Diagnosis: Pemphigus Erythematosus (Senear-Usher syndrome)

CLINICAL COURSE: The patient showed no change after one month of treatment with prednisone at a dose of 60mg a day. Addition of Azathioprine (150mg/day) resulted in dramatic improvement within 6 weeks.

DISCUSSION: Pemphigus erythematosus was originally described by Senear and Usher in 1926.¹ This disease is an unusual form of superficial pemphigus with clinical, serologic and immunofluorescent findings resembling lupus erythematosus. It typically occurs in persons 17-84 years of age² but has been reported as early as age 6.³ The sex ratio is nearly equal. Facial lesions have a predilection for the malar region and truncal lesions are often confined to the v-area of the chest and interscapular region.¹ The spectrum of clinical findings includes isolated flaccid bullae or erythematous plaques surfaced with vesicles, erosions or scale. The most consistent laboratory abnormality is the presence of pemphigus antibody which is reported 89-100% of cases. ^4,5 If ANA is present it is typically in low titer and has a homogenous, or less commonly, a speckled pattern. ⁶ The histopathologic changes are identical to those seen in pemphigus foliaceus; acantholysis within the granular layer forming a subcorneal cleft and a mixed inflammatory cell infiltrate around the blood vessels of the superficial dermis. Direct immunofluorescence reveals deposition of immunoglobulin and complement within the intercellular spaces of the epidermis. In contrast to pemphigus foliaceus, approximately 80% of patients with pemphigus erythematosus also have deposition of IgG and C3 at the dermal-epidermal junction.^4,5

Pemphigus erythematosus has been seen in association with autoimmune diseases, including lupus erythematosus, myasthenia gravis and thymoma.^4,7,8 Pemphigus erythematosus may also be drug induced; penicillamine is the medication most commonly implicated.⁹

Treatment usually includes prednisone, either alone or in conjunction with an immunosuppressive agent. Dapsone has been reported to be effective in patients with a low or negative pemphigus antibody titer.¹⁰ Because this is a photo-sensitive condition, sunscreens remain an integral component to therapy.

Although pemphigus erythematosus and foliaceus have many similarities, pemphigus erythematosus can often be distinguished on clinical grounds by the restriction of the lesions to the seborrheic areas of the face and trunk. The presence of antinuclear antibodies is also suggestive of pemphigus erythematosus. The diagnosis can often be confirmed by demonstration of immunoglobulin and complement at the dermal-epidermal junction. The characteristics that help distinguish pemphigus erythematosus from foliaceus are the very features that pemphigus erythematosus shares in common with lupus erythematosus.

1 Senear FE, Usher B. An unusual type of pemphigus combining features of lupus erythematosus. Arch Dermatol Syphilol 1926; 13:761-781.

2 Amerian ML, Ahmed AR. Pemphigus erythematosus: Senear-Usher syndrome. Int J Dermatol.1985;24:16-25.

3 Andrade R. Pemphigus erythematosus in a six-year old girl. Mod Probl Paediatr. 1975;17:190-192.

4 Jablonska S, Chorzelski T, Blaszczyk M, Maciejewski W. Pathogenesis of pemphigus erythematosus. Arch Dermatol Res.1977;258:135-140.

5 Chorzelski T, Jablonska S, Blaszczyk M. Immunopathological investigations in the Senear-Usher syndrome (coexistence of pemphigus and lupus erythematosus). Br J Dermatol1968;80:211-217.

6 Amerian ML, Ahmed AR. Pemphigus erythematosus: Presentation of four cases and review of the literature. J Am Acad Dermatol 1987;16:472-480.

7 Ngo AW, Straka C, Fretzin D. Pemphigus erythematosus; a unique association with systemic lupus erythematosus. Cutis1986;38:160-163.

8 Cruz PD, Coldiron BM, Sontheimer RD. Concurrent features of cutaneous lupus erythematosus and pemphigus erythematosus following myasthenia gravis and thymoma. J AM Acad Dermatol1987;16:472-480.

9 Ruocco V, Pisani M. Induced pemphigus. Arch Dermatol Res 1982;274:123-140.

10 Basset N, Guillot B, Michel B, Meynadier J, Guilhou JJ. Dapsone as initial treatment in superficial pemphigus. Arch Dermatol1987;123:783-785.