FormalPara Key Summary Points

Why Carry Out This Study?

Limited qualitative research is available regarding the patient experience of lichen planus (LP), particularly for cutaneous lichen planus (CLP) and lichen planopilaris (LPP) subtypes.

This study aimed to conduct qualitative research with LP patients via two qualitative interview studies to: (1) gain insight into the patient experience of LP and (2) provide further insight into the impact of LP on patients’ emotional wellbeing, with a particular focus on CLP patients.

What Was Learned from the Study?

This study provides valuable insights into the patient perspective of the signs, symptoms, and HRQoL impacts associated with LP.

This study also confirms the importance of assessing the psychological effects of CLP as part of any HRQoL assessment in future research.

Introduction

Lichen planus (LP) is an inflammatory immune-mediated skin disease that mostly affects middle-aged adults aged 30–60 years [1, 2]. Global prevalence is estimated to be 0.5–1% of the population [3, 4] and may affect more female adults than males [5]. Diagnosis is based on clinical presentation and is typically confirmed by biopsy [6, 7]. LP can present in various forms on the body including lesions on the skin (cutaneous LP [CLP]), the scalp (lichen planopilaris [LPP]), and mucosal regions (mucosal LP [MLP]). CLP is the most common form of LP and is characterized by a subacute or chronically progressive appearance of polygonal purple papules [6]. LPP is the follicular variant of CLP and presents as active patches at the center of the scalp, along the frontal hairline and/or in the eyebrows [6]. LPP has a sexual predilection for females [4] and can also be induced by hair transplantation or cosmetic surgery [6]. If left untreated, LPP can lead to irreversible scarring and alopecia [6]. MLP presents as asymptomatic white lesions (reticular, papular, plaque-like) or painful erosive/ulcerative and erythematous lesions that most commonly affect the oral mucosa but can also involve the genitalia or conjunctiva [4, 6, 8]. An estimated 30–50% of patients with oral MLP have concomitant CLP [9]. While most instances of CLP resolve spontaneously within 1–2 years, LPP and MLP tend to be more resistant to treatment [7].

Symptoms of LP include itch, pain, and a burning sensation at the affected area [3, 10,11,12,13]. Hair loss, scaling, and scalp tenderness are also experienced in LPP patients [4] and stinging, soreness, and tenderness in MLP patients [11, 12]. In online forums (such as PatientInfo), patients with various LP subtypes describe how these symptoms can have a significant impact on health-related quality of life (HRQoL). Qualitative studies in MLP indicate that painful oral lesions affect patients’ physical functioning and daily life by impairing their ability to eat, perform oral hygiene care, and speak [11, 13, 14]. Patients’ emotional wellbeing is also affected due to the chronicity, unpredictable clinical behavior, and potentially malignant nature of MLP [14, 15]. While no qualitative studies appear to exist that explore HRQoL impacts for CLP or LPP patients, there are some quantitative studies that suggest a significant impact on aspects of emotional wellbeing, social functioning, and activities of daily living (ADL) in these patients, as indicated by patient-reported outcome (PRO) measures designed to assess HRQoL [16, 17]. The limited qualitative research exploring the patient experience of LP, particularly for the different subtypes, highlights the need for more in-depth qualitative studies in this patient population. Patient insights through qualitative research can help identify important and relevant concepts and can inform the selection of suitable PRO measures for use in clinical trials, observational studies, and clinical practice.

Several HRQoL PRO measures are available for use in specific subtypes of LP, most notably the Chronic Oral Mucosal Disease Questionnaire (COMDQ) [18] for use in MLP and the Scalpdex [19] for use in LPP. The COMDQ-26 comprises 26 items grouped into four domains: pain and functional limitation, social and emotional, medication and treatment, and patient support. A shorter 15-item version (COMDQ-15) is also available [20]. The Scalpdex comprises 23 items grouped into three domains: symptoms, functioning, and emotions. Both instruments demonstrate relatively strong coverage of key impact concepts identified in the qualitative literature and described in online forums. However, there appear to be no disease-specific PRO measures assessing HRQoL impacts in CLP. While the Dermatology Life Quality Index (DLQI) is a widely used questionnaire to assess quality of life (QoL) in patients with dermatological disorders [21], including LP [17, 22, 23], it may have its limitations in this population. Despite the instrument covering six domains of impact (symptoms and feelings, daily activities, leisure activities, interpersonal relationships, work/study, and treatment), it does not have sufficient coverage of impacts on emotional wellbeing, which have been highlighted as important to LP patients. Evidence suggests a bidirectional relationship between mental health status (i.e., stress, anxiety, and depression) and the development or course of skin diseases, further highlighting the need to understand the extent of psychological effects on patients’ HRQoL [24, 25]. Thus, further qualitative research is needed to understand the impact of LP on patients’ emotional wellbeing, with a particular focus on CLP patients. This will help inform what instrument(s) may be suitable for use in CLP.

The overall objective of this qualitative research was to explore the signs and symptoms of LP and their impact on HRQoL from the patient perspective. A further objective was to better understand emotional wellbeing impacts in CLP patients.

Methods

This research consisted of two qualitative interview studies involving concept elicitation (CE) methods to explore the patient experience of LP: (1) exit interviews with a subset of adult CLP, LPP, and MLP patients from the United States (US) enrolled in an LP clinical study and (2) independent qualitative interviews with adult CLP patients from the US and Germany to further explore the impact of CLP on patients’ emotional wellbeing. The interview studies were conducted in parallel. Figure 1 provides an overview of the research design (Fig. 1).

Fig. 1
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Overview of research design

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Compliance with Ethics Guidelines

Ethical approval and oversight for the exit interviews was obtained as part of the clinical study (clinicaltrials.gov ID: NCT04300296, EUDRACT: 2019-003588-24) from the following independent institutional review boards (IRB) and ethics committees: Advarra IRB, Columbia, Maryland, United States; Mayo Clinic IRB, Rochester, Minnesota, United States; University of Miami Human Subjects Research Office, Miami, Florida, United States; and Western Institutional Review Board, Puyllap, Washington, United States. Ethical approval and oversight for the independent qualitative interviews was obtained from Western Copernicus Group Independent Review Board (WCG IRB; reference: 20216826). The studies were performed in accordance with the Helsinki Declaration of 1964 and its later amendments, and all participants provided informed consent indicating that their data would be used for medical research purposes and that the study results may be published.

Study 1: Qualitative Exit Interviews

Sample and Recruitment

A purposive sampling method was used which included recruiting patients enrolled in an LP clinical study in the US. Patients were invited to take part in an exit interview once they had completed all treatment periods at Week 32 of the study. Participation was voluntary and patients could opt out from taking part in the interview. Patients in the clinical study had to be at least 18 years of age; have biopsy confirmed CLP, MLP, or active LPP eligible for systemic therapy based on an investigator global assessment (IGA) rating of ≥ 3 (moderate or severe); and inadequate response to topical corticosteroids of high–ultrahigh potency in the opinion of the investigator. Patients were excluded if they had LP pigmentosus, paraneoplastic MLP, LP that was predominantly a bullous variant, MLP of the oral cavity or gastrointestinal involvement requiring the patient to use parenteral nutrition or a feeding tube, burnt-out cicatricial alopecia (alopecia of Brocque), frontal fibrosing alopecia without active patches of LPP, scarring alopecia without active inflammation, or a clinical history suspicious for lichenoid drug eruption. Socio-demographic and clinical information was also collected to characterize the interview sample.

Interview Procedure

Interviews were 60 min and conducted via telephone by trained qualitative interviewers. A semi-structured interview guide, informed by a targeted qualitative literature review in LP, was used to guide the discussions. The CE section of the interview, which aimed to explore the patient experience of LP, lasted approximately 30 min and consisted of broad, open-ended questions designed to facilitate spontaneous elicitation of concepts. Participants were asked to think about their entire LP experience, from when they were first diagnosed to their present day-to-day experience, including good days and bad days with LP. Focused questions were then used if pre-identified concepts of relevance (i.e., itch and pain) had not emerged or been fully explored.

Qualitative Analysis

All interviews were audio-recorded and transcribed verbatim, with identity information redacted. Interview transcripts were analyzed using thematic analysis methods in Atlas.Ti software (version 8) [27]. Participant quotes pertaining to signs, symptoms, and impacts of LP were assigned corresponding concept codes in accordance with an agreed coding scheme. Codes were applied both deductively (based on prior knowledge) and inductively (as emerging from the data). Differences between LP subtypes were also captured.

Study 2: Independent Qualitative Interviews

Sample and Recruitment

Patients for the independent qualitative interviews were recruited by third-party recruitment agencies via referring clinicians in the US and Germany. Eligible patients had to be at least 18 years of age, have a clinician-confirmed diagnosis of CLP based on medical history, clinical signs, and results of any diagnostic technique deemed necessary (e.g., biopsy, dermoscopy, allergy test), and have mild, moderate, or severe disease based on an IGA rating of ≥ 2. Exclusion criteria were reflective of Study 1.

The target sample size was driven by principles of concept saturation (i.e., the point at which no new relevant concepts are likely to emerge with further interviews) [28]. Based on previous research, a minimum of 10 patients was deemed sufficient [29]. A quota sampling approach was employed to ensure a range of key demographic and clinical characteristics. All participants were compensated for their participation.

Interview Procedure

All interviews were 60 min and conducted via telephone by trained qualitative interviewers in the patients’ native language using a semi-structured interview guide. The CE section of the interview, which aimed to explore the impact of CLP on patients’ emotional wellbeing, lasted approximately 10–15 min. All participant-facing study documents and the interview guide were translated into German by certified translators to ensure they were appropriately adapted for the German interviews.

Qualitative Analysis

All interviews were audio-recorded and transcribed verbatim, with identity information redacted; German interviews were further translated into English. Interview transcripts were analyzed in Atlas.ti (version 8) [27], using the same thematic analysis approach as described for Study 1.

Results

Study 1: Qualitative Exit Interviews

Demographics and Clinical Characteristics

Thirteen US adults (female n = 12 [92.3%]; mean age [range] 56.5 [30–75] years) with MLP (n = 5), CLP (n = 4), and LPP (n = 4) participated in an exit interview (Table 1). Most participants had moderate LP (n = 10/13, 76.9%; MLP [n = 4], LPP [n = 4], CLP [n = 2]), based o n baseline IGA score (Table 1).

Table 1 Demographic and clinical characteristics for exit interview participants (Study 1)
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Signs/Symptoms

Participants reported ten key signs and symptoms of LP during the exit interviews: itch, pain, skin lesions, burning sensation (MLP and CLP only), hair loss (LPP only), mouth ulcers (MLP only), red gums (MLP only), tingling sensation (LPP only), dry skin (CLP only), and scarring (CLP only) (Fig. 2). Relevant quotes for each concept are shown in Table 2.

Fig. 2
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Signs and symptoms reported by CLP, LPP, and MLP participants

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Table 2 Overview of signs/symptoms reported by participants during the exit interviews (Study 1)
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The most frequently reported signs and symptoms were itch (n = 10/13, 76.9%), followed by pain (n = 7/13, 53.8%), and skin lesions (n = 7/13, 53.8%). Itch and skin lesions were experienced across all LP subtypes (MLP, CLP, LPP), while pain was only reported by CLP and MLP participants. Eight participants described areas of the body where they experienced itch, the most common being the arms, legs, and head (all n = 2). Itch was most frequently reported to be triggered by stress (n = 3/5). Pain was described as most commonly occurring in the mouth (n = 5/7) and was reported to be most frequently aggravated by eating in general (n = 4/6) or eating spicy foods (n = 3/6). Five participants described the location of their skin lesions, with the hands, feet, and legs most commonly mentioned (all n = 2). A burning sensation was reported (n = 6/13, 46.2%) by MLP and LPP participants. For MLP participants, this was experienced in their mouth (n = 4) and for LPP participants, this was experienced on their scalp when scratched (n = 2). Hair loss (n = 4/13, 30.8%), mouth ulcers (n = 4/13, 30.8%), tingling sensation (n = 3/13, 23.1%), red gums (n = 3/13, 23.1%), dry skin (n = 2/13, 15.4%), and scarring (n = 1/13, 7.7%) were also reported.

The signs and symptoms considered most bothersome to participants differed between LP subtypes, with most MLP participants reporting pain as most bothersome (n = 2/3, 66.7%), most CLP participants reporting itch as most bothersome (n = 2/3, 66.7%), and most LPP participants reporting hair loss as most bothersome (n = 3/4, 75.0%) (Fig. 2; Table 2).

Impacts on Patient Functioning and HRQoL

The impacts of LP on participants’ functioning and HRQoL are grouped into six domains: emotional wellbeing, ADL, social activities/relationships, physical functioning, work/school, and sleep. As shown in Fig. 3, participants were generally impacted by their LP, regardless of the LP subtype. Example quotes for each impact domain are shown in Table 3. Impact on emotional wellbeing was reported by all but one participant (n = 12/13, 92.3%; CLP [n = 4], LPP [n = 4], MLP [n = 4]), with feelings of embarrassment/self-consciousness (n = 7/12, 58.3%) being the most frequently mentioned, followed by frustration/annoyance (n = 6/12, 50.0%). Embarrassment/self-consciousness was most commonly attributed to the participants’ physical appearance (e.g., due to skin lesions, hair loss, mouth ulcers) (n = 7), while frustration/annoyance was most frequently attributed to itch (n = 3). Other emotional impacts included concern/nervousness/anxiousness (n = 4), bad mood (n = 3), and depression (n = 3). The impact on ADL was mostly experienced by MLP participants (n = 9/13, 69.2%; MLP [n = 5], LPP [n = 2], CLP [n = 2]) and included difficulties with oral hygiene (n = 4), food and drink intake (e.g., avoidance of spicy, hot, or hard foods) (n = 3), and changes in clothing options to cover lesions/hair loss (n = 3). The signs/symptoms most frequently reported to impact ADL were pain (n = 6) and skin lesions (n = 5). Impact on social activities/relationships (n = 8/13, 61.5%; MLP [n = 4], LPP [n = 2], CLP [n = 2]) was reported to mainly affect participants’ intimacy with their partner (n = 5) and participation in social events/activities (n = 5). Reduced intimacy was attributed to oral and genital pain (n = 3), appearance of skin lesions (n = 1), itching (n = 1), and hair loss (n = 1). Impact on physical functioning was primarily reported by MLP participants (n = 6/13, 46.2%; MLP [n = 5], LPP [n = 1]) and included difficulties chewing/swallowing when eating (n = 5) and opening/moving the mouth when speaking, smiling, or laughing (n = 4) due to pain, burning sensation, and/or mouth ulcers. Other domains less frequently mentioned were impacts on work/school (n = 3/13, 23.1%; CLP [n = 1], LPP [n = 1], MLP [n = 1]) and sleep (n = 1/13, 7.7%; CLP) (Fig. 3; Table 3).

Fig. 3
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HRQoL impact domains reported by CLP, LPP, and MLP participants

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Table 3 Overview of impact domains/concepts reported by participants during the exit interviews (Study 1)
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Study 2: Independent Qualitative Interviews

Demographic and Clinical Characteristics

Thirteen adults (female n = 8 [61.5%]; mean age [range] 53.5 [22–76] years) with CLP from the US (n = 11) and Germany (n = 2) participated in an independent qualitative interview (Table 4). All participants had either moderate (n = 7/13, 53.8%) or severe (n = 6/13, 46.2%) CLP based on their IGA score (Table 4).

Table 4 Demographic and clinical characteristics for independent qualitative interview participants (Study 2)
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Impact on Emotional Wellbeing in CLP Patients

Fifteen impacts on emotional wellbeing were discussed by participants during the interviews. Example quotes for each emotional wellbeing concept are provided in Table 5. The most frequently mentioned impacts of CLP were frustration/annoyance (n = 11/13, 84.6%) and worry/nervousness/anxiousness (n = 11/13, 84.6%), followed by feeling sad/upset (n = 8/13, 61.5%), embarrassed (n = 7/13, 53.8%), or depressed (n = 7/13, 53.8%). Most participants who felt frustrated/annoyed (n = 9/11, 81.8%) described aspects of their condition that caused this, including pain (n = 3), itch (n = 2), and flare-ups/when the disease is most severe (n = 2). Of the participants who discussed factors that caused them to feel worried/nervous/anxious (n = 8/11, 72.7%), the most frequently reported causes were visibility of skin lesions (e.g., when wearing t-shirts or shorts in public) (n = 4) and lack of improvement/the possibility of symptoms worsening (n = 4). Over half the participants who reported embarrassment also mentioned visibility of skin lesions as the cause of their embarrassment (n = 4). Reasons provided by five of the participants who experienced feeling sad/upset included acute flare-ups (n = 2), the need to dress differently to minimize the visibility of skin lesions (n = 1), having to explain persistent itching (n = 1), and lack of resolution in symptoms (n = 1). Of the four participants who provided a reason for feeling depressed, most mentioned lack of resolution/no improvement in symptoms as the cause of their depression (n = 3). Several other emotional impacts were mentioned less frequently, namely stress (n = 2/13, 15.4%), helplessness (n = 2/13, 15.4%), feeling uneasy/unsettled (n = 2/13, 15.4%), confusion (n = 1/13, 7.7%), fear (n = 1/13, 7.7%), burden (n = 1/13, 7.7%), defeat (n = 1/13, 7.7%), hypervigilance (n = 1/13, 7.7%), and guilt (n = 1/13, 7.7%) (Table 5).

Table 5 Overview of emotional wellbeing impacts reported by CLP participants during the independent qualitative interviews (Study 2)
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Discussion

While there is extensive clinical literature reporting the presentation and symptomology of LP [4, 6, 7, 12], qualitative exploration of patients’ signs, symptoms, and impact on HRQoL is limited, particularly for the different clinical subtypes. Specifically, no qualitative studies appear to exist for CLP or LPP. As such, this research sought to address this gap by exploring the experience of LP for the different LP subtypes in adult patients, including gaining a better understanding of the impact on emotional wellbeing in CLP patients.

Participants reported several signs and symptoms associated with LP, the most frequent of which were itch, pain, skin lesions, and a burning sensation. While itch was reported by participants with all subtypes of LP, fewer MLP participants reported experiencing itch compared with CLP and LPP participants. This finding aligns with previous qualitative literature that indicates that itch is not a prominent symptom of MLP [11]. By contrast, pain was only reported by CLP and MLP participants, despite the clinical literature indicating that pain is also a key symptom of LPP [30]. The lack of LPP participants reporting pain in this study could be due to the small sample size; as such, this finding should be interpreted with caution. No CLP participants spontaneously reported experiencing a burning sensation in the exit interviews, which aligns with the literature that burning sensation is a more prominent symptom of LPP and MLP [4, 11, 31]. However, this finding should not be taken to indicate that CLP patients do not experience a burning sensation, as pre-study recruitment discussions with participants indicate that some CLP patients may experience this symptom and, where this concept was assessed, conceptual saturation may not have been met due to the small sample size of CLP patients in the exit interview sample. Other signs and symptoms that were reported by only one subtype of LP included hair loss and a tingling sensation on the scalp, both of which are recognized in the clinical literature as symptoms associated with primary cicatricial alopecias like LPP [4, 32, 33]. Further, two thirds of MLP participants described the appearance of red gums, which has been previously documented as a clinical sign of oral LP [34].

These signs and symptoms were also reported to have a significant impact on participants’ HRQoL. Consistent with previous literature [11, 13, 14], MLP participants reported that painful oral lesions affect physical functioning and ADL by impairing their ability to eat, perform oral hygiene care, and move or open their mouth to speak, laugh, or smile. Oral discomfort was reported to be triggered or intensified by spicy, hot, or hard foods/liquids, leading to dietary alteration and avoiding activities in most MLP participants [11, 35, 36]. Further, some CLP and LPP participants described how concerns about the visibility of skin lesions/hair loss had led to changes in their clothing habits to hide affected areas of the body. While this finding was identified in a previous study that implemented the DLQI in patients with CLP [16], the current studies provide direct qualitative evidence from the patient perspective. Notably, across the LP subtypes, participants reported substantial impact on their emotional wellbeing, which they attributed to various aspects of their condition. These included (but were not limited to) feelings of frustration/annoyance primarily due to itch, and embarrassment associated with their physical appearance. This is reflective of previous literature that LP has a significant impact on patients’ psychological wellbeing [15,16,17]. LP was also reported to impact social functioning across the LP subtypes, with participants mentioning reduced intimacy and avoidance of social activities due to their symptoms. While impaired sexual function has been previously documented in relation to vulvovaginal MLP [37, 38], in the current study, participants across LP subtypes described aspects of their condition that affected intimacy with their partner, including oral or genital pain (MLP), appearance of skin lesions and itching (CLP), and hair loss (LPP). The present study supports findings from previous literature that work/school activities are less frequently impacted in LP patients [11, 16]. Impaired sleep, which was only mentioned spontaneously by one CLP participant, has been documented to be a significant impact in patients with dermatological disorders, including oral MLP [39], due to itch, pain, and reduced psychological wellbeing [40]. While these findings largely align with the literature, they add an important contribution in that, previously, there were no qualitative insights in the literature describing the patient experience of CLP and LPP from the patient perspective, and limited qualitative insights from the MLP patient perspective.

This research also specifically focused on aspects of emotional wellbeing in CLP patients, given the importance of emotional impacts in LP and the absence of disease-specific instruments available in CLP. CLP participants in both studies reported several impacts on their emotional wellbeing, including (but not limited to) frustration/annoyance, worry/nervousness/anxiousness, embarrassment, and depression. Such findings are consistent with previous quantitative literature that CLP has a significant impact on emotional wellbeing [16]. However, the current study provides a more in-depth understanding of the ways that CLP patients’ emotional wellbeing is impacted from the perspective of patients themselves. In particular, participants described that the cosmetic appearance of skin lesions caused them to feel embarrassed about their appearance and anxious or nervous about the visibility of skin lesions, particularly when wearing t-shirts and shorts in public. Participants described feeling depressed about the lack of resolution in symptoms and expressed worry that their symptoms may not improve or could worsen. Persistent or severe symptoms were reported to cause participants to feel frustrated or annoyed with their condition. While several participants reported sadness, the reasons were variable (e.g., severity of symptoms, lack of symptom resolution, and having to change clothing habits to cover lesions). These findings confirm that CLP significantly impacts patients’ psychological wellbeing, in addition to other domains of HRQoL (as previously described). As such, when considering how best to assess HRQoL in CLP populations, capturing the emotional impacts of CLP should also be considered. For example, the DLQI would not be considered appropriate as a standalone measure for assessing HRQoL in CLP patients as it lacks coverage of important impacts on emotional wellbeing.

CE methods used in qualitative interviews remain the gold standard for providing in-depth understanding of the patient experience. Such findings are paramount for identifying concepts that are relevant and important to patients and can help inform selection of appropriate outcome instruments in clinical research [41]. For the exit interviews, one benefit is that the evidence generated was obtained during a time when participants were actively monitoring their condition as part of an LP clinical study and therefore it is assumed that participants would have been more acutely aware of their disease experience.

Some limitations of this study should also be noted. An important limitation is the inclusion of relatively few participants who may not be representative of a wider population. Although the exit interview sample included participants with a range of LP diagnoses, the sample size within each subtype was relatively small and there was a greater proportion of participants with moderate LP, presenting a limitation in the analysis and interpretation of these data. Further, participants were selected based on a clinician-confirmed primary diagnosis of CLP, MLP, or LPP and no pre-defined quotas were used to target patients with specific regions of the body where quality of life may be more greatly affected (e.g., nail involvement, genital regions). However, considering the rarity of specific presentations like nail involvement, the inclusion of these participants may not generalize to the wider LP patient population. To our knowledge, this is the first qualitative study exploring patients’ perceptions of the signs, symptoms, and impact on HRQoL associated with CLP and LPP subtypes. Therefore, despite the small sample size, this research not only adds to the qualitative literature available in MLP [11, 13,14,15], but also provides preliminary insights into the experience of CLP and LPP from the patient perspective. A further limitation is that participants for the exit interviews were predominantly female; however, this is reflective of the literature, which suggests that LP may affect more females than males [5]. Additionally, itch and pain were specifically probed for during the exit interviews, which may over-represent the prevalence of these concepts compared with others identified in this research.

Conclusion

The results of this qualitative research contribute to the literature by providing insights into the adult patient experience of LP (namely the signs, symptoms, and impact on HRQoL) across three LP subtypes. This research also highlights that in addition to assessing key symptoms of LP, consideration should be given to the assessment of impact on HRQoL in future LP research; in particular, highlighting the importance of considering impacts on emotional wellbeing when selecting instruments for the assessment of HRQoL in CLP patient populations.