Test Can Be Done To Detect Psoriasis

Your doctor can often recognize psoriasis by the appearance and location of the patches on your skin, scalp, or nails. Psoriasis usually involves bright red areas of raised patches that are often covered with loose, silvery, scaling skin and are commonly located on the knees, elbows, scalp, hands, feet, or lower back.(See"Common areas of distribution of psoriasis")
Special tests are usually not needed. If it is hard to diagnose the condition by looking at your skin, your doctor may remove a small skin sample (biopsy) and send it to a lab for analysis.A contact allergy should be confirmed with a patch test.
If you have joint pain, X-rays may be taken to diagnose Psoriatic Arthritis. Blood test may help rule out other forms of arthritis.

Guttate psoriasis is a less common type of psoriasis. The small (less than 1 cm in diameter), scaly, circular elevations (papules) that occur with guttate psoriasis appear more on the trunk of the body than on the arms or legs. If you have these papules, your doctor may perform a Throat culture to determine whether Streptococcus Bacteria are present.
Sometimes a skin KOH test is done to rule out a Fungal Infection.

Common areas of distribution of psoriasis

     The lesions are usually symmetrically distributed and
     are characteristically located on the ears, elbows, knees,
     umbilicus, gluteal cleft and genitalia. The joints
     (psoriatic arthritis),nails and scalp may also be affected.

Biopsy

Biopsy is collected by doctor to send it to a lab for analysis.

Patch Test

A patch test is a method used to determine if a specific substance causes inflammation of the skin.
It is often used to test for allergens.

Psoriatic Arthritis

Psoriatic Arthritis is a type of joint disease that occurs in roughly seven percent of
people who have psoriasis.

Guttate Psoriasis

Guttate Psoriasis appear more on the trunk of the body than on the arms or legs.

Throat Culture

Throat culture are made to determine whether Streptococcus Bacteria
are present.

KOH Test

The KOH test is a procedure in which potassium hydroxide (KOH) is
used to detect fungi by dissolving human cells in a culture.