If thick, scaly patches of dead skin start to appear on your body, you could have psoriasis. This is especially true if the patches are on one or more of these body parts:

  • elbows
  • knees
  • face
  • scalp
  • hands

Dry and scaly patches of skin can also signal dermatitis, eczema, or several other conditions, including skin cancer.

Often, a dermatologist can make a diagnosis by looking at the affected area and learning what other symptoms you have. Sometimes, a more thorough evaluation is needed to confirm a diagnosis of psoriasis and rule other serious conditions.

If your skin condition hasn’t been clinically diagnosed, your doctor may recommend a skin biopsy. Although the word “biopsy” is most often used when cancer is suspected, it’s more than just a test to confirm or disprove a cancer diagnosis.

A biopsy is a detailed examination of living tissue to determine the existence of a disease and its history in the body. A biopsy can also determine how far a disease may have spread.

A skin biopsy may be in order if your doctor is trying to determine what type of psoriasis you have. There are several kinds of psoriasis. Each type differs based on the look of the skin lesion, the usual location of the lesions and the possible cause or trigger of the psoriasis outbreak.

Photos of the types of psoriasis »

A skin biopsy is usually done in your doctor’s office. It’s a fairly simple procedure that begins with an anesthetic to numb the area being tested.

There are several different types of skin biopsies.

When there is a buildup of skin cells, as there is with most common types of psoriasis, a punch biopsy may be ordered. As the name suggests, the skin tissue sample is obtained with the use of a small round blade that “punches” through the skin to obtain a sample. This is similar to the way a hole punch puts holes in paper to be placed in a three-ring binder.

Other types of biopsy include:

  • a shave biopsy, which involves using a blade to slice off a small section from the outermost skin layer
  • an excisional biopsy, which involves removing the entire lesion and sometimes requires a skin graft to repair the biopsied area
  • an incisional biopsy, which involves taking only part of a large lesion

After the procedure, the area that was biopsied will be sensitive and irritated for several days.

Several days after the biopsy, your doctor will get a report from the lab that examined the skin tissue. Information from the exam is provided in a pathology report. The report contains detailed information about the tissue sample, including the presence or absence of diseases tested for by the pathologist. A pathologist is a type of doctor who studies tissue samples and interprets lab results to help diagnose diseases.

If no cancer is found, the result is known as a negative biopsy. But if cancer or another disease is found, your doctor will use the pathology report to help determine a course of treatment.

If the pathology report determines that you have cancer or any other serious disease, you may want to get a second opinion. To do this, you’ll need to make sure that the second doctor gets the microscope slides and other related material from the pathologist.

Once it’s clear what you’re dealing with, you and your doctor should discuss your treatment options. If the diagnosis is cancer, more tests will be needed to determine how far the disease may have spread. More procedures may also be needed to remove any more cancerous cells from your skin.

If you have psoriasis, a variety of treatment options are possible. These include topical lotions to reduce symptoms, or light therapy, which uses ultraviolet light to help heal damaged skin.

Psoriasis treatment »

Psoriasis is an autoimmune disease, which means your body’s immune system is acting abnormally. Psoriasis may lead to a condition known as psoriatic arthritis, which is a painful inflammation of the joints. Regardless of the extent of your illness, following your doctor’s advice will be key to maintaining good health.