Psychosocial burden of lichen planus pigmentosus is similar to vitiligo, but greater than melasma: A cross-sectional study from a tertiary-care center in north India

Study population

Patients with a clinical diagnosis of lichen planus pigmentosus, vitiligo and melasma were included in the study. To differentiate lichen planus pigmentosus from other similar entities (ashy dermatosis, erythema dyschromicum perstans and pigmented cosmetic dermatitis), its diagnosis was made by two experienced dermatologists based on the clinical features of slate-gray-to-brown macules on the face with or without involvement of other sites (trunk, flexures) in the absence of preceding erythema or inflammation. The pigmented macules lacked an erythematous halo. Possibility of a contact allergen causing the pigmentation was excluded by a lack of temporal correlation on detailed history and the pattern of pigmentation on clinical examination. 5,10 Patients ≥18 years of age were included in the study after giving informed consent. Patients with other skin diseases concurrently and those with psychiatric comorbidities were excluded.

Quality-of-life measures

Dermatology Life Quality Index (DLQI), vitiligo impact scale (VIS)-22 and a global question were used for measuring the quality of life in the study patients with lichen planus pigmentosus, vitiligo and melasma. The DLQI is a valid and reliable dermatology-specific quality-of-life instrument containing ten items related to different domains of life. Each item is scored on a scale of 0–3 (0-not at all, 1-a little, 2-a lot, 3-very much), and the total scores range from 0–30.¹¹ We anticipated that DLQI, being a general dermatology instrument, might not be sensitive enough to the unique quality-of-life issues in patients with pigmentary dermatoses. In the absence of an instrument specific for pigmentary dermatoses, we chose VIS-22, an instrument developed and validated in Indian patients with vitiligo. It has 22 items related to different domains of life: attitude (items 1, 4, 17, 19), anxiety (2, 11), social interactions (3, 12, 13), self-confidence (5, 18), depression (6, 9, 10, 14), treatment (7, 15, 16), family (8), marriage (20), occupation (21) and school or college (22). Each item is scored from 0–3 (0-not at all, 1-a little, 2-a lot, 3-very much), and the total scores range from 0–66 with higher scores indicating a higher effect on life. Its reliability and responsiveness have been demonstrated in vitiligo, and clinical meaning has been assigned to its scores.^12,13 A modified version of VIS-22 was used as a quality-of-life measure for lichen planus pigmentosus and melasma, after testing its validity in patients with these diseases. The modified version of VIS-22 differed from VIS-22 in only one question (item 20) where the phrase “white patches” was replaced with “patches”. In addition to DLQI and modified version of VIS-22/VIS-22, a global question (“How much does your skin disease affect your life?”) concerning the effect of the disease on the patients’ lives was also asked. The response was on a five-point Likert scale: 0, no effect; 1, mild effect; 2, moderate effect; 3, large effect and 4, very large effect.

Pretesting of modified VIS-22 in patients with lichen planus pigmentosus and melisma

Study participants with lichen planus pigmentosus (n = 35) and melasma (n = 20), recruited through purposive sampling, were asked to answer the modified version of VIS-22. Participants were then interviewed regarding the clarity, understandability and relevance of individual items of modified VIS-22, and also whether any aspect of their disease is not covered in the modified VIS-22.

Validity of modified VIS-22 in patients with lichen planus pigmentosus and melisma

DLQI, modified VIS-22 and global question were self-administered by a separate cohort of patients with lichen planus pigmentosus and melasma. Concurrent and convergent validities were assessed by correlating the scores of modified VIS-22 with that of the global question and DLQI, respectively. Known-group’s validity was calculated by comparing the scores of modified VIS-22 between patients grouped on the basis of gender, disease duration, disease progression, number of sites and body surface area affected, education, marital and employment status. These analyses were done separately for patients with lichen planus pigmentosus as well as melasma.

Statistical analysis

Quality of life was estimated by global question scores and the overall scores of modified VIS-22 / VIS-22 and DLQI. Scores for individual domains of modified VIS-22 / VIS-22 and DLQI were also calculated. Continuous variables are reported as mean (standard deviation, range), and categorical variables as frequency (%). Continuous variables were compared using student’s t-test or Wilcoxon ranksum test, and categorical variables by Chi-square test or Fisher’s exact test, as applicable. Correlation between two quality-of-life measures was tested using Pearson’s correlation coefficient (r). Clinicodemographic variables associated with impairment in quality of life were identified by univariate and stepwise multivariate logistic regression analysis (with a probability to enter = 0.051 and probability to remove = 0.1) using dichotomized DLQI scores (0–10, no-moderate effect vs. 11–30, large or very large effect) and global question scores (0–2, no-moderate effect vs. 3–4, large or very large effect) as dependent variables, as well as stepwise multiple linear regression analysis using continuous DLQI and modified VIS-22 scores. A P value < 0.05 was considered statistically significant. Statistical analysis was done using Stata version 14.0 (StataCorp, College Station, TX, U. S. A.).

Pretesting and validity of modified VIS-22 in lichen planus pigmentosus and melisma

The modified VIS-22 was first administered to 35 (10 men, 25 women; mean age 35.5 ± 11.7 years) patients with lichen planus pigmentosus and 20 (6 men, 14 women; mean age 36.6 ± 7.8 years) patients with melasma. Three (8.6%) patients with lichen planus pigmentosus reported at least one item as not relevant to their disease (items 4, 7, 9, 13, 14, 16 and 17, of which items 9 and 14 were reported by two patients each). Six (30%) patients with melasma reported at least one item as not relevant to their disease (items 1, 3, 4, 5, 6, 8, 9, 13, 14 and 20 of which item 4 was reported by four patients and items 6, 13, 14 and 20 by two patients each). None of the patients with lichen planus pigmentosus or melasma reported any additional question to be added to modified of VIS-22.

The modified VIS-22 scores showed moderately good correlation with global question (r = 0.635, P < 0.001) and good correlation with DLQI scores (r = 0.735, P < 0.001) in patients with lichen planus pigmentosus. Similarly, there was a moderate correlation of modified VIS-22 scores with global question (r = 0.607, P < 0.001) and good correlation with DLQI scores (r = 0.723, P < 0.001) in patients with melasma. DLQI correlated moderately well with global question in patients with lichen planus pigmentosus (r = 0.568, P < 0.001) as well as melasma (r = 0.547, P < 0.001). In patients with lichen planus pigmentosus, the mean modified VIS-22 and DLQI scores were higher for women, those with disease duration > 1 year, progressive disease, affected body surface area < 5% and those who were employed. In addition, the mean modified VIS-22 scores were higher for patients with lichen planus pigmentosus who were unmarried, had 1–2 body sites affected and educated till class 12, while the DLQI scores were higher for those who were married, had >2 body sites affected and educated beyond class 12. None of these differences were statistically significant for either modified VIS-22 or DLQI scores. Among patients with melasma, the mean modified VIS-22 scores were significantly higher for women (P = 0.013), those who were unemployed (P = 0.012) and educated till class 12 (P = 0.006), while the DLQI scores were significantly higher for only women (P = 0.003) and those educated till class 12 (P = 0.023).

Quality-of-life scores in patients with lichen planus pigmentosus and comparison with vitiligo and melisma

The mean DLQI score in patients with lichen planus pigmentosus was 10.9 ± 5.95, comparable to those with vitiligo (9.73 ± 6.51, P = 0.169) but significantly higher than melasma (8.39 ± 5.92, P < 0.001). Similarly, the mean modified VIS-22 score in patients with lichen planus pigmentosus (26.82 ± 11.89) was also comparable to the VIS-22 scores in patients with vitiligo (25.82 ± 14.03, P = 0.66) but was significantly higher than those with melasma (18.87 ± 11.84, P < 0.001). The mean VIS-22 scores in patients with vitiligo were significantly higher than melasma (P < 0.001), but not DLQI scores (P = 0.167). As per the DLQI scores [Figure 1], 49.6% (n = 62/125) patients with lichen planus pigmentosus had large or very large effect of the disease on life as compared to 40.7% (n = 46/113) patients with vitiligo (P = 0.168) and 29.8% (n = 36/121) patients with melasma (P < 0.001). The difference between patients with vitiligo and melasma almost reached statistical significance (P = 0.08).

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Figure 1:

DLQI scores showing the “effect of disease on life” of patients with lichen planus pigmentosus, vitiligo and melasma

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Among the DLQI domains, patients with lichen planus pigmentosus had the highest scores were for “symptoms and feelings” (1.39 ± 0.73), “daily activities” (1.26 ± 0.83) and “treatment” (1.21 ± 1.09). Lichen planus pigmentosus had a significantly higher impact on “symptoms and feelings” compared with both vitiligo and melasma (both P < 0.001). Lichen planus pigmentosus also had a higher effect on “daily activities” (P = 0.015), “leisure” (P = 0.006) and “work and school” (P = 0.024) as compared to melasma. Patients with vitiligo had higher mean scores than melasma in all DLQI domains, but the difference was statistically significant only for “work and school” (P = 0.013) and “treatment” (P = 0.013) domains [Figure 2].

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Figure 2:

Mean scores with error bars (standard error of means) of DLQI domains in patients with lichen planus pigmentosus, vitiligo and melasma (p < 0.05 * between lichen planus pigmentosus and vitiligo, † between lichen planus pigmentosus and melasma, ‡ between vitiligo and melasma)

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The highest mean scores of VIS-22 domains in lichen planus pigmentosus were obtained for “family” (2.06 ± 1.02), followed by “self-confidence” (1.42 ± 0.92), “anxiety” (1.40 ± 0.75), “attitude” (1.37 ± 0.6) and “treatment” (1.28 ± 0.73). Patients with lichen planus pigmentosus had significantly higher mean scores for “social interactions” (P = 0.02) and “depression” (P = 0.04) domains than vitiligo. In addition, the mean scores for “anxiety,” “self-confidence,” “family” and “occupation” in patients with lichen planus pigmentosus were higher than vitiligo, and lower for “attitude,” “marriage,” “treatment” and “school or college” domains, but these differences were not statistically significant [Figure 3]. Patients with melasma had a lower score in every VIS-22 domain compared to both lichen planus pigmentosus (all P < 0.05) and vitiligo (P < 0.05 for “attitude,” “self-confidence,” “treatment,” “family,” “marriage” and “social or college” domains).

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Figure 3:

Mean scores with error bars (standard error of means) of modified VIS-22 / VIS-22 domains in patients with lichen planus pigmentosus, vitiligo and melasma (p < 0.05 * between lichen planus pigmentosus and vitiligo, † between lichen planus pigmentosus and melasma, ‡ between vitiligo and melasma)

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Factors influencing the quality of life in patients with lichen planus pigmentosus

The results of univariate logistic regression and simple linear regression analysis are shown in Tables 2 and 3, respectively. Multivariate logistic regression analysis identified female gender (OR 2.97, 95% CI: 1.12–7.89, P = 0.03) to be associated with large or very large effect on life as per global question scores. As per DLQI scores, female gender (OR 2.25, 95% CI: 0.85–5.90, P = 0.09), married patients (OR 2.07, 95% confidence interval: 0.87–4.92, P = 0.09) and education higher than class 12 (OR 0.43, 95% CI: 0.17–1.08, P = 0.07) were shown to have a directional trend towards an association with large or very large effect on life, but did not reach statistical significance. Multiple linear regression analysis identified female gender (β = 2.76, 95% CI: 0.09–5.43, P = 0.04) to be associated with an impairment in the quality of life as per DLQI scores, while younger age (β = 0.16, 95% CI: 0.03–0.36, P = 0.09) and increasing disease duration (β = 0.35, 95% CI: 0.06–0.76, P = 0.09) showed a directional trend toward an association with impaired quality of life as per modified VIS-22 scores, but did not reach statistical significance.

Limitations

Since the study was conducted at a tertiary-care center, we might have included more severely distressed patients. The external validity of our results needs to be tested in other settings. In the absence of a validated disease-specific quality-of-life instrument for lichen planus pigmentosus or for pigmentary disorders in general, DLQI was used. Skin discoloration impact questionnaire, a short five-question instrument has been used in hyperpigmentary disorders by some authors; however, it is not validated and detailed information on its psychometric properties is not available.^1,21 We attempted to address this lacuna by including a modified VIS-22 as an additional quality-of-life measure, after testing its face and content validity in patients with lichen planus pigmentosus and melasma, and demonstrating a moderately good criterion validity and good convergent validity. The differences in the overall disease burden and various domains between lichen planus pigmentosus, vitiligo and melasma were better brought forth by modified VIS-22 / VIS-22 than DLQI. Further, modified VIS-22 provided richer information than DLQI regarding certain life domains such as anxiety, attitude, self-confidence, social interactions and depression, though it lacked a symptoms domain relevant to patients with lichen planus pigmentosus.