Psoriasis cause unknown but many treatments available

psoriasis photo

Psoriasis is a disease affecting your skin. It causes thick, red patches with silvery scales that can be itchy or sore. These patches usually appear on your elbows and knees, scalp, palms and feet, back, and face, but can also develop on other body parts. Certain patients may even develop a form of arthritis known as psoriatic arthritis.

But what causes psoriasis? Researchers still do not know the exact answer, but do know that the disease is not contagious. Instead, your immune system and genes play an important role. It’s not just any genes, though. Scientists believe you must inherit the “right” combination of genes and then be exposed to a specific “trigger” in order for you to develop psoriasis. These are some common triggers:

  • A stressful event;
  • Strep throat;
  • Taking specific medications (i.e. Lithium, or antimalarial medication);
  • Cold, dry weather; and
  • A cut, scratch, or bad sunburn.

There are various forms of psoriasis and your symptoms depend on which type you have. Some of the more common types and their symptoms are:

Plaque psoriasis

  • Raised, reddish patches (i.e. plaques) that may be covered with a silvery-white coating (i.e. scale);
  • Patches may appear anywhere on the skin, but usually on the knees, elbows, lower back, and scalp;
  • Patches may be itchy, and scratching them usually causes them to thicken;
  • Patches vary in size and may appear separately or joined together; and
  • Nail problems (i.e. pits in nails, crumbling nails, or nails falling off).

Guttate psoriasis

  • Small, red spots that are usually on the trunk, arms, and legs (also can appear on the scalp, face, and ears, or entire skin);
  • Spots usually appear after an illness, most commonly strep throat;
  • Spots may clear up without treatment after a few weeks or months; and
  • Spots may appear in areas where there was plaque psoriasis.

Pustular psoriasis

  • Red, swollen skin dotted with pus-filled bumps, which usually only appear on the palms and soles;
  • Bumps are sore and painful; and
  • Pus-filled bumps will dry, leaving brown dots and/or scale, but while the bumps cover the body you may also have
    • Bright-red skin;
    • Feel sick and exhausted;
    • Experience fever or chills;
    • Have severe itching;
    • Have a rapid pulse;
    • Lose your appetite; and
    • Have muscle weakness.

Inverse psoriasis

  • Smooth, red patches that look raw and only develop where skin touches skin (i.e. armpits, groin, genitals, buttocks, and under the breasts); and
  • Very sore skin in the affected areas.

Erythrodermic psoriasis

  • Skin appears burned and most (or all) of it turns bright red;
  • Body can’t maintain its normal temperature (98.6°F) and you get very cold or hot;
  • Heart beats too fast; and
  • Severe itching and pain. If someone appears to have erythrodermic psoriasis, it’s a life-threatening emergency and they should be taken to a hospital immediately.

While anyone may develop psoriasis, there are specific risk factors which can increase your chances of doing so:

  • Family history: having one or both parents with psoriasis greatly increases your risk of developing it yourself;
  • Viral and bacterial infections: HIV patients are at increased risk than persons with healthy immune systems, and children and young adults who have repeated infections (especially strep throat) are also at a higher risk;
  • Stress: high stress levels may impact your immune system and increase your risk of developing psoriasis;
  • Obesity: excess body weight increases your risk. Also, plaques tend to form in skin creases and folds; and
  • Smoking: smoking tobacco increases your risk and may also increase the severity of your psoriasis if you develop it.

Treatment options

Treatment for psoriasis aims to reduce the inflammation and clear the skin, and can be divided into three types – topical treatments, phototherapy, and systemic medications.

Topical treatments

These remedies are used to treat mild to moderate psoriasis and include:


Phototherapy involves the use of natural (sunlight) or artificial ultraviolet light.

Systemic medications

These remedies are typically reserved for severe or resistant psoriasis, and may be used for only short periods because of severe side effects.

About the Author

Julie Kaplan, Pharm. D.
Julie Kaplan is a licensed pharmacist in Virginia and the District of Columbia. She received a Bachelor’s of Arts in English from The College of William and Mary and a Doctor of Pharmacy from Virginia Commonwealth University. She has experience in patient communication from working as a retail pharmacist.