A few times each week a patient will come in to see me due to a rash of unknown cause. The rash is usually an inflamed, red skin and sometimes it’s a bit thickened and/or covered with a silvery scale. Since psoriasis often develops in adults, many people are puzzled when they come in and learn they have psoriasis and have lots of questions about the condition. I’d try to answer some of the most common questions that patients ask me about psoriasis.
What causes psoriasis? We’re not exactly sure about the cause, but we do know that it seems to have a genetic link (it often runs in families), it involves the immune system and environmental conditions seem to trigger it. The skin actually is made up of several layers and the top layer of your skin is in a state of shedding old skin cells as new skins cells are produced. This process keeps the top layer of skin relatively smooth. Psoriasis is a process in which the outter layer of skin cells grow too quickly and they stop shedding properly. This leads to a scaly build-up of skin cells that we see on the skin in affected patients. We believe that the immune system causes certain cells to enter the skin and cause the disorder.
About 40% of patients with psoriasis have family members who also have the condition.
We know that smoking appears to increase the risk of psoriasis. Certain medications can worsen psoriasis symptoms including beta blockers (used for blood pressure), lithium, and medications that we commonly use to treat malaria. Stress and anxiety may trigger psoriasis to become noticeable in people who have the genetic risk. It has also been linked with obesity and increased risk for heart disease.
What are the symptoms of psoriasis? How do I know if I have it? A medical provider may determine if you have psoriasis usually by examining your skin. There is not a blood test that can tell you if you have psoriasis but a doctor may due a biopsy of your skin if it is not clear what is causing your rash. There are several symptoms of psoriasis including:
1) Patches of skin more common on certain areas of the body such as the elbows, knees, scalp, genitals, and belly button that may be dry or red and have a white or silver scale. If you peel the scale off, the skin will likely bleed.
2) Sometimes people with psoriasis develop a form of arthritis that causes joint pain or aching
3) At times patients with psoriasis can develop finger or toenail pitting, or crumbling
What can I do about my psoriasis? Is there a cure? Unfortunately there is not a complete cure for psoriasis but there are treatment options that can substantially improve the symptoms. Patients who have severe psoriasis that is highly noticeable to other people may feel embarrassed or feel low self-esteem or anxiety due to the disorder. The treatment offered to a patient will depend on the severity of the symptoms, the area of the body affected as well as the cost and convenience of treatment and other medical conditions that the patient may have. Severe psoriasis is usually always treated by a dermatologist (skin specialist) and patients with psoriatic arthritis may be treated by a rheumatologist (joint specialist). Treatments are organized by whether they are topically applied to the skin or are taken orally or given in an injectable form.
1) Moisturizers: It is very important to keep the skin moist so that the itching and irritation caused by the psoriasis is minimized. Decreasing the itching and irritation helps to decrease the risk of scarring. Patients who are constantly scratching their skin may cause increased inflammation and risk damaging their skin and cause thickening and increase the risk for infection. Greasy ointments or thick creams work better than lotions.
2) Steroid creams or ointments: work to decrease the inflammation and redness of the skin. The most potent creams or ointments work the best for psoriasis but require a prescription. Sometimes solutions are easier to apply when patients has psoriasis of the scalp.
3) Tar: Comes from coal and has been used to treat psoriasis for years. It is commonly found in shampoos such as Neutrogena T-Gel. It seems to help decrease the amount of cells produced in the epidermis that actually causes the psoriasis. Preparations containing tar are non-prescription and over the counter and may be in the form of lotions, creams, oils or shampoos. They can stain the skin, hair and clothing but are not thought to have any serious side effects.
4) Ultraviolet Light: Patients often find that their psoriasis is better in the summer time with exposure to the sun’s ultraviolet light. Other people actually treat their psoriasis in sun tanning beds if their condition is severe. The risk of causing skin cancer must be weighed against the effects of psoriasis.
5) Calcipotriene (Dovonex): This is a cream that is applied twice a day and slows the growth of the epidermal skin cells. Another medication called calcitriol (Vectical) is similar to Dovonex and Taclonex is a medication that has calcipotriene and betamethasone (a steroid cream) combined together.
6) Tazarotene (Tazorac): This is a vitamin A derivative that is a cream or gel and is applied once a day. It can cause skin irritation so sometimes it is washed off after 20 minutes. This medication is similar to Retin-A and Differin.
7) Calcineurin inhibitors (Protopic and Elidel): are creams that are often used on the face or in skin fold areas where scarring or disfigurement may occur if high potency steroids are used.
Medications that suppress the immune system: Several medications target the immune system such as Enbrel, Amevive, Remicade, Humira and Stelara. These are usually reserved for severe forms of psoriasis because they are very expensive and are injections that are either given into the skin or muscle or into a vein over hours in the doctor’s office. Methotrexate and cyclosporine also suppress the immune system and can increase the risk of the patient developing an infection.
Soriatane is an oral medication that is derived from vitamin A and is called a retinoid. It may help reduce the symptoms of psoriasis in 3-6 months but should generally not be used in women of child-bearing age as it can cause severe birth defects.
For additional information, feel free to check out the following sites:
1) Psoriaisis.net: http://www.skincarephysicians.com/psoriasisnet/whatis.html
2) National Psoriasis Foundation: www.psoriasis.org/home/
3) American Academy of Dermatology: www.aad.org/skin-conditions/dermatology-a-to-z/psoriasis
This document is for informational purposes only, and should not be considered medical advice for any individual patient. If you have questions please contact your medical provider.
I hope that you have found this information useful. Wishing you the best of health,
Scott Rennie, DO
1) Schon, M, Boehncke, W-H Psoriasis. New England Journal of Medicine 2005; 352:1899
2) Lebwohl M. Psoriasis. Lancet 2003; 361:1197
3) Strober BE, Siu K, Menon K. Conventional systemic agents for psoriasis. A systematic review. J Rheumatol 2006; 33:1442.