Coexistence of mucous membrane pemphigoid and vitiligo.

Mucous membrane pemphigoid describes a rare heterogeneous group of chronic, inflammatory, mucous membrane-dominated, subepithelial blistering diseases that manifest a varying constellation of oral, ocular, skin, genital, nasopharyngeal, esophageal, and laryngeal lesions. Life-threatening airway obstruction and sight-threatening ocular scarring can occur in this condition, which is rarely reported in Indian literature. Vitiligo is another acquired autoimmune disorder characterized by loss of melanocytes. Vitiligo is associated with a number of disorders also considered to be autoimmune. Here we report a very rare coexistence of MMP and vitiligo, the first such report from India.

INTRODUCTION

Mucous membrane pemphigoid (MMP) is a putative autoimmune, chronic inflammatory, subepithelial blistering disease predominantly affecting mucous membranes.[1] Various basement membrane zone components have been identified as targets of autoantibodies in MMP. Mucous membranes that may be involved include the oral cavity, conjunctiva, nasopharynx, larynx, esophagus, genitourinary tract and anal canal. Vitiligo is another clinically well-characterized, chronic autoimmune skin condition. The concomitant occurrence of these two entities in a single patient is rare.

CASE REPORT

A 37-year-old male patient presented with complaints of redness and pain in his left eye since two years, painful erosions in the oral cavity since six months, and ulcers over the scrotum and right knee since two months. On ocular examination, there was congestion of the left sclera mainly on the lateral side along with a fibrotic band connecting the upper palpebral conjunctiva with the bulbar conjunctiva near the lateral canthus [Figure 1]. On examination of the oral cavity there were widespread erosions involving the inner side of lips, gingival, and labial mucosa [Figure 2]. Detailed examination revealed a single depigmented macule over the glans penis [Figure 3], which according to the patient appeared insidiously around 8 years ago and remained static. Based on the clinical features, a diagnosis of mucous membrane pemphigoid was considered. A Tzanck smear from the oral erosions, done to rule out pemphigus vulgaris, failed to show any acantholytic cells. Subsequently, the patient developed multiple tense vesicles and bullae over his left ear. In addition there was involvement of nasal mucosa, larynx, scrotal skin, perianal skin, and right knee [Figure 2]. A skin biopsy from the right ear showed subepidermal bullae and fibrosis beneath it [Figures 4 and 5]. The direct immunofluroscence of perilesional uninvolved skin showed strong linear deposits of IgG along the basement membrane zone. Detailed hematological, biochemical, and imaging studies did not reveal any evidence of malignancy. The patient was placed on a combination regimen of oral corticosteroid and daily cyclophosphamide. The long-standing depigmented macule over the glans penis did not show any evidence of atrophy, ruling out lichen sclerosus et atrophicus. Hence it was diagnosed as mucosal vitiligo and the patient was counseled regarding it.

Figure 1

MMP lesions affecting the left eye

Figure 2

MMP lesions affecting the oral mucosa, scrotum and knee (clockwise)

Figure 3

Classical vitiligo affecting the glans penis

Figure 4

Subepidermal bulla with fibrosis beneath it, black arrow demonstrates the site of blistering (H and E, ×10)

Figure 5

Subepidermal bulla (H and E, × 40)

DISCUSSION

MMP is described as a heterogeneous group of chronic, inflammatory, mucous membrane-dominated, subepithelial blistering diseases that manifest a varying constellation of oral, ocular, skin, genital, nasopharyngeal, esophageal, and laryngeal lesions. Life-threatening airway obstruction and sight-threatening ocular scarring can occur in this condition, also known as cicatricial pemphigoid, benign MMP and incorrectly as ocular pemphigoid.[1] Various basement membrane zone components have been identified as targets of autoantibodies in MMP. These include bullous pemphigoid antigen 1 (BPAg1, 230 kDa), bullous pemphigoid antigen 2 (BPAg2, 180kDa), laminin 5, laminin 6, α6-integrin subunit, β4-integrin subunit, collagen VII, and other proteins of unknown identity and/or function. Considerable variability exists in the clinical presentation of MMP.[2]

Scarring is common at non-oral sites of involvement, contributing to disease-related morbidity.[2] A multidisciplinary approach is essential in the management of MMP. Early recognition of this disorder and treatment may reduce disease-related complications. The choice of agents for treatment of MMP is based upon the sites of involvement, clinical severity, and disease progression.

Cicatricial pemphigoid (MMP) has been rarely reported in Indian literature.[3] Nayar et al. found there is an association with autoimmune diseases, both organ and non-organ-specific in a group of 34 patients with cicatricial pemphigoid suggesting a possible genetic basis for the association.[4]

Autoimmune mechanisms with an underlying genetic predisposition are the most likely causes of vitiligo, although neurohumoral and autocytotoxic hypotheses are alternative theories or contributing mechanisms. Vitiligo is associated with a number of disorders also considered to be autoimmune. Previously association of vitiligo with bullous pemphigoid either alone or along with other autoimmune diseases have been reported.[56789]

Gaspar et al. reported a case of a 68-year-old woman with vitiligo, primary hypothyroidism and cicatricial pemphigoid with severe laryngeal involvement necessitating tracheostomy.[10] A thorough search failed to reveal any other report of co-existence of these two conditions in the published literature.

MMP is a rare, difficult to treat subepidermal blistering disorder. We believe that this is the first case report of vitiligo coexistent with mucous membrane pemphigoid from India. The co-existence of these two conditions is probably is related to their common autoimmune etiology.