Psoriasis is an umbrella term for several skin conditions which share certain similarities but present in distinct ways. Psoriasis is a chronic condition, meaning that it persists indefinitely throughout a patient’s life. There is not presently a cure for the condition, but treatments are available to help ease some of the symptoms. While generally not harmful or fatal, psoriasis can be quite uncomfortable or even painful, and can lead patients to become self-conscious of the appearance of their symptomatic skin.

The most common presentation of psoriasis is in discrete, scaly patches of thickened or inflamed skin. This form of psoriasis is known appropriately as “Plaque Psoriasis”, and because it is the most common form, will be the primary subject of this article.


Though psoriasis is caused by an underlying immunological condition, its primary and defining symptom is the formation of rash-like lesions on the skin. These areas can present in a number of ways, but one of the most common manifestations is for the rashes to appear in circular blotches, where the skin inside the circular area is thickened, red or pink, inflamed, itchy, sore, and has a “scaly” appearance.

Virtually no external part of the body is off-limits when it comes to predicting where psoriasis plaques may appear. Anywhere that is covered with skin can become the site of a psoriasis rash. However, commonly affected areas include the joints of the extremities (i.e., elbows and knees), the face, scalp, trunk, palms, and genitals.

While psoriatic plaques can be unpleasant, one saving grace is that they tend not to be constantly present. Instead, they tend to appear and disappear in “flare ups”, leaving patients with periods where their skin is asymptomatic and healed between outbreaks.

Most people who suffer from psoriasis experiencer the plaque variety, with estimates suggesting that the proportion may be as high as 80 – 90%. Still, other forms are possible, including pustular psoriasis (where pus-filled bumps arise on affected areas), nail psoriasis (where the fingernails and toenails become discolored and pitted), and erythrodermic psoriasis (a severe form of psoriasis affecting the majority of the skin’s surface area).

Plaque Psoriasis

Causes and Risk Factors

No particular demographic seems to be more vulnerable to psoriasis than others. However, there may be a genetic component to psoriasis, which may mean that the children of psoriasis patients are more likely to also experience psoriasis.

Psoriasis is not pathogenic or contagious, meaning that there are no bacteria or viruses involved in the development of this disease. Instead, psoriasis is an autoimmune disorder. Similar to diseases like type 1 diabetes or rheumatoid arthritis, the immune systems of psoriasis patients mistakenly view their bodies’ own cells as foreign pathogens invading the body, and thus respond by attacking the cells. In psoriasis, this reaction is specifically targeted at the skin cells, which is why the resulting inflammation and damage appears on the surface of the skin. Because of this immune barrage, skin cells respond by accelerating the speed at which they replicate. This causes the thickening of skin into plaques.

Oddly, psoriasis and arthritis seem to share some sort of connection. Roughly 30% of psoriasis patients will also receive a diagnosis of arthritis in their lifetime. While a skin condition and a joint condition might seem totally unrelated, their co-morbidity is likely due to the auto-immunological nature of the causes of these conditions.

Though psoriasis is always present in its patients, flare-ups may result from environmental triggers to which a patient is exposed. Triggers can vary from patient to patient, but may include stressful times, injuries or infections, other medications, or weather changes.


If you suspect you may have psoriasis, the best course of action is to seek a medical opinion to either confirm your suspicion or propose an alternate diagnosis. Though psoriasis is not particularly harmful or life-threatening, its effects can be distressing to patients, so seeking effective diagnosis and treatment is advisable.

Your primary care provider may diagnose your condition, or they may refer you to a dermatologist (a doctor specializing in skin health). In either case, the doctor will likely conduct a visual examination of your skin, coupled with questions about the nature of your symptoms and what has precipitated episodes or outbreaks previously.

Psoriasis symptoms can be unambiguous, but they can also overlap with symptoms of other conditions, making it not always possible to diagnose psoriasis from a visual exam alone. In some cases, a doctor may wish to conduct additional procedures to affirm a diagnosis. This will typically involve a biopsy of the affected skin, where a small skin sample is taken and analyzed in a lab.

Treatment Options

To date, no cure has been discovered for psoriasis, meaning those afflicted with it are limited to controlling the symptoms. Thankfully, numerous options exist, allowing patients to find an optimal solution for their needs and for the severity of their psoriasis. Many doctors will advise their patients to begin with milder options, and progress only to more intensive measures if the desired outcome is not achieved.

While the treatment options operate through a variety of mechanisms, they all have the same general aim: to slow the pace of skin cell turnover and remove or prevent the growth of plaques.

Topical therapy

Topical therapy simply describes treatments involving the application of a product to the skin directly, as with a cream or ointment. An advantage to topical solutions is the ability to target only the affected areas, potentially limiting or localizing some side effects.

Within the category of topical therapies, there are numerous sub-categories according to their mechanisms of action. While the details of their function are beyond the scope of this article, some common categories include corticosteroids, vitamin D analogues, calcineurin inhibitors, and coal tar formulations. Each product class has its own unique attributes that may make it more or less suitable for any given individual. Speak to your doctor for more information about topical therapies, and be sure to always follow the usage directions included with the product or otherwise as directed by your doctor and/or pharmacist.

Woman receiving light therapyLight therapy

This non-invasive treatment approach involves exposing affected skin to specific sources of light regularly. The trick is that not just any light will do – specific wavelength ranges of ultraviolet light are administered to affected skin in short bursts by a professional in order to minimize side effects and maximize the beneficial effects of this treatment.

When administered properly, light therapy can slow the reproduction of skin cells, lessening the thickening effect that contributes to the formation of plaques. It can also reduce inflammation and the uncomfortable sensations which often accompany psoriasis outbreaks.

While this can be an effective and relatively safe method to try, it is not for everyone. Some people may be at higher risk of complications or ineffective treatment due to the nature of their psoriasis case, their skin type, or other medical history. Pregnant women may also be advised to avoid certain forms of phototherapy due to a greater risk of certain complications.

If you think phototherapy may be a useful intervention for your psoriasis, consult with your doctor to obtain their opinion. To be clear, phototherapy must only be performed by a professional, and attempts to “DIY” phototherapy through sun exposure or exposure to other sources of UV light are strongly discouraged due to their associated risk and inefficacy.


Ever since the autoimmunological nature of psoriasis was discovered in the 1960s, pharmaceutical companies have exploited that knowledge to offer psoriasis treatments of varying efficacies. Several categories of drugs exist that seek to alter some aspect of the body’s immune system such that the harmful interaction between psoriatic patients’ immune systems and skin cells could be lessened or extinguished altogether. Major examples include corticosteroids, methotrexate, and cyclosporine – drugs which have been a staple of psoriasis treatment for decades.

Tremfya (Guselkumab)More recent advancements in other areas of medicine have led to the advent of biologics – a new class of drugs with a novel approach to regulating the immune system. While these drugs were mainly developed in the contexts of other immunological conditions, psoriasis’ relation to the immune system’s action meant these drugs had exciting potential for psoriasis as well.

One recent example of such biologic medications is Tremfya (guselkumab). FDA-approved in 2017 for the treatment of psoriasis and in 2020 for psoriatic arthritis, Tremfya is the first drug that works by specifically blocking a single immune agent known as interleukin-23. By narrowly inhibiting this one agent, Tremfya impedes the release of inflammatory chemicals known as cytokines, which are thought to play a significant role in the inflammation characteristic to psoriatic plaques, while limiting the degree to which the patient’s immune system suffers as a whole.

Clinical studies have revealed that Tremfya performs significantly better than placebo and some other medications in terms of alleviating symptomatic psoriasis over a 16-week period. However, like every drug, side effects have also been reported with this medication, including respiratory infections, GI tract distress, and headaches. Still, Tremfya appears to be tolerated relatively well amongst the general population.

If you are interested in trying Tremfya, or any other psoriasis treatment, be sure to speak to your doctor. Remember that no two patients are likely to respond identically to any medication, so always communicate any side effects or other concerns to your doctor as soon as possible.


Psoriasis can be an unpleasant condition but is ultimately mostly benign. While it cannot be cured outright, effective treatments are available that can make a significant difference in the prognosis of the condition.

Recent advances in pharmacology have brought about new medications like Tremfya which may provide improved efficacy and fewer side effects over other options. And, patients can feel optimistic about other medications that are likely to improve the quality of care even further in the future.

If you think you might be suffering from psoriasis, or if you resisting treatment is less effective than you would have hoped for, consider speaking to your doctor about exploring other options.