Single-plaque psoriasis: a single-clue diagnostic challenge

Abstract

Introduction

Psoriasis is a chronic, common immune inflammatory condition of the skin, affecting 2-3% of the population, with regional variability. Classically, psoriasis presents as one of the following types: plaque, guttate, inverse, pustular or erythrodermic psoriasis. Typically, the patient will present with several symmetric psoriatic plaques on typical areas of the body, leading the clinician towards the diagnosis of psoriasis.

Case report

The present case report series focuses on an atypical presentation of psoriasis noted in 2 patients who presented to our office with a single large, erythematous plaque located on the lower leg. Due to poor response to previous treatment, a biopsy was performed and upon analysis, revealed a diagnosis of psoriasis. The lesions showed significant improvement under local therapy.

Conclusion

In spite of significant research on such a common and seemingly well-understood dermatosis, the present case reports plead for further study with regards to atypical presentations of psoriasis.