Skin Disorder-Psoriasis

What is psoriasis?
Psoriasis is an immune-mediated disease that affects the skin.It is typically a lifelong condition. No complete cure for the psoriasis.

Pathogenesis:

• Psoriasis occurs when the immune system mistakes a normal skin for a pathogen and sends out wrong signals that cause overproduction of new skin cells.
• Psoriasis is a long term(chronic) skin problem that causes skin cells to grow too quickly and makes thick, white, silvery or red patches of skin. Normally skin cells grow gradually and flake off every 4 weeks. New skin cells grow to replace the outer layers of the skin as they shed. But in psoriasis  new skin cells move rapidly to the surface of the skin in days rather than week.

Types:
Psoriasis is of 5 types;
1-Plaque
2-guttate
3-inverse
4-pustular
5-erythrodermic
 The most common type is plaque usually appears as red and white hues of scaly patches.

What are the Causes?

• Psoriasis occur when immune system overreacts, causing inflammation and flaking of skin.
• In cases are related to families.Research shows that large number of families are affected by psoriasis and it may pass from parents to children.
• Causes also include; cold dry climate, stress and dry skin. Certain medicines e.g; nonsteroidal anit-inflammatory drugs(NSAIDs).
• Smoking: especially in women.and can make it worse if somebody already have it.
• Psoriasis is not contagious.However, psoriasis has been linked to an increased risk of stroke and treating high blood lipid levels may lead to improvement.

Signs & Symptoms:

• Psoriasis can be mild, with small areas of rash. 
• When psoriasis is moderate or severe, the skin gets inflamed with raised red areas topped with loose, silvery, scaling skin.
• If psoriasis is severe, the skin becomes itchy and tender. And sometimes large patches form and may be uncomfortable. The patches can join together and cover large areas of skin, such as the entire back.

Psoriatic arthritis:
In some people, psoriasis causes joints to become swollen, tender, and painful. This is called psoriatic arthritis.
This arthritis can also affect the fingernails and toenails, causing the nails to pit, change color, and separate from the nail bed. Dead skin may build up under the nails.
Symptoms often disappear (go into remission) even without treatment and then return (flare up).

How to Diagnosis?

• Psoriasis diagnosis is usually based on appearance of the patches on skin, scalp or nails.

• KOH test can help too in ruling out fungal infection.

> No special test is needed for psoriasis.

Treatment

• First step, medicated ointments or creams+shampoo called topical treatments, are applied to the skin. If topical treatment fails to achieve the desired goal, then the next step would be to expose the skin to ultraviolet (UV) radiation. This type of treatment is called phototherapy.
• The third step involves the use of medications which are taken internally by pill or injection. This approach is called systemic treatment.

> Phototherapy in the form of sunlight has long been used effectively for treatment. Wavelengths of 311–313 nm are most effective and special lamps are available for this purpose. The exposure time should be controlled (15-30minutes) to avoid over exposure and burning of the skin.
> Vitamins A & D also helps to improve the disease condition.