Pigmentation of lower limbs: Contribution of haemosiderin and melanin in chronic venous insufficiency and related disorders.

Background: To determine the composition of skin pigmentation in chronic venous insufficiency (CVI) and other less common vascular conditions of lower limbs.

Methods: Forty-five skin biopsies were obtained from 17 patients. Samples were taken from pigmented regions and compared with control non-lesional samples from the same patient. Perl's Prussian Blue was used to identify haemosiderin and Schmorl's for melanin.

Results: Seven patients presented with CVI, one with concurrent livedo vasculopathy (LV). One patient had LV only. Two patients had acroangiodermatitis (AAD). Six patients had post-sclerotherapy pigmentation (PSP), one with concurrent post-inflammatory hyperpigmentation (PIH). One patient had PIH only. The predominant pigment in CVI samples was haemosiderin. C5-C6 patients showed increased epidermal melanin. LV, AAD, and PSP samples showed dermal haemosiderin but no increase in epidermal melanin. PIH samples showed prominent epidermal melanin whilst no haemosiderin was detected.

Conclusion: The predominant pigment in CVI and other vascular conditions was haemosiderin. Melanin was present in later stages of CVI (C5-C6) and in PIH.