What does psoriasis look like?
Psoriasis pictures can help people tell psoriasis from other skin conditions, plus identify different types of psoriasis.
What is psoriasis?
Psoriasis is a type of autoimmune condition. Similarly to other autoimmune diseases, psoriasis occurs when the immune system attacks healthy tissue instead of invaders like bacteria and viruses.
Psoriasis causes skin cells to accumulate at an abnormal rate, leading to an overgrowth of the skin that produces lesions. The condition is most common on the hands, feet, face, genitals, scalp, and in skin folds, although it can develop anywhere.
Doctors do not fully understand the disease, although it seems to be genetic. Psoriasis outbreaks are often triggered by factors such as:
- an injury to the skin
- certain medications
- skin infection
- environmental triggers
Some people with psoriasis find that dietary changes can reduce the frequency of flare-ups.
Psoriasis is not contagious but it is a chronic illness and incurable. Medication and some other treatments can help control outbreaks, reducing the frequency and severity of symptoms.
Types of psoriasis
Plaque psoriasis is the most common type of psoriasis. People with plaque psoriasis develop raised, red, scaly patches of skin. The rash usually has well-defined edges, making it distinct from similar-looking skin conditions, such as eczema.
The rashes associated with this type of psoriasis tend to be thick and dry-looking, with pits spread throughout. 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 scales are painful and itchy, and may crack open and bleed. Plaque psoriasis can become infected, particularly if left untreated, due to frequent scratching and broken skin.
Guttate psoriasis is the second most common form of psoriasis and often begins in childhood or early adulthood. Guttate psoriasis lesions are small, red, and many in number.
This form of the condition often appears suddenly and has several triggers, including tonsillitis, stress, upper respiratory infections, and skin injuries.
Streptococcus infections, especially strep throat, are among the most common triggers for guttate psoriasis.
People with guttate psoriasis often have other forms of psoriasis, 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 groin. These lesions, unlike other forms of psoriasis, are not scaly typically. This is because the moist environment of skin folds reduces dryness.
Inverse psoriasis is common in overweight people and in those with deep skin folds. The skin-to-skin rubbing that occurs in these areas irritates the skin, and can trigger an inverse psoriasis attack. Regions affected by inverse psoriasis may also develop other infections, including yeast.
Because the skin is thin and sensitive, treatment can be difficult. The skin rapidly absorbs steroid creams, the overuse of which can cause stretch marks, skin irritation, and other symptoms.
The subtypes of pustular psoriasis each follow a predictable pattern:
- Von Zumbusch appears suddenly as red, painful skin. Pustules appear within a few hours. They dry within a day or two, leaving shiny, smooth skin in their wake. Von Zumbusch can cause dehydration and fevers. In children, it may be life-threatening, demanding swift medical care.
- Acropustulosis causes lesions on the fingertips and sometimes on the tips of the toes. The lesions are often triggered by a skin infection or injury, and are frequently painful. Left untreated, they can damage or deform the nails. Severe forms may even damage the bones.
- Palmoplantar pustulosis causes blisters on the soles of the feet and palms of the hands, as well as the sides of the heels and bottoms of the thumbs. Pustules tend to come and go in a cyclical fashion. They begin as red plaques, then turn brown, peel, and become crusty.
Nail psoriasis can occur with any type of psoriasis, but is most common in people with plaque psoriasis. People with nail psoriasis often have scaly plaque psoriasis growths on their fingers or hands.
The nails may become thick and discolored. Loss of nail cells can cause pitting.
Other visual signs of nail psoriasis include:
- nail separating from the nail bed 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 nail
Erythrodermic psoriasis causes widespread redness throughout the body. Pustules are red, crusty, and inflamed, and sometimes occurs alongside Von Zumbusch pustular psoriasis. The borders of the lesions are not well defined, and can be intensely painful.
Rather than flaking off in scales, as in plaque psoriasis, the plaques of erythrodermic psoriasis tend to come off in sheets.
This form of psoriasis can alter body chemistry, causing dehydration and protein loss. Symptoms may include:
- increasing heart rate
- sudden changes in body temperature
Erythrodermic psoriasis can become life-threatening, so necessitates prompt treatment.
Other symptoms of psoriasis
Skin lesions are only the outside manifestation of psoriasis. Because psoriasis occurs when the body attacks healthy cells, people with psoriasis may experience other symptoms. These include infection of psoriasis lesions.
About 30 percent of people with psoriasis develop psoriatic arthritis. Psoriatic arthritis causes inflammation in the joints. Joints may be painful, weak, and swollen. Psoriatic arthritis can also cause fatigue. Left untreated, this form of arthritis can cause permanent joint damage.
Proper treatment for psoriasis depends on the severity of the symptoms. Doctors generally start with treatments that are well tolerated by a person, adjusting the treatment regimen based on how well symptoms respond.
Topical creams are applied directly to the skin and can reduce the symptoms of psoriasis.
Treatments can include:
- Phototherapy: Regular exposure to ultraviolet (UV) light.
- Systemic drugs: These drugs may be taken orally or via injection, and include drugs such as methotrexate and cyclosporine.
- Biologics: These protein-based drugs are given via intravenous (IV) infusion.
- New oral treatments: A number of new oral treatments feature "small molecules" that target immune cells and are effectively absorbed by mouth.
- Lifestyle changes: Avoiding known triggers, and promptly treating triggers such as strep throat, can reduce the frequency and severity of outbreaks.
- Topicals: Topical remedies such as corticosteroids often reduce symptoms, and some are available over the counter.
- Complementary and alternative remedies: Some people with psoriasis find that alternative remedies, including special diets, acupuncture, and homeopathy, reduce symptoms.
When to see a doctor
Psoriasis is highly treatable, but a proper diagnosis is necessary for treatment.
People should see a doctor for psoriasis if:
- the rash is accompanied by other symptoms, especially fever, weakness, chills, or intense pain
- the lesions appear to be infected, and have pus oozing from them
- red lines are coming out of the lesions, as this can indicate a rapidly spreading infection
- signs of erythrodermic psoriasis are present
- a child shows signs of Von Zumbusch psoriasis
- psoriasis treatment is not working, or is causing serious side effects
- it is the first outbreak a person has experienced
People should also consult a doctor if their psoriasis does not follow its usual pattern. For example, a person whose psoriasis outbreak usually lasts for a week should see a doctor if the lesions last for longer than 2 weeks.