Dermoscopic Evaluation of Hyperpigmented Lesions of the Back

Abstract

Background: Many patients complain about hyperpigmentation on their skin, especially on back and arms, due to many disorders but little is known about the use of dermoscopy as a diagnostic tool of these disorders. Objective: To assess the role of dermoscopy in the evaluation of hyperpigmented lesions affecting the back and try to find special dermoscopic features that can differentiate between different causes of hyperpigmentation. Methodology: We performed clinical and dermoscopic examination for thirty (30) patients complaining of hyperpigmented lesions on the back. Skin biopsy was taken from the lesions and examined by both light and polarized microscopy to correlate between dermoscopic features and histopathological diagnosis. Results: Thirty patients (22 females and 8 males) were recruited. We found 17 patients with macular amyloidosis (MA), 8 patients with post-inflammatory hyperpigmentation (PIH), 3 patients with lichen amyloidosis (LA), one patient with lichen simplex chronicus (LSA) and one patient with sclerodema adultorum. Dermoscopy of patients with MA showed central whitish hub surrounded with peripheral hyperpigmentation, the central whitish hub was replaced by central whitish scars in patients with LA. These findings were significant (P<0.05). dermoscopy of PIH showed diffuse hyperpigmented dots which was a significant, yet non specific finding. Conclusion: Dermoscopy can be used to diagnose primary cutaneous amyloidosis and differentiate between macular and lichen amyloidosis. Keywords: Dermoscopic Evaluation, Hyperpigmented Lesions