What does psoriasis look like?
Recognizing psoriasis and getting an early diagnosis can help a person access effective treatment, manage symptoms, and possibly reduce the frequency and severity of flares.
What is psoriasis?
Psoriasis results from a problem with the immune system. It leads to an overgrowth of skin cells, among other physical changes.
As the skin cells grow too fast, they accumulate on the surface, forming lesions or plaques of thickened, scaly skin that can be painful or itchy.
Depending on the type of psoriasis, skin changes often affect the:
- other areas where the skin folds
However, psoriasis can affect any area of the skin. These symptoms tend to come and go. When symptoms get worse for a period, doctors refer to this as a flare.
What does psoriasis look like on black skin? Find out here.
Types of psoriasis
The rash usually has well-defined edges, unlike eczema, which can resemble plaque psoriasis in other ways.
It can also become thick and dry, with pits throughout, and the lesions are often flaky.
Plaque psoriasis is common on the scalp, elbows and knees, face, lower back, soles of the feet, and palms of the hands.
The plaques can be painful and itchy, and they may crack and bleed. If the skin breaks, an infection can develop.
Streptococcus infections, especially strep throat, are among the most common triggers for guttate psoriasis.
People with guttate psoriasis often have other forms as well, such as plaque psoriasis.
Inverse psoriasis lesions are flat, red, and shiny. They are large and uniform and typically appear in skin folds, such as in the armpit, under the breasts, or in the groin.
These lesions are not usually scaly because the moist environment of skin folds reduces dryness. Inverse psoriasis is common in people with excess weight and in those with deep skin folds.
As skin rubs on skin, it can lead to irritation, triggering symptoms. Infections, such as yeast infections, can also develop.
Pustular psoriasis produces numerous tiny white blisters on red skin.
There are several subtypes:
- Von Zumbusch appears suddenly as red, painful skin. Pustules tend to develop within a few hours. They usually dry up within a day or two, leaving shiny, smooth skin. Von Zumbusch pustular psoriasis can cause dehydration and fevers. It may be life-threatening, especially in children, and requires swift medical care.
- Acropustulosis causes lesions on the fingertips and sometimes on the tips of the toes. A skin infection or injury may trigger it, and the lesions are frequently painful. Without treatment, they can damage or deform the nails, and a severe case can damage the bones.
- Palmoplantar pustulosis causes blisters to form on the soles of the feet, the palms of the hands, the sides of the heels, and the bottoms of the thumbs. Pustules tend to come and go cyclically. They begin as red plaques, then turn brown, peel, and become crusty.
Image credit: DermNet.
Nail psoriasis can occur with any type of psoriasis, but it is most common with plaque psoriasis. Skin plaques may form on the fingers or hands.
The nails may become thick, discolored, and pitted.
Other signs include:
- the nails separating from the nail beds and turning yellow
- yellowish red discoloration in the nail, which may be sore to the touch
- ridges and lines in the nails
- psoriasis scales under the nails
Image credit: James Heilman MD 2010
This causes widespread redness throughout the body. Pustules are red, crusty, and inflamed. The borders of the lesions are not well defined and can be intensely painful. It may occur alongside Von Zumbusch pustular psoriasis.
While in people with plaque psoriasis, the affected skin flakes off in scales, the plaques of erythrodermic psoriasis tend to come off in sheets.
This form of psoriasis can reduce the skin's effectiveness as a protective barrier. It can lead to dehydration, changes in chemical balance, and protein loss.
Symptoms can include:
- an increased heart rate
- sudden changes in body temperature
Erythrodermic psoriasis can become life-threatening and needs prompt treatment. A person may need to spend time in the hospital.
Other symptoms of psoriasis
Psoriasis does not only affect the skin. It is a multisystem condition that can have other effects.
About 30 percent of people with psoriasis develop psoriatic arthritis, which involves inflammation, pain, and swelling in the joints. Psoriatic arthritis can also cause fatigue. Without treatment, it can lead to permanent joint damage.
A person with psoriasis is more likely to experience other inflammatory conditions, including cardiovascular disease, diabetes, and obesity. Current guidelines recommend regular screening for these issues.
Causes and triggers
The exact cause of the condition is unclear, but it appears to involve both genetic and environmental factors. Even if a person inherits these genetic factors, they may never develop psoriasis, unless they encounter a trigger.
Triggers may include certain infectious diseases, such as strep throat. The issues below can both trigger the initial appearance of psoriasis and cause existing symptoms to flare:
- injury to the skin
- the use of certain medications
- skin infection
- alcohol consumption
- cold weather
Psoriasis is not contagious — one person cannot pass it one to another.
A range of treatments can help manage symptoms and reduce the risk of flares.
Topical creams can help manage mild symptoms.
The best course of treatment depends on the type of psoriasis and the severity of symptoms. Topical treatments are often enough to manage mild symptoms.
For moderate to severe symptoms, current guidelines recommend a relatively new type of drug, called a biologic.
Biologics target specific components of the immune system and can help reduce the frequency of flares and the severity of psoriasis symptoms. They are for long-term use. These drugs are proving to be effective, but they may not suit everyone, as they can increase the risk of infections.
Other treatments — such as steroids — are for short-term use. They can treat symptoms as they arise.
A doctor will discuss the treatment options and help determine the best choices.
The range of psoriasis treatments includes:
- Topicals: These include ointments, creams, moisturizers, and emollients that can contain corticosteroids and other effective ingredients. Some are available over the counter.
- Moisturizers and emollients: Ask a pharmacist about options. Thicker products that are hypoallergenic and fragrance-free are usually best.
- Phototherapy: Regular exposure to ultraviolet (UV) light or controlled sun exposure may help. Laser therapy is another option.
- Systemic drugs: A person can take these orally or via injection. They include steroids, methotrexate, cyclosporine, and retinoids, such as acitretin.
- Biologics: A doctor may prescribe these, depending on the type of psoriasis and the severity of symptoms.
- Lifestyle changes: Avoiding known triggers and promptly treating triggers such as strep throat can reduce the frequency and severity of outbreaks.
- Complementary and alternative remedies: A 2018 review found that Indigo naturalis, curcumin, fish oil, dietary changes, meditation, and acupuncture may reduce symptoms.
New discoveries are leading to new treatment options. Anyone who already has a treatment plan may wish to speak to their doctor about the latest options.
Ask a pharmacist for advice when choosing an over-the-counter topical treatment for psoriasis. Thicker products that are hypoallergenic and fragrance-free are usually best.
How can a gluten-free diet help some people with psoriasis? Click here to find out more.
When to see a doctor
Getting a psoriasis diagnosis is the first step toward effective treatment. It is also important to seek medical attention when symptoms change.
See a doctor if:
- There are new symptoms or existing symptoms worsen.
- Seemingly unrelated symptoms occur, especially a fever, weakness, chills, or intense pain.
- There are signs of infection, such as oozing pus.
- Red lines spread from the lesions, as this can indicate a rapidly spreading infection.
- There are signs of erythrodermic or guttate psoriasis.
- Skin changes are widespread.
- Psoriasis treatment is not working or is causing serious side effects.
Also, consult a doctor about any changes in the pattern of psoriasis symptoms. For example, if a flare usually lasts 1 week, see a doctor if symptoms persist beyond 2 weeks.