Localized Pemphigus Vegetans without Mucosal Involvement.

Pemphigus vegetans is a rare variant of pemphigus vulgaris. A 62-year-old woman presented with erythematous moist vegetative plaque on the left breast and left groin. There was no mucosal involvement. Histopathological and direct immunofluorescence findings were suggestive of pemphigus vegetans. She showed excellent response to oral steroids. Literature is scarcely available on the limited involvement with pemphigus vegetans without mucosal involvement.

What was known?

Pemphigus vegetans is a rare variant of pemphigus vulgaris which commonly involves the flexures and oral mucosa.

Introduction

Pemphigus vegetans is a rare form of pemphigus vulgaris comprising only 1-2% cases.[1] Pemphigus vegetans is an autoimmune disease characterized by flaccid bullae or pustules that erode to form hypertrophic plaques involving predominantly skin flexures and mucous membranes.[2] Clinically, two subtypes are recognized: The Neumann and Hallopeau. The cutaneous lesions in the Hallopeau type begin as pustules and heal as vegetating plaques whereas those in Neumann type, with a worse prognosis, are characterized by vegetation developing during the course of Pemphigus vulgaris.[3] We herein report an unusual presentation of localized pemphigus vegetans without mucosal lesions which initially involved only the left breast, and subsequently involved the left groin during follow-up.

Case Report

A 62-year-old healthy woman presented to our dermatology out-patient department with single painful red colored elevated lesion covered with pustules on the left breast for 6 months. There was no history suggestive of any systemic involvement. There was no history of fever, any drug intake, eye or mucosal complaints, no past or family history of similar illness, no history of any topical application. On examination, a single well-defined polycyclic erythematous plaque of size 6 × 7 cm with pustules concentrated mainly at the periphery of the plaque was present on left breast. KOH mount for fungus was negative, but based on clinical appearance probable diagnosis of tinea corporis was kept, and she was started on oral Fluconazole 150 mg once a week and terbinafine cream local application twice daily for 2 weeks. On subsequent follow-up after 2 weeks, there was no improvement, but the lesion in the left breast had progressed and involved the entire left breast to form a single well-defined moist, verrucous vegetating plaque of size 8×10 cm with multiple pustules, yellow to brown colored crusts at places, and some raw oozy areas. Plaque was surrounded by a broad rim of erythema [Figure 1a]. She also developed similar verrucous lesion in the left groin on subsequent 2 weeks follow-up [Figure 2a]. Rest of the mucocutaneous examination was within normal limits. Nikolsky's sign was negative and Tzanck smear showed eosonophils, but no acantholytic cells. Gram stain for bacteria showed only mixed inflammatory infiltrate with eosinophil predominance and acid fast bacteria staining was negative. Pus culture from the pustule was sterile. Routine laboratory studies including complete blood count, C reactive protein, erythrocyte sedimentation rate, liver and renal function tests, and chest X-ray were all within normal limits. Human immunodeficiency virus serology was negative. There was no evidence of inflammatory bowel disease. Biopsy specimens were obtained from the right breast with the differential diagnosis of pemphigus vegetans, pyoderma gangrenosum.

Figure 1a

Well-defined moist, vegetative plaque studded with multiple pustules

Figure 1b

Healed hyperpigmented plaque

Patient was started on oral prednisolone 40 mg once daily with which she showed dramatic response within a week. Plaque healed completely with hyperpigmentation at 2 weeks [Figures 1b and 2b].

Histopathological examination [Figures 3a–c] showed suprabasal cleft with acantholytic cells, numerous eosinophils, intraepidermal eosinophilic abscesses, and dense inflammatory infiltrate in the dermis. As the biopsy was taken from an early pustule, that might be an explanation for the absence of hyperkeratosis and papillomatosis in the present case. Direct immunofluorescence (DIF) revealed intercellular Immunoglobulin G (IgG) deposits in the epidermis [Figure 4].

Figure 2a

Moist, verrucous plaque of groin

Figure 2b

Healed plaque

Suprabasal cleft with acantholytic cells and intraepidermal eosinophilic abscess

Suprabasal cleft with acantholysis

Increased number of eosinophils

DIF shows intercellular Immunoglobulin G (IgG) deposits in the epidermis in a fish-net pattern

Discussion

Pemphigus vegetans is characterized by verrucous intertriginous plaques with predominantly flexural involvement. Oral mucosa is invariably involved in pemphigus vegetans.[4] The histopathology in pemphigus vegetans exhibits epidermal hyperplasia, papillomatosis, and intraepidermal eosinophilic abscesses as the lesions age. Histopathology of Pemphigus vegetans seem to differ from pemphigus vulgaris by an eosinophilic response, formation of eosinophilic microabscesses and extent of vesiculation.[56] The immunofluoresence findings in pemphigus vegetans are indistinguishable from those of pemhigus vulgaris. Patient in discussion posed diagnostic challenge as she had limited cutaneous involvement, no mucosal involvement, and atypical site of presentation. We kept the possibility of pemphigus vegetans, Hallopeau type on the basis of intertriginous involvement, pustular and vegetative lesions supported, by histopathological examination with predominant eosinophilic infiltrate. All the above findings were confirmed by direct immunofluoresence showing immunoglobulin G (IgG) deposits in a fish-net pattern. Excellent response to steroids further strengthened our diagnosis. Various conditions that have to be kept in the differential diagnosis include the vegetating lesions of other bullous autoimmune skin diseases, such as bullous pemphigoid or immunoglobulin A (IgA) pemphigus, the chronic inflammatory plaques of Hailey-Hailey disease, and especially vegetating pyoderma. Differentiating pemphigus vegetans from pyodermatitis pyostomatitis vegetans is most challenging. Both diseases show similar clinical and histopathological findings, but in pyostomatitis vegetans the immunofluorescence findings are characteristically negative. Although the lesions in pemphigus vegetans can occur at any site, solitary lesion involving unusual sites like scalp, soles[7] and at skin graft recipient site[8] have rarely been described in literature. Very rarely solitary vegetating plaque mimicking pemphigus vegetans could be the cutaneous presentation for paraneoplastic pemphigus,[9] in that situation associated malignancy, severe mucosal involvement, and other criterion will be helpful in reaching the final diagnosis. Till date, to the best of our knowledge, primary involvement of the breast without mucosal involvement has not been reported.

After detailed and exhaustive work, she was being diagnosed as a case of pemphigus vegetans. She was administered oral steroid, which was tapered slowly over a period of 4 weeks. She showed excellent response; complete healing of plaques with hyperpigmentation occurred over a period of 2 weeks. Till date, even after 6 months of stopping steroid she had not shown any symptom or sign of relapse.

Conclusion

To emphasize pemphigus vegetans, although a variant of pemphigus vulgaris, can present at atypical site or show limited involvement without involving mucosa giving a diagnostic challenge. So, in routine dermatological practice resistant pustular plaque not responding to antifungal or antibacterial treatment, pemphigus vegetans can be kept as a good differential.

What is new?

In our case, the lesions were localized in the left breast and groin, without mucosal involvement.