Challenges and Considerations in the Diagnosis and Management of Lichen Planus Pemphigoides

Dear Editor, Lichen planus pemphigoides (LPP) is an autoimmune disease associated with autoantibodies against collagen XVII. It was initially described by Kaposi in 1892 as a variant of lichen planus. Its exact prevalence is unknown, although it is estimated to be one case per 1,000,000 patients. It occurs more frequently in adult women; however, in children and teenagers it is more frequent in males.[1] Current data is scarce, with only 78 reports until 2010.[2] We present the case of a 33-year-old female, with no previous clinical history, who reported a year of a pruritic and scaly skin rash in the lower extremities, later expanding to the upper limbs and trunk. One week later she presented tense blisters in upper and lower extremities along with extension of previous eczematous lesions. Upon arrival, she had multiple papules and generalized violet plaques, involving > 50% of the total body surface, along with tense serous bullae on the back of the hands and anterior aspect of both legs [Figure 1]. Dermoscopy identified Wickham’s striae. Blood work showed a negative infectious profile, liver and kidney were within standard limits. A skin biopsy of a bullous lesion on the right leg revealed a subepidermal blister with an empty cavity and lymphocytic infiltrate with melanophages in the dermis [Figure 2]. The direct immunofluorescence (DIF) revealed linear deposition of C3 [Figure 3] and C1q in the basal membrane (BM); supporting the diagnosis of lichen planus pemphigoides. She received treatment with topical clobetasol and prednisone at 30 mg/day along with doxycycline 100 mg every 12 hours with great clinical improvement.Figure 1: Tense serous bullae on intact skin over the dorsum of the handFigure 2: Hematoxylin-eosin 10×Figure 3: IFD: linear C3+ in MBThe exact pathophysiology of this disease is unknown. The release of antigens in the basal membrane generates an antibody-mediated immune response leading to a complement-mediated attack that will eventually cause a split at the dermoepidermal junction forming a blister.[2] Clinically, it presents as lichenoid papules and plaques, associated with the formation of tense blisters and intense itching. Blistering follows the appearance of lichenoid skin lesions on previously unaffected skin.[1] It is most frequently located in extremities.[3] Mucosal involvement is uncommon.[1] There is no clear association established to LPP. Most cases are considered idiopathic; however, some theories report association with viral infections, neoplasms, and medications.[2,3] Bullous lichen planus (BLP) can be differentiated from LPP by its clinical presentation and histologic findings; where formation of blisters on lichen planus lesions is linked with the presence of immunoglobulins and complement (C3+) in basal membrane, along with circulating anti-BP180 autoantibodies in LPP, different to BLP where there is no autoantibodies present.[2,4] Histological findings show interface dermatitis and vacuole changes in the dermoepidermal junction along with the presence of apoptotic keratinocytes known as Civatte bodies.[1] Treatment includes both high-potency systemic and topical steroids. Other alternatives described in refractory cases are acitretin or dapsone.[3] Successful cases have also been reported with isotretinoin, tetracyclines, cyclosporine and methotrexate.[1,5] This entity should be considered as a diagnostic and therapeutic challenge due to its low prevalence and lack of clinical consensus regarding its management. Statement on consent for publication I give consent for the publication of identifiable details, which include photographs, case history and details within the text to be published. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.