Psoriasis and lupus: What's the difference?
In this article, we take a close look at the similarities and differences between psoriasis and lupus, including the symptoms, causes, and treatments. We also cover what happens when people have both conditions.
What is psoriasis?
Psoriasis causes patches of red, scaly skin.
Psoriasis is a chronic autoimmune disease that affects a person's skin.
Psoriasis causes the skin cells to reproduce at an abnormally fast rate. This leads to a build-up of skin cells on some parts of the body, and red, scaly patches can appear.
The areas of the body that psoriasis most commonly affects include:
People with psoriasis typically experience periodic flares throughout their lifetime. However, each of these flares will subside, and symptoms can remain minimal for extended periods between them.
What is lupus?
Lupus, or systemic lupus erythematosus, is an autoimmune disease that causes the immune system to attack the body's tissues, resulting in damage.
This damage can affect almost any of the body's systems, including:
This chronic condition has no cure, but treatment can help people manage the symptoms.
Similarities and differences between psoriasis and lupus
Lupus and psoriasis share some similarities but also have several key differences.
Lupus is much less common than psoriasis.
According to the Lupus Foundation of America, there are approximately 1.5 million cases of lupus in the United States. In comparison, the National Psoriasis Foundation estimate that psoriasis affects about 7.5 million Americans, 10 to 30 percent of whom will develop psoriatic arthritis.
Who is affected?
Psoriasis can affect people of any age. People often develop this condition between 15 and 35 years of age.
Both psoriasis and lupus are types of autoimmune disease, which means that the immune system mistakenly attacks healthy cells.
However, while lupus may cause the immune system to attack multiple parts of the body, including the skin, joints, and organs, psoriasis is typically limited to the skin, fingernails, and toenails. People with psoriatic arthritis can also have symptoms in their joints.
Doctors do not know what causes either psoriasis or lupus. Researchers believe that there is a genetic component to developing both conditions. They also think that specific lifestyle and environmental triggers could cause either condition to flare.
Are they contagious?
Neither lupus nor psoriasis is contagious. It is not possible to contract one of these conditions or pass it onto another person.
Links with cancer
Psoriasis and lupus do not cause cancer. However, some research indicates that psoriasis may increase a person's risk of developing cancer. For example, a 2016 review described psoriasis as a risk factor for certain types of cancer.
Psoriasis and lupus have no known cures, but doctors can treat both conditions using a variety of therapies and medications. Both tend to have mild-to-moderate symptoms, but lupus has the potential to be life-threatening.
Symptoms of psoriasis and lupus
Lupus can cause rashes after sun exposure.
The symptoms of psoriasis and lupus may take effect throughout the body, but they can be particularly apparent on the skin or in the joints. While psoriasis and psoriatic arthritis can be uncomfortable, they are generally less serious than lupus and may cause less severe symptoms.
Psoriasis symptoms will vary from person to person and according to the type of psoriasis.
Typical symptoms may include:
- red patches of skin that flake or develop scales
- the appearance of thick, white patches of skin called plaques on the elbows, knees, and other areas of the body
- patches of skin that itch, crack, or bleed
- shiny, red lesions in folds of skin
- small red dots on the trunk, in the case of guttate psoriasis
- in cases of psoriatic arthritis, pain and distortion in the joints, particularly in the fingers, toes, and knees
Psoriasis symptoms will be worse when a person is experiencing a flare. At other times, they may be very mild or even seem to disappear for some time.
People with lupus also tend to experience flares interspersed with periods of milder symptoms. The symptoms will vary between people and may even differ from one flare to another in the same person.
Lupus symptoms can include the following:
- confusion and memory problems
- a butterfly-shaped rash on the face
- joint pain
- body rashes, particularly after sun exposure
- fingers or toes turning blue or white on exposure to the cold
- chest pain
- shortness of breath
Treatment for psoriasis and lupus
Both psoriasis and lupus require medical care. Doctors can recommend the best treatment for each case of psoriasis or lupus.
For psoriasis, doctors may recommend the following treatments:
- avoiding and managing stress
- topical corticosteroids
- salicylic acid
- topical vitamin D
- UVB light therapy
- keeping the skin clean and moisturizing it well
- taking care to prevent cuts and sunburn
If a person has psoriatic arthritis, doctors may recommend anti-inflammatory and antirheumatic medications to help manage the condition.
For lupus, doctors may recommend the following treatments:
- anti-inflammatory medications for joint pain
- corticosteroids to reduce inflammation
- immunosuppressant medicines and chemotherapy to prevent the immune system from damaging the organs
- antirheumatic drugs
- BLyS-specific inhibitors
Additionally, a doctor may suggest that people with lupus take special care to avoid stress, get adequate rest, and follow a healthful diet. Doctors may also recommend avoiding exposure to sunlight where possible.
Diagnosing psoriasis and lupus
A doctor will assess a patient's medical history to diagnose psoriasis or lupus.
People should schedule an appointment with a doctor if they experience any of the symptoms of psoriasis or lupus.
To diagnose either of these conditions, doctors will ask the individual about their symptoms, including whether or not they have flares and any known triggers. If possible, it can be beneficial to give the doctor a list of dates and symptoms to help establish a history of flare-ups.
When doctors suspect lupus, they may advise seeing a rheumatologist. This specialist may recommend additional team members to help a person manage their symptoms.
In cases of psoriasis, a person is likely to see a primary care physician or dermatologist. A person will generally only see a rheumatologist for psoriasis if their joints are stiff or swollen or they have psoriatic arthritis.
What happens when you have both psoriasis and lupus?
Rarely, a person can have both lupus and psoriasis. When this occurs, the individual is likely to receive treatment from the same medical team.
Treatment will focus on managing the symptoms of both diseases, and there may be additional triggers that people need to avoid.
Psoriasis and lupus are both autoimmune conditions that can cause skin problems. Although there are some similarities between them, these conditions have different causes and symptoms. Lupus is more severe than psoriasis.
It is rare to have both lupus and psoriasis, but it is possible.
People can manage both conditions using medications and home treatments. Some people may also benefit from counseling if their condition affects their mental health. People may be able to minimize flares by avoiding known triggers.