Psoriasis Overview


Psoriasis is a common chronic inflammatory skin disease, and its causes are complex and diverse, involving genetics, environmental and immune system factors. Globally, it is estimated that approximately 2-4% of the population is affected by this condition.1 It occurs more often in adults around 30 and 60 years of age and affects women and men equally.1

What is psoriasis?

Psoriasis is a non-contagious common chronic inflammatory skin disease that usually affects the scalp, back, elbows and knees, but it can affect any body part. Its peak occurrence is between 20-30 years of age, followed by another peak between 50-60 years. The prevalence of the disease has been increasing in the last decades.1

The severity of the symptoms of psoriasis differs between individuals. In general, the symptoms come in cycles, with periods of mild symptoms or no symptoms at all, followed by severe symptoms that can take a few weeks or months to disappear.1,2


Psoriasis is classified into different types depending on the form of the lesions and the body part that it affects. People are more often affected by only one type, but two types can also appear simultaneously in an individual.1,2 The most common types of the disease are:

  • Psoriasis Vulgaris: causes dry patches of skin that become scales that can be itchy or sore. It most commonly affects the scalp, back, elbows and knees.
  • Nail psoriasis causes small dents, irregular growth, and discolouration of the nails.
  • Scalp psoriasis: characterized by dry patches of skin that become scales in parts or in the whole scalp.
  • Guttate psoriasis: causes small patches of skin which become scales on the chest, legs, scalp, and arms.
  • Inverse psoriasis: causes dry patches of skin that become scales on the folding areas of skin, such as under the breasts and armpits.


Psoriasis happens due to a replication of skin cells at a faster rate than normal, with new cells being produced in around one week instead of the regular four weeks. The excess of new skin cells “build up”, forming the patches and scales, is a main characteristic of the disease. The causes of psoriasis are diverse and complex, involving genetics, environmental and immune system factors.3  

The exact role of genetics on psoriasis is unclear, but it is known that having a close relative that has the condition increases the risk of developing psoriasis. Studies have shown that many different genes might be involved in this mechanism. Additionally, in individuals with psoriasis, the immune system is deregulated and acts against healthy skin cells.3

Risk factors

The main environmental risk factors related to psoriasis are:1,2,3

  • Injury to the skin (e.g. surgical incisions, cuts, bites, tattoos);
  • Drinking alcohol (the greater the amount, the higher the risk);
  • Smoking (the greater the amount, the higher the risk);
  • Stress (emotional and/or physical);
  • Medication use (e.g. lithium; non-steroidal anti-inflammatories such as ibuprofen; angiotensin-converting enzyme inhibitors such as captopril and enalapril; beta-blockers such as atenolol and carvedilol);
  • Streptococcal throat infections (especially for children and adolescents).

You can reduce your risk of psoriasis by making a few changes to your lifestyle

The following lifestyle factors have the greatest impact on your risk of psoriasis. We will also look at what you can do to reduce your risk from today.


Maintaining a healthy diet may help reduce the risk of psoriasis. Specifically, supplementation of vitamin D, folic acid, and antioxidants might reduce the risk of psoriasis. In general, maintaining a healthy diet, that is, eating a combination of various groups of nutritious food, might protect against the disease.4

Physical activity

Being physically active may reduce the risk of developing psoriasis. However, some types of psoriasis can get worse with sweat, especially inverse psoriasis (the one that appears in folding areas of the skin). This does not mean that individuals with psoriasis should avoid exercising because of the sweat since being physically active is beneficial in many ways. To prevent the sweat from worsening psoriasis, it is indicated to clean up the sweat as soon as possible and not let it stay on the skin too long.4


Obesity not only increases the risk of developing psoriasis but also aggravates already existing psoriasis. Therefore, by preventing obesity, you can reduce the risk of developing and the severity of psoriasis.5


Alcohol use, especially when excessive, increases the risk of developing psoriasis and its severity. Therefore, to diminish the risk of the disease and its severity, it is indicated to avoid or reduce alcohol consumption.6


People with psoriasis suffer from obstructive sleep apnoea and restless legs syndrome more often than those who do not have psoriasis. Psoriasis might also increase the risk of insomnia, which might be related to the itchiness and soreness caused by skin lesions.6

Mental health

Skin diseases such as psoriasis are usually easily visible to others and can be accompanied by stigmatization and prejudice. Together with the impact that the skin lesions can have on one’s physical appearance, the disease, unfortunately, often becomes a burden, which increases the risk of depression, anxiety, emotional stress, and low self-esteem.1,2,3

If you are struggling with these issues, talk to your general practitioner or other healthcare workers about what type of help is best for you. In the United Kingdom, psoriasis associations are very active and can be extremely helpful to those suffering from the disease.


Keeping your emotional health balanced is necessary for your physical health. For individuals who have psoriasis, emotional stress can exacerbate psoriasis. Additionally, the disease itself can increase emotional stress and lead to negative emotions. Therefore, emotional and physical health are intertwined and should be taken into consideration in the management of psoriasis. 

Furthermore, self-care is important for overall good health, especially for people with chronic diseases such as psoriasis. Maintaining a healthy diet, being physically active, and being mindful of your mental health, for example, help to control psoriasis and its possible negative effects on your quality of life.1,2,3


Psoriasis is a common and non-contagious inflammatory skin disease that usually causes dry patches and scales in the skin. Its causes and risk factors are multiple and interconnected, including genetics, the immune system, and environmental factors. Maintaining both physical and mental health decreases the risk of developing psoriasis and its severity. 

Diagnostic testing

At Klarity, we use the latest technology when it comes to diagnostic testing. Our home blood tests give you health insights and personalized recommendations. Find out which test you should take.


  1. Di Meglio P, Villanova F, Nestle FO. Psoriasis. Cold Spring Harb Perspect Med. 2014 Aug 1;4(8):a015354. 
  2. Boehncke WH, Schön MP. Psoriasis. Lancet. 2015 Sep 5;386(9997):983-94.
  3. Kamiya K, Kishimoto M, Sugai J, Komine M, Ohtsuki M. Risk Factors for the Development of Psoriasis. Int J Mol Sci. 2019 Sep 5;20(18):4347. 
  4. Zheng Q, Sun XY, Miao X, Xu R, Ma T, Zhang YN, et al. Association between physical activity and risk of prevalent psoriasis: A MOOSE-compliant meta-analysis. Medicine (Baltimore). 2018 Jul;97(27):e11394.
  5. Jensen P, Skov L. Psoriasis and Obesity. Dermatology 2016;232:633-639. 
  6. Gupta MA, Simpson FC, Gupta AK. Psoriasis and sleep disorders: A systematic review. Sleep Med Rev. 2016 Oct;29:63-75.

Juliana Lima Constantino

Medical Doctor and Master Student in Epidemiology, University of Groningen, Netherlands

Juliana completed her studies in Medicine in Brazil in 2019, during which she studied a year abroad in The Netherlands at Vrije Universiteit Amsterdam and took a Medical Elective in England at Oxford University.

After graduating, she worked as a general practitioner and as an emergency doctor in the frontline against COVID-19 in Brazil. In 2021, she moved to the Netherlands to do her Master in Epidemiology.

She is currently working on her Master Thesis in the Global Health Department, with a focus on maternal and child health. She is passionate about medical writing as it serve as a way of spreading trustworthy knowledge to everyone. presents all health information in line with our terms and conditions. It is essential to understand that the medical information available on our platform is not intended to substitute the relationship between a patient and their physician or doctor, as well as any medical guidance they offer. Always consult with a healthcare professional before making any decisions based on the information found on our website.
Klarity is a citizen-centric health data management platform that enables citizens to securely access, control and share their own health data. Klarity Health Library aims to provide clear and evidence-based health and wellness related informative articles. 
Klarity / Managed Self Ltd
Alum House
5 Alum Chine Road
Westbourne Bournemouth BH4 8DT
VAT Number: 362 5758 74
Company Number: 10696687

Phone Number:

 +44 20 3239 9818