Knowing which kind of psoriasis you have helps you and your doctor make a treatment plan. Most people have only one type at a time. Sometimes, after your symptoms go away, a new form of psoriasis may crop up in response to a trigger.
In general, most types of psoriasis result from the same triggers:
- Skin injury
Other things that may trigger psoriasis include:
Here's how you can spot the seven types of psoriasis and what you can do to treat them.
This is the most common type. About eight in 10 people with psoriasis have this kind. You may hear your doctor call it "psoriasis vulgaris."
Plaque Psoriasis Symptoms:
Plaque psoriasis causes raised, inflamed, red skin covered with silvery, white scales. On darker skin, the patches may be purplish with gray scales. These patches may itch and burn. It can appear anywhere on your body, but it often pops up in these areas:
- Lower back
Plaque Psoriasis Treatments:
- Topical treatments: These go on your skin and are usually the first thing doctors try. Some have steroids; others don’t. Prescription products slow skin cell growth and ease inflammation.
- Phototherapy: This treatment uses ultraviolet light. You’ll get it at your doctor's office or at home with a phototherapy unit.
- Systemic medications: These prescription drugs work throughout your body. You’ll get them if you have moderate to severe psoriasis that doesn’t respond to other treatments. You could take them by mouth or get them as a shot or IV. This category includes drugs called biologics, which target specific parts of your immune system that play a role in the inflammatory process. Learn more about systemic treatments for psoriasis.
This type often starts in children or young adults. It makes up about 8% of psoriasis cases.
Guttate psoriasis causes small, pink-red spots on your skin. On darker skin, the spots may be purplish. They often appear on your:
- Upper arms
This type of psoriasis may go away within a few weeks, even without treatment. Some cases, though, are more stubborn and require treatment.
This type is usually found in these locations:
- Under the breasts
- Skin folds around the genitals and buttocks
- Patches of skin that are bright red, smooth, and shiny, but don't have scales
- Getting worse with sweating and rubbing
Common triggers are:
- Fungal infections
This kind of psoriasis is uncommon and mostly appears in adults. It causes pus-filled bumps (pustules) surrounded by red or purplish skin. These may look infectious but are not.
This type may show up on one area of your body, such as the hands and feet. Sometimes, it covers most of your body, which is called "generalized" pustular psoriasis. When this happens, it can be very serious, so get medical attention right away.
- Topical medicine (ointments you put on your skin) or systemic medicine (drugs that treat your whole body), especially steroids
- Suddenly stopping systemic drugs or strong topical steroids that you used over a large area of your body
- Getting too much ultraviolet light without using sunscreen
- Exposure to certain chemicals
This type is the least common, but it's very serious. It affects most of your body and causes widespread, fiery skin that appears to be burned.
Other symptoms include:
- Severe itching, burning, or peeling
- A faster heart rate
- Changes in body temperature
If you have these symptoms, see your doctor right away. You may need to get treated in a hospital. This type of psoriasis can cause severe illness from protein and fluid loss. You may also get an infection, pneumonia, or congestive heart failure.
- Suddenly stopping your systemic psoriasis treatment
- An allergic drug reaction
- Severe sunburn
- Medications such as lithium, antimalarial drugs, cortisone, or strong coal tar products
Erythrodermic psoriasis may also happen if your psoriasis is hard to control.
Up to half of those with psoriasis have nail changes. Nail psoriasis is even more common in people who have psoriatic arthritis, which affects your joints.
- Pitting of nails
- Tender, painful nails
- Separation of the nail from the bed
- Color changes (yellow-brown)
- Chalklike material under your nails
You're also more likely to also have a fungal infection.
Psoriatic arthritis is a condition where you have both psoriasis and arthritis (joint inflammation). In more than 80% of cases, people had psoriasis for an average of 12 years before getting psoriatic arthritis. About 90% of people with it also have nail changes.
- Painful, stiff joints that are worse in the morning and after rest
- Sausage-like swelling of the fingers and toes
- Warm joints that may be discolored
Psoriasis vs. Parapsoriasis
Parapsoriasis is the term for a group of rare skin problems that look like psoriasis but behave differently. Your doctor may need to take a sample of your skin (biopsy) to be sure of what you have.
Like psoriasis, parapsoriasis shows up as a patchy rash. Spots are usually pink or red but also can appear brown or yellowish. They can be raised and bumpy with a scaly or wrinkly appearance.
You typically get them on your chest, stomach, and back, but they also may appear on your arms and legs. They're generally round or oval but can be different sizes.
You may have itching, but you probably won't have any other symptoms.
Types of Parapsoriasis
There are two kinds:
- Small-plaque: Rash spots are less than 5 cm across. It's usually considered harmless.
- Large-plaque: Rashes are bigger and sometimes irregularly shaped. Some people with this form develop a kind of lymphoma called mycosis fungoides. It's a cancer of the white blood cells that starts in the skin. Some doctors consider large-plaque parapsoriasis a separate disease. Others think it's just an early stage of mycosis fungoides.