This article gives an overview of the current theories about this link. Also, we look at how to treat psoriasis and the infection known as candidiasis, the effect of diet on these illnesses, and different treatment options.
What are psoriasis and Candida?
Candida is a type of yeast that causes a fungal infection on the body.
Psoriasis is an autoimmune disease that causes red, itchy, scaly patches of skin. Psoriasis happens due to an overactive immune system that attacks healthy skin cells. This overreaction speeds up the production of new skin cells, causing the symptoms of psoriasis.
Candida is a type of yeast that can cause a fungal infection called candidiasis. When this develops in the mouth, it is called thrush. Candidiasis in the vagina is called a yeast infection.
Everyone have some Candida yeast in and on their body. It is only when too much of it develops that it results in candidiasis.
Does one cause the other?
There is a clear link between psoriasis and candidiasis, but more research needs to be done to explain this link fully.
A 2018 meta-analysis found that people with psoriasis had more Candida in their bodies than those without psoriasis.
The researchers point out that a person's autoimmune response to skin issues uses similar mechanisms to when it responds to candidiasis. It may be that when the body fights a Candida infection, this also triggers the autoimmune response that causes a person's psoriasis.
However, it is also likely that some medications for psoriasis make people more susceptible to fungal infections, including candidiasis, since they inhibit the immune system.
A study in the American Journal of Clinical Dermatology found a similar relationship. The researchers note that Candida can make psoriasis worse, and certain medications for psoriasis may make a person more likely to develop candidiasis.
However, despite this, the study found that a person taking psoriasis medication is still at relatively low risk of developing candidiasis. When it does develop then antifungal medication is usually effective.
The authors conclude that a person taking psoriasis medication should not need to change their treatment because of the risk of candidiasis.
More research needs to be done to determine how the connection between psoriasis and Candida works.
Links with diet
Eating a healthful diet may help treat psoriasis and Candida.
The relationship between a person's diet and psoriasis or candidiasis is not clear. There is no evidence that points to a particular diet that might reliably improve either of these illnesses.
However, research has shown that eating a nutritious diet and maintaining a healthy weight improve many health conditions.
If a person thinks that a particular food or drink makes their psoriasis or candidiasis worse, they can keep a food diary and try cutting out one food at a time to see if it makes a difference.
As always, discussing these choices with a doctor is the best way of making an informed choice.
According to the Centres for Disease Control and Prevention (CDC), psoriasis symptoms include red, itchy skin, sometimes with silvery scales. Psoriasis can develop nearly anywhere on the body.
Candidiasis can occur in three areas:
- in the mouth, as thrush
- in the vagina, as a yeast infection
- within the body via the bloodstream, as invasive candidiasis
According to the CDC, the symptoms of thrush can include:
- white patches in the mouth
- soreness in the mouth
- a "cottony" feeling in the mouth
- loss of taste
- cracked skin at the corners of the mouth
Vaginal yeast infection
The symptoms of a vaginal yeast infection include:
- itching or soreness around the vagina
- pain during sex
- pain when urinating
- white vaginal discharge that is thick and clumpy
The symptoms of invasive candidiasis can be difficult to tell apart from other illnesses. They may include a fever and chills.
Other symptoms can also occur if it spreads to specific parts of the body.
Prescription lotions can help people treat psoriasis.
In the case of psoriasis, a doctor may prescribe lotions for a person to apply directly to the affected skin. They may also recommend oral medications or light therapy. The severity and location of a person's psoriasis will affect the type of treatment a doctor suggests.
Treatment for a candidiasis infection is an antifungal medicine that people can apply directly to the infected area. If these do not work, or if the candidiasis keeps returning, other medication may be necessary.
While some psoriasis treatments may increase the risk of Candida overgrowth, there is little evidence to suggest a person should change their medication because of this concern.
A person can help manage their psoriasis by:
- avoiding skin injuries, such as cuts and grazes
- avoiding sunburn
- avoiding scratching areas of psoriasis
- avoiding flare-up triggers, such as stress, cold weather, or bug bites
According to the CDC, a person can help prevent candidiasis in the mouth by maintaining good oral hygiene and help avoid a vaginal yeast infection by wearing cotton underwear and only taking antibiotics when essential.
While there is a clear link between psoriasis and Candida infections, researchers are not sure how these conditions affect each other.
A person with psoriasis should look for signs of candidiasis, but not enough evidence suggests they should make any further changes to their lifestyle or medications.