According to the Centers for Disease Control, about 1 in 3 people will develop shingles at some point in their lives, with an estimated 1 million cases of shingles each year in the United States. The risk of developing shingles increases with age, with approximately half of all cases appearing in those who are 60 and older.
A shingles rash can appear anywhere on the body. Often, though, it’s found on the right or left side of the torso. It may also spread to the face, back, chest, or abdomen. The rash is usually quite painful, itchy, and sensitive to the touch. There may be pain at the surface of the skin a few days before the noticeable rash develops. Other shingles symptoms may include fever, fatigue, and headache.
Shingles cannot be passed from person to person. However, you can catch the virus that causes shingles from a person who has shingles. That virus is called “varicella-zoster virus.” The varicella-zoster virus, which can remain in the body in an inactive form for years, is the same one that causes chickenpox. It can become active again at any time. The virus, which lives in the nervous system, is spread by contact from fluid of the rash blisters. When it’s activated, the virus moves up the nerves to the outer surface of the skin. Once the rash from shingles crusts over, the person is no longer contagious, and the pain goes away. But for 12% to 15% of people the pain remains for months or years.
According to the American Academy of Dermatology, 7.5 million people in the United States have psoriasis. Many begin to see symptoms between 15 and 30 years of age. Another peak time for psoriasis symptoms is between the ages of 50 and 60.
Psoriasis is a chronic autoimmune disorder. Scientists have learned that a person’s immune system and genes play important roles in its development. It seems many genes must interact to cause psoriasis. People who get psoriasis usually have at least one other family member who also has it.
Unlike shingles, psoriasis is not contagious. People with psoriasis will experience periods of remission followed by flare-ups. It’s associated with rapid skin cell turnover.
Patients can get more than one type of psoriasis, and it can appear on different places on their body at different times throughout their lives. It may also appear on their torso, but the patches of dead, scaly skin typically form on the scalp, knees, and elbows. Psoriasis may also affect the fingernails and toenails. The red rash of psoriasis may be covered with silvery scales or dry, cracked skin. The affected areas may itch or burn.