The significance of dermoscopy and trichoscopy in differentiation of erythroderma due to various dermatological disorders

Abstract

BACKGROUND: The diagnosis of a patient with erythroderma may be difficult and sometimes pose a challenge for both dermatologist and pathologist. The role of dermoscopy in this area seems to be poorly investigated. There are only a few reports, with limited number of patients, describing dermoscopic features in erythroderma of various origins. To the best of our knowledge, none of the previous studies had included trichoscopic examination. OBJECTIVES: Analysis of dermoscopic and trichoscopic patterns in series of patients with erythroderma. METHODS: We retrospectively analysed 28 adult patients who presented with erythroderma between May 2016 and August 2020. Demographic data, disease course and duration, previous treatment, as well as dermoscopic and trichoscopic features were analysed. RESULTS: There were 9 patients (32.1%) with the diagnosis of mycosis fungoides, 8 patients (28.5%) with atopic dermatitis, 3 patients (10.5%) with Sézary syndrome and 3 patients (10.5%) with pityriasis rubra pilaris. The others were diagnosed with allergic eczema (n = 1; 3.6%), dermatomyositis sine myositis (n = 1; 3.6%), psoriasis (n = 1; 3.6%), actinic reticuloid (n = 1; 3.6%) and crusted scabies (n = 1; 3.6%). Characteristic dermoscopic/trichoscopic patterns have been observed in erythroderma due to crusted scabies, psoriasis, dermatomyositis sine myositis, Sézary syndrome and pityriasis rubra pilaris. Differentiation of mycosis fungoides and long-standing atopic dermatitis based on dermoscopy is difficult, as the overlap of vessel morphology, background colour and scale colour exists. Similarly, differentiation between AD and AE based on dermoscopy/trichoscopy seems to be impossible, and clinical background is crucial. CONCLUSION: Dermoscopy and trichoscopy seem to provide additional clues in the assessment of erythrodermic patient. Depending on the underlying cause, trichoscopy or dermoscopy may be more useful.