The histopathological differentiation between palmar psoriasis and hand eczema: A retrospective review of 96 cases

Abstract

The histopathologic differences among palmar psoriasis (PP), hand eczema (HE), and hyperkeratotic hand dermatitis (HHD) have been poorly described. We sought to distinguish among PP, HE, and HHD on a histopathologic basis. We retrospectively analyzed the histology of hematoxylin-eosin-stained sections obtained from 96 patients diagnosed with PP, HE, or HHD. The patients were divided into 4 subgroups: PP (n=16, group A), HE without atopic or nummular dermatitis (n=41, group B), HE with atopic or nummular dermatitis (n=14, group C), and HHD (n=25, group D). Loss of the granular layer (group A 62.5%, group B 24.4%, group C 0%) was more consistent with a diagnosis of PP (P=.047) than HE (P=.002). Psoriasiform epidermal hyperplasia (group B 36.6%, group C 35.7%, group D 72.0%) favored a diagnosis of HHD (P=.01) over HE (P=.043). Limitations of this study include its retrospective nature and small sample size. Our study demonstrated that a significant difference exists in the thickness of the granular layer between PP and HE, which might be helpful in differentiating between these 2 conditions. There was no difference between PP and HHD.