Grover’s Disease Treated With Total Skin Electron Beam Radiotherapy

Abstract

Persistent Grover’s disease can cause significant symptoms of pruritus thereby decreasing quality of life. Many patients undergo successful conservative management of their disease; however, a subset of patients is recalcitrant despite multiple lines of therapy. Accordingly, we present, to our knowledge, the first reported case of recalcitrant Grover’s disease treated successfully with radiotherapy.

INTRODUCTION

Grover’s disease is an acantholytic dermatosis of unknown etiology, characterized by a clinical syndrome of pruritus and papulovesicular rash typically of the torso and upper extremities.¹ Histologically, Grover’s can resemble pemphigus, Darier’s, and Hailey-Hailey disease.² While typically transient and self-limited, persistent Grover’s disease has been described as early as 1976.³ When persistent, pruritus can be significantly life altering, and in rare circumstances, the disease is recalcitrant to therapy. Radiotherapy has been successfully described for histologically similar entities such as Hailey-Hailey and Darier’s disease.^4,5 Accordingly, we present to our knowledge, the first case of persistent Grover’s disease treated with radiotherapy.

REPORT OF A CASE

A 74-year-old male with past medical history of diabetes with end organ damage and chronic obstructive pulmonary disease presented with diffuse pruritus and a papulovesicular rash over the neck, upper torso and arms for a duration of 3 years. Skin biopsies showed acantholytic dermatosis compatible with excoriated type Grover’s disease (Figure 1). Since diagnosis, multiple therapies had failed including: topical steroids, prednisone, antihistamines, acitretin, UVB phototherapy, and photodynamic therapy. Given his recalcitrant disease, total skin electron beam radiotherapy was pursued for palliation of his constant, severe, and debilitating pruritus.

FIGURE 1.

Grover’s Disease. H&E slides of acantholytic dermatosis consistent with Grover’s disease from 2 consecutive biopsy specimens.

In order to assess the efficacy of radiation, a limited “test” patch of focal electron radiation over his left upper chest was performed. The patient underwent radiotherapy to a total dose of 20 Gy in 12 treatment fractions with 6 MeV electrons prescribed to the depth at which 90% of maximum dose delivered with 0.5 cm bolus. At one month follow up the patient described “markedly improved” pruritus.

In light of his significantly improved pruritus within the test radiation field, we then planned treatment covering his neck, upper torso and arms. We administered radiation therapy to the upper body (blocking the head superiorly and lower extremities interiorly) with a 6-field total skin electron technique to a total dose of 20 Gy in 20 fractions with 6 MeV electrons. At 4 weeks posttreatment, the patient noted near complete relief of pruritus. At 5 and 12-months follow up, the patient described complete relief of his pruritus and on clinical exam there was resolution of his papulovesicular rash with no use of topical or systemic agents in the interim. However, at 18 months, the patient again developed return of symptoms and was treated with a second course of radiotherapy (same dose and technique) again with successful relief of symptoms with ongoing follow up of 9 months.

DISCUSSION

To our knowledge, this is the first reported case of Grover’s disease treated successfully with radiotherapy. The mechanism of action of ionizing radiation in a therapeutic sense for benign dermatoses is unknown, however, some authors have indicated that perhaps radiotherapy interrupts a dysregulated immune reaction.⁶ Accordingly, radiotherapy has been successful for other recalcitrant benign dermatoses.^4,5 For instance, Narbutt et al described a case of recalcitrant Hailey-Hailey disease of the bilateral axilla treated with 7.5 MeV electron beam irradiation to 20 Gy in 10 fractions with complete resolution of symptoms at 10 months.⁴ Similarly, Kittridge et al reported a case of severe, recalcitrant Darier’s in the bilateral mammary fold treated similarly with 20 Gy in 10 fractions. The patient had a complete response at last follow-up (18 months).⁵ We extrapolated from these experiences and were able to successfully deliver a safe and meaningful dose of radiotherapy to our patient.

At 27 months follow up, our patient had a significant clinical response, however, the duration of response remains unknown. In conclusion, radiotherapy appears to be a promising last resort for patients with persistent Grover’s Disease (acantholytic dermatosis) in which conventional treatment options have been exhausted.