There are many modalities of treatments available including, steroids and other local applications, PUVA and other phototherapies.
'Ointment and creams containing coal tar, dithranol (anthralin), corticosteroids like Topicort Desoximetasone), vitamin D3 analogues (for example, calcipotriol), and retinoids are routinely used.'
There are other measures to be taken and your doctor can tell you more about it.