Histological diversity in hyperkeratotic flexural erythema—Beyond granular parakeratosis?

The term ‘hyperkeratotic flexural erythema’ (HFE) has been used synonymously with granular parakeratosis (GP), to describe a scaly, typically intertriginous rash associated with contact factors such as benzalkonium chloride. However, clinical HFE can occur without the classical GP histological pattern. We reviewed skin biopsies from 10 patients with clinically diagnosed HFE. A progression of histopathological features is suggested. The absence of histological GP should not exclude the clinical diagnosis of HFE when there is a high index of suspicion.