Frequently Asked Questions about Psoriasis

Q: Cortisone creams have been controlling my psoriasis for years, but they seem to be less effective now. Why is this happening? A: With continued use, a resistance develops to the therapeutic effects of cortisone creams. When this occurs, the creams become progressively less effective and stronger formulations are needed to achieve comparable results.

Combination therapy, using cortisone creams with other topical therapies, such as Dovonex or Tazorac, can help minimize the side effects of long-term cortisone use, such as thinning of the skin, or reduction in effectiveness.

Q: I have psoriasis. My fingernails are discolored and separated from the nail beds. Should I be treated for fungus?
A: Fifty percent of persons with psoriasis have nail involvement. This usually involves pitting on the nail surface or discoloration, lifting and/or thickening of the nail. Prior to treatment with antifungal medication, your dermatologist should test the nails for fungus.

If this test is positive, then antifungal therapy most likely will be effective. If the test is negative, then it may be that your nail condition is due to psoriasis. Antifungal treatments will not be effective in such cases.

Q: What are the risks involved with PUVA therapy?
A: PUVA is the combined therapy of psoralen and ultraviolet A (UVA) rays. The psoralen usually is given in pill form about 30 to 60 minutes before UVA exposure. It also can be administered as a topical solution, that is, "painted" onto the lesions or added to a bath before the light treatment.

Long-term PUVA therapy has been associated with an increased rate of skin cancer, especially non-melanoma, like squamous cell carcinoma, or basal cell carcinoma, as well as melanoma. Individuals who have had many PUVA treatments should be examined for skin cancer on a regular basis.

Psoralen, when ingested orally, causes sensitivity to UVA rays. This makes the treatments more effective. However, because sensitivity persists for 24 hours after ingestion, further sun exposure should be limited. In addition, eye protection is essential and special UV-protective glasses should be worn for a day. Periodic eye examination is recommended.

Q: I recently started new blood pressure pills. Shortly thereafter, I was diagnosed with psoriasis. Is there any connection?
A: There are several known medications that can trigger psoriasis. Two classes of blood pressure medications—beta-blockers and angiotensin-converting enzyme inhibitors (ACE inhibitors)—have been associated with the development of psoriasis and exacerbation of existing disease.

Beta-blocker eye drops, such as those used to treat glaucoma, can cause psoriasis to occur in predisposed individuals as well. Lithium, a drug used mainly for bipolar disorder (formerly called manic-depressive disorder), is another known inducer and exacerbator of psoriasis.

If you are taking any of these medications, you should discuss this with your doctor, who may be able to switch you to an effective alternative drug.

Q: My rheumatologist diagnosed psoriatic arthritis, but I don't have psoriasis. Is this possible?
A: Yes. About one in seven persons with psoriatic arthritis do not first show evidence of psoriasis on their skin. The diagnosis may be somewhat elusive, but is aided by a positive family history of psoriasis or evidence of pitting in the fingernails.

Psoriatic arthritis typically develops between ages 35 and 45. Earlier onset is associated with more severe disease and joint destruction. Your rheumatologist probably has performed some tests to check for other forms of arthritis, such as rheumatoid. Treatment varies according to disease severity.

Q: I have been on methotrexate for a while and my psoriasis is very well controlled. My liver function tests have all been normal. Do I still need a liver biopsy?
A: A liver biopsy is recommended in all patients on methotrexate after about 1 to 1.5 grams of the medication have been ingested, regardless of normal blood tests. However, the biopsy may need to be done sooner if signs of liver irritation appear. This is recommended because liver damage can occur even with normal blood tests. It is important to diagnose liver damage early, while it is reversible.

Q: What's new in psoriasis therapy?
A: There is much interest and continuing research in the field of psoriasis. One new treatment, anti-CD 11a injection, is in the final stages of testing. Preliminary data shows it to be quite promising for the safe treatment of severe psoriasis.

Q: Why should I take folate while receiving methotrexate therapy?
A: Folate, or folic acid, counteracts the effects of anemia produced by methotrexate. It also reduces the nausea associated with this therapy.

Publication Review By: Stanley J. Swierzewski, III, M.D.

Published: 31 Aug 2000

Last Modified: 01 Oct 2015