PRP with subcorneal acantholysis: case report and review

Pityriasis Rubra Pilaris With Extensive Follicular Acantholysis Resembling Pemphigus Vulgaris: A Case Report

Pityriasis rubra pilaris (PRP) is a rare, chronic, heterogeneous, papulosquamous inflammatory dermatosis of unknown etiology. Although erythematous scaly patches characterize the classic presentation of PRP, a broad range of clinical presentations has been reported. Histologically, PRP is characterized by psoriasiform acanthosis with alternating orthokeratosis and parakeratosis and rarely small acantholytic foci. In this article, we report a patient who presented with diffuse erythroderma and extensive acantholysis mimicking pemphigus vulgaris histologically.

Recalcitrant psoriasiform dermatosis of the face: Is it related to pityriasis rubra pilaris?

BACKGROUND

There are patients with recalcitrant psoriasiform plaques that do not fit into conventional categories of facial dermatoses. Our study aims to describe the clinicopathological characteristics of several patients with a unique presentation of persistent psoriasiform facial rashes.

METHODS

This retrospective cross-sectional study analyzed clinical and histological data of known cases of recalcitrant psoriasiform dermatosis of the face diagnosed at National Skin Centre, Singapore, over 10 years.

RESULTS

There were 8 Chinese patients with mean age at onset of 29 years. Majority had pink to pink-orange well-defined plaques with dry scale (n = 6, 75%), distributed mostly on the cheeks (100%) and chin (n = 7, 88%). Hyperkeratosis, parakeratosis, preserved granular layer and psoriasiform hyperplasia were showed in all biopsies. Other common findings included subtle subcorneal acantholysis, "checkerboard" alternating ortho-/parakeratosis, vacuolated keratinocytes and follicular plugging. All patients showed little treatment response. One patient eventually developed features of type II pityriasis rubra pilaris (PRP). Our study was limited by its small sample size and lack of a pre-existing diagnostic code.

CONCLUSIONS

This recalcitrant psoriasiform facial dermatosis seems to be a distinct entity, with consistent and reproducible clinical features and a PRP-like histology, bearing some resemblance to the recently described condition-facial discoid dermatosis.

Pityriasis rubra pilaris: clinicopathological study of 32 cases from Lebanon

BACKGROUND

Pityriasis rubra pilaris (PRP) is an uncommon papulosquamous disorder of unknown etiology. Studies on this condition from our region are lacking.

METHODS

To describe the clinical and histopathological findings as well as response to treatment of all patients diagnosed with PRP at the American University of Beirut Medical Center between 1995 and 2010 and compare our findings with those published in the literature.

RESULTS

Pityriasis rubra pilaris was diagnosed in 32 patients (16 males, 16 females). Age of onset ranged between 2.5 and 70 years. The majority of patients (n=15) were classified as type I (47%) followed by type III (n=9, 28%) and type IV (n=6, 19%). Based on treatment responses, retinoids appear to be very effective in our population as all patients treated with isotretinoin or acitretin had excellent response. In addition to checkerboard alternating orthokeratosis/parakeratosis, which was observed in 31 cases, interesting features, including the presence of follicular plugging in all 21 cases in which follicles were available for examination, eosinophils in 12 cases, and focal acantholysis in three cases were observed.

CONCLUSIONS

Features of patients with PRP in our study are generally comparable to those published in the literature, with minor differences. Microscopically follicular plugging, in addition to checkerboard alternating orthokeratosis/parakeratosis, may serve as clues to PRP diagnosis. The presence of eosinophils and focal acantholysis, observed in a few cases, should not exclude PRP diagnosis.

Current knowledge in inflammatory dermatopathology

The complex and fascinating spectrum of inflammatory skin disease, and the comprehension of it, is ever expanding and evolving. During the first decade of the 21st century, numerous advances in the understanding of inflammatory disease mechanisms have occurred, particularly in psoriasis and atopic dermatitis. Continuation of this trend will assure a future in which molecular tests for biomarkers of immediate clinical relevance are used in routine patient care, not only for diagnosis but also for prognosis and management. This article focuses on selected recent or noteworthy developments that are clinically relevant for the histologic diagnosis of inflammatory skin diseases.

Psoriasiform pemphigus foliaceus: a report of two cases

Pemphigus foliaceus (PF) represents an autoimmune blistering disease characterized by the disruption of epidermal intercellular adhesion proteins. Clinical findings include superficial crusted erosions in a seborrheic distribution; however, the disease can rarely present as an exfoliative erythroderma. Histopathologic findings include acantholysis with cleavage within the granular layer. Direct immunofluorescence studies show intercellular IgG and complement deposition. We present two patients, to our dermatology department, with a previous diagnosis of psoriasis, with an exfoliative erythroderma, which ultimately proved to be because of PF based on histopathological features, direct immunofluorescence results and levels of antibodies against desmoglein 1. Both patients responded well to oral prednisone and rituximab. This variant of PF should be entertained in both the clinical differential diagnosis of psoriasiform erythroderma and in the microscopic differential diagnosis of psoriasiform epidermal hyperplasia with focal acantholysis, particularly in patients for whom the clinical history is not classic for psoriasis or for whom conventional psoriasis therapies have not proven beneficial.

A case of pityriasis rubra pilaris with associated focal acantholytic dyskeratosis complicated by Kaposi's varicelliform eruption

The clinical and histopathological diagnosis of pityriasis rubra pilaris (PRP) can be difficult because clinical findings are often subtle in early stages, and microscopic findings can overlap with those of other skin diseases. Focal acantholytic dyskeratosis (FAD) can rarely be seen in PRP and can mimic Darier's disease, Grover's disease or other disorders characterized by these histopathologic features. Kaposi's varicelliform eruption is a widespread infection due to herpes simplex virus (HSV) types 1 and 2, coxsackievirus A16 or vaccinia virus, occurring in a preexisting dermatosis; only one case has been reported in PRP. We report a patient with PRP whose biopsies showed both herpes simplex infection and FAD. A complete understanding of the mechanism behind this eruption evolved gradually, aided in great measure by the histopathologic findings.