001Ankle rashes and Introduction

Introduction - Just knowing the site of a biopsy can be very useful in arriving at a range of possible diagnoses. Some additional clinical information on the nature of the rash, whether red scaly or red non scaly, whether it blanches and the treatments already tried , can provide the context for a correct diagnosis with good clinical correlation.

So if you are given the site of a biopsy you can view potential diagnoses at this website in case you might miss them.

Ankle Rashes -- Dependency means that conditions such as stasis dermatitis, capillaritis and vasculitis tend to occur around the ankle. Stasis dermatitis with an associated Pigmented Purpuric dermatosis is quite common. If there is marked venous incompetance then oedema and lipodermatosclerosis with associated scarring of atrophe blanche often eventuates.Bleeding around the ankle is seen in Capillaritis and in frank Vasculitis.

Solar keratoses and SCC in situ are also common on the lower legs particularly in women. Chronic rubbing of stasis dermatitis will result in lichenification or thickening of the skin giving Lichen Simplex Chronicus. This is usually on the shin but may extend across the ankle anteriorly on to the dorsum of the foot.
Stucco keratoses are inherited small scaly papules around the ankles that histologically resemble seborrhoeic keratoses. Flegel's disease can look similar but the papules may be pigmented.


Stasis dermatitis  Histology Dermnet

Lichen simplex chronicus   Histology Dermnet

Pretibial myxedema    Histology Dermnet

Granuloma annulare   Histology Dermnet

Lipodermatosclerosis (Atrophie blanche)   Histology Dermnet

Bleeding into the Skin at Ankle-

Solar lesions

SCC in Situ Bowen's Disease

Amelanotic Melanoma Acral

Stucco keratoses

Flegel's disease