Stasis dermatitis is a common inflammatory skin disease that occurs on the lower extremities in patients with chronic venous insufficiency. The excess fluid in the tissues interferes with the bloods ability to feed the tissue cells and dispose of cellular waste products. The tissue becomes poorly nourished and fragile, resulting in stasis dermatitis. The disorder is common on the ankles because there is less supportive tissue in this area. You could try venous doppler studies may reveal deep venous thrombosis or severe valve damage due to past thrombosis as yet another test to confirm the diagnosis. The tests mentioned above are more than enough.
Treatment options available are:
Elevating the ankle while resting: Compression therapy (generally accomplished by means of specialised stockings that deliver a controlled gradient of pressure). More aggressive compression can be performed by using elastic wraps; compression (Unna) boots. You must know that compression therapy must be maintained on lifelong basis.
Topical therapy: Using wet-to-damp gauze dressings soaked with water or with a drying agent, such as aluminum acetate. Topical corticosteroids are frequently used for reducing inflammation and itching in acute flares.
You did not mention if you also have ulcers but if they are present then ulcers are best treated with compresses and bland dressings (eg, zinc oxide paste) & various other dressings (eg, DuoDerm)
Oral antibiotics are useful when cellulitis (inflammation and redness) is present; topical antibiotics are useless and often cause contact dermatitis (eczema). When swelling subsides, split-thickness skin grafts (a kinds of plastic surgery) may be useful. Be wary of infection in stasis dermatitis; this becomes more problematic when using topical corticosteroids, which can make the patient more prone to infection.
So my advice to you is to either consult a good vascular surgeon or a dermatologist so that suitable treatment can be formulated for you.