However, other types can cause different lesions, and symptoms do not affect only the skin.
For most people, symptoms are cyclical. They appear for a few weeks during a flare and then ease or disappear for a while.
There are many different types of psoriasis, including plaque psoriasis, nail, scalp, guttate, inverse, erythrodermic, and pustular psoriasis. Psoriasis can also lead to a number of complications.
Read on to find out more about how to recognize some of the types of psoriasis.
Plaque psoriasis causes red scaly patches with a silvery sheen on the skin.
A person with plaque psoriasis is likely to experience the following:
- Raised, inflamed, red lesions or plaques that may be covered in a silvery white scale.
- They can appear anywhere in the body but the elbows, scalp, knees, and lower back are common locations.
- Plaques are typically itchy, sore, or both.
- The skin around the joints may crack and bleed.
Inverse psoriasis tends to appear in skin folds, and it is more common among people who have excess weight.
- Patches of skin become inflamed, bright red, and smooth, but there is no scaling.
- The lesions can become itchy or painful.
- Symptoms can become worse if the skin rubs together or if there is sweating in the folds.
- It is most likely to affect the armpits, the groin, the skin between the buttocks, the skin under the breasts, and belly folds if a person has these.
Nail psoriasis can cause ridging, pitting, and weakening of the nails.
Nail psoriasis affects the finger and toenails. It may happen with plaque or another type of psoriasis.
If symptoms are severe, it can become hard to use the hands and feet, according to the American Academy of Dermatology.
Here are some of the features.
- Yellow-red nail discoloring may look like a drop of oil or blood under the nail plate.
- Pits develop in the nails.
- Lines appear across the nails, usually from side-to-side rather than from top-to-bottom. The lines stem from an inflammation of the cells.
- White areas appear on the nail plate.
- The skin under the nail thickens.
- The nail loosens, and it may separate, lift, and detach from the finger or toe. Where the nail separates, a white area may develop on the skin below, starting at the nail's tip and extending downwards. Infection may develop in the skin under the nail.
- The nail may crumble as it weakens.
- Small black lines may appear, running from the tip of the nail to the cuticle. This happens when tiny blood vessels bleed between the nail and the skin under the nail.
- The "half moon" at the base of the nail may become spotted. It can turn red if the capillaries under the nail are blocked.
People with psoriatic arthritis can experience nail changes if the arthritis affects their fingers.
The changes can look like the signs of a fungal infection. Sometimes there is a fungal infection, known as onychomycosis, but this is not always the case. Sometimes a bacterial infection can result in the skin folds around the nail.
This is sometimes known as teardrop psoriasis or raindrop psoriasis. Lesions appear on the skin, but they look different from those in plaque psoriasis.
- Plaques are usually small, no more than half-an-inch in diameter.
- Plaques are fairly widespread and may develop anywhere in the body, except the soles of the feet and palms of the hands. Common areas include the chest, arms, legs, and scalp.
- Some signs and symptoms of nail psoriasis may also be present.
Guttate psoriasis usually occurs after a strep throat infection, and it is more common among teenagers and children. It may disappear and not come back, but some people eventually develop plaque psoriasis.
In scalp psoriasis, skin changes occur on the head and around the hairline.
Scalp psoriasis can occur alone or together with plaque psoriasis.
- Red patches of skin appear, covered with thick, silvery-white scales.
- These may or may not itch.
- It often affects the back of the head, but it can occur across the scalp, or on other parts of the head.
- In some cases, hair loss can occur.
This is less common than the other kinds of psoriasis.
There are three main types, and they affect different areas of the body. In pustular psoriasis, the lesions contain pus, which is made up of white blood cells.
Von Zumbusch psoriasis
- Pustules develop rapidly across a wide area of skin.
- The pus is not infected
- Within 2 days, the pustules usually dry and peel off, leaving the skin shiny and smooth.
- Pustules may appear in cycles of weeks or even a few days
- At the start of a cycle, the individual may experience fever, chills, fatigue, and weight loss.
Palmoplantar pustular psoriasis
This type affects the hands and feet. It may happen alone or alongside another type of psoriasis.
The following can happen:
- Pustules appear on the soles of the feet or the palms of the hands.
- The pustules develop into round, brown, scaly spots that eventually dry and peel off.
- Cycles of recurrence may occur every few weeks or even within days.
- The person may have difficulty walking or using their hands.
- Pustules appear on fingers, toes, or both.
- The pustules burst, leaving bright red areas that may ooze or become scaly.
- Sometimes, the person will have symptoms of nail psoriasis.
This is the least common form of psoriasis, but it can be life-threatening if the person does not receive treatment.
- There is widespread inflammation, and the whole body can become covered with a fiery red rash.
- There is usually intense itching, burning, and pain.
- Widespread exfoliation, or shedding of skin, occurs. At this time, itching, burning, and swelling is more severe.
- The body becomes more susceptible to losing proteins and fluid. This can result in dehydration and heart failure.
- As the skin cannot function effectively, the person's temperature may fluctuate, so that they become too hot or too cold.
Other symptoms include:
- chills, fever, and a feeling of being unwell
- muscle weakness
- a rapid pulse
If a person develops a red, fiery rash across the skin, it is important to seek urgent medical treatment. The complications of erythrodermic psoriasis can be serious.
Some people with psoriasis also develop a type of arthritis, known as psoriatic arthritis (PsA).
Psoriatic arthritis can affect both the skin and the joints.
Most people develop psoriasis first, but sometimes the arthritis develops before the skin lesions appear.
The symptoms of PsA include:
- stiffness, especially first thing in the morning, or after resting
- redness, swelling, and pain around the joints and tendons
- a noticeably swollen finger or toe, known as a "sausage digit"
- pain in the heel, lower back, or in a swollen finger or toe
- reduced range of movement at the affected joint
- symptoms of nail psoriasis
- flaking silver patches of skin and inflammation under the skin, which is usually red
- inflammation of the skin and the symptoms of psoriasis
PsA can affect the eyes:
Iritis, or inflammation of the iris, can occur. The eye becomes red, and there may be sensitivity to light.
Uveitis is an inflammation of the uvea, which includes the iris and other parts of the eye. Symptoms include redness of the eye, blurred vision, unusual sensitivity to light, and eye pain.
Apart from the joints, PsA can sometimes affect the spine. Also known as spondylitis, this involves:
- inflammation of one or more of the vertebrae of the spine
- inflammation where ligaments and tendons attach to the spine
Symptoms may include pain and stiffness in the lower back, upper buttock area, neck, and the rest of the spine.
Symptoms are usually worse on waking up or after long periods of inactivity.
Psoriasis is a condition that probably affects between 2 and 2.6 percent of people in the United States. It is not a contagious disease, but it can be uncomfortable. It can also lead to depression, anxiety, stress, and a reduced quality of life.
As it is a systemic condition, a number of complications can also develop.
However, treatment can relieve symptoms and reduce the chance of a flare.
Anyone who experiences unusual skin, nail, or joint changes should see a doctor, who will be able to prescribe medication and offer advice.