of all the cases of lichen planus in this study.

The cheek mucosa was a common site for all forms of lichen planus and was involved in 86% of the cases in this study. The tongue was involved in 42.7% of the cases and was a common site for lesions of both the atrophic and the erosive forms. The gingiva was involved in 16.5% of the cases, mostly by the reticular form (Table 3). These find­ ings are comparable with the values reported ear­ lier.1-6,14-17 Skin lesions were found in 4.2% of patients with oral lichen planus. In some of the pre­vious studies, skin lesions were reported in 44% of the cases in one study,16 and 25% and 35% in two other studies, respectively.10, 14 Some studies had, however, demonstrated that oral lichen planus may occur without any skin lesions.15

No positive family history of similar lesions was obtained in this study. Tobacco smoking did not appear to be related to the occurrence of lichen planus in this study.4,10,16

Some investigators had associated lichen planus with diabetes and hypertension.18-22 In our find­ ings, the number of patients in whom diabetes was diagnosed (Table 4) did not exceed what had been expected in a general population of Saudi Arabia.23, 24, 25 The other systemic disorders (e.g.
renal failure and hepatitis B) observed in this study could not be correlated with the presence of oral lichen planus.

It should be emphasized, however, that this study does not represent the actual prevalence of

oral lichen planus in Saudi Arabia but rather in Gizan. Further studies are needed to cover the epidemiology of this disease in Saudi Arabia.