Psoriasis is a chronic skin disorder characterized by skin inflammation and flaking that occurs because skin cells grow or turnover too quickly. People affected by psoriasis may also show the following symptoms: thick, red or silvery patches of skin, tender, itchy, dry or cracked skin; thickened, ridged fingernails and toenails, stiff or sore joints (a sign of psoriatic arthritis).
Common types of psoriasis include plaque psoriasis, nail psoriasis, guttate psoriasis, scalp psoriasis, and psoriatic arthritis. Less common types of psoriasis include pustular psoriasis and erythrodermic psoriasis. Various treatments exist for psoriasis, such as light therapies, oral medications, and topical treatments, but there is no cure for psoriasis.
Researchers believe that approximately ten per cent of the population inherits at least one of the genes for psoriasis. Yet, only 2-3 per cent of the population is afflicted with the scaling disorder. It seems that you need the right "mix" of genes to develop psoriasis. If both parents possess a number of psoriasis genes, you are very likely to develop psoriasis.
Also, there are probably factors which cause the genes to become activated. It may be infections (especially strep but perhaps Candida in some people) or stress, or irritation or chemicals ( elbows and knees and hands). This likely accounts for the 'wax and wane' of psoriasis.
Topical treatments are probably the most popular treatment option. Topical steroids are the mainstay with the addition of tar products, Vitamin D analogues, Tazaratene, and Salicylic acid. Clobex Spray is the strongest steroid, and can be combined with other products. There are various topical steroid classes in different strength levels.
Light therapy has been very useful for psoriasis. Many dermatologists are switching to Narrow Band UVB. While probably not quite as effective as PUVA ( psoralen plus Ultraviolet A light) it is more convenient. UVB with tar is considered a mainstay of psoriasis treatment. Some physicians recommend pulsed dye or Excimer laser treatments for psoriasis.