Psoriasis Triggers

There are a number of common triggers for a flare up of psoriasis, although these can be different for different people.

Psoriasis is often spoken about as a condition that runs in families, or that is genetic. This is true, although the way it is ‘inherited’ is complex. Not all family members get psoriasis, and just having a gene that is linked to psoriasis does not necessarily mean you will develop the condition.

For most people, a ‘trigger’ causes psoriasis to develop. It can be difficult to pinpoint the trigger, and many people never work out what their trigger is. Some people may think that one particular trigger started their psoriasis, but find that other things make it worse, or cause a flare. Everyone with psoriasis is different, and so what affects one person’s psoriasis might not affect another. Not all of the triggers in this section will affect every person with psoriasis, but they are some of the most common.


Streptococcal infection (usually in the throat) is known to trigger guttate psoriasis – a form of psoriasis where small, raindrop-like scaly patches are widespread across the torso and limbs. This is usually self-limiting (meaning it goes away), but can take weeks or months to clear up. Some people never develop another form of psoriasis, however others will. People who are prone to repeated bouts of streptococcal infection are often advised to see their GP as soon as they notice a sore throat, as it is thought by some that early antibiotics can in some cases stop guttate psoriasis from developing.

Other infections or viruses do not have as clear a link to psoriasis, however some people do report their psoriasis getting worse during a period of other illness. Immunosuppressive infections, such as HIV, can also cause psoriasis to develop or flare.

Injury to skin

The appearance of psoriasis around an injury is known as Koebner’s Phenomenon, named after the man who first described it. Commonly, this occurs around a wound, or a surgical scar, for instance. However, the ‘injury’ does not always have to be particularly bad – psoriasis can develop around injection sites, piercings and tattoos, areas where shoes, clothing or jewellery rub the skin, and even from scratching the skin.

Not everybody who has psoriasis finds that this occurs. A person that finds they are prone to Koebner’s phenomenon, however, can take steps to reduce or prevent it happening – such as by wearing loose fitting clothing, and avoiding jewellery or accessories such as watches or belts that may rub. If injury to skin cannot be avoided – such as if a surgery or vaccination is needed, the individual should be ready to treat the psoriasis as it appears, and make sure that their GP or Dermatologist is aware.


It is accepted that stress can both trigger psoriasis and make existing psoriasis worse, and a large proportion of people with psoriasis do think that stress affects their psoriasis. At the Psoriasis Association, we often hear from people whose first instance of psoriasis followed a redundancy, bereavement, divorce or period of illness. ‘Stress’ is something of a catch-all term, which may be experienced during the major life events already described, but can also be experienced in connection with ‘positive’ events (such as a wedding, house move or change of job), or can be longer-term and of a more everyday nature – caused by busy lives, hectic schedules, and pressure at work, for example. You do not have to feel depressed, anxious or low to be stressed, although some people may experience these as well.

It is not always helpful to advise people to ‘avoid stress’ – for many of us this is not possible! But people who find stress is a trigger could look at what they can do to reduce stress in their lives, and make changes accordingly. They should also consider how they deal with stress. If someone feels overwhelmed and unable to cope – with their psoriasis, other aspects of their life, or both – they should certainly discuss this with their GP, who may be able to help.


A local pharmacist or practice nurse is able to advise on antimalarial products, and we strongly recommend that anyone with psoriasis seeks this type of medical advice before taking an antimalarial medication.

A number of different medications are known to trigger psoriasis – whether aggravating psoriasis that already exists, or triggering it to occur for the first time. One of the most significant is certain antimalarial drugs. The antimalarial chloroquine (found in Avloclor and Nivaquine, for example) should not be used for malaria prevention by travellers who have psoriasis, as it can cause psoriasis to flare severely very quickly. In some cases, it can also cause small amounts of psoriasis to change into generalised psoriasis (all over the body) or generalised pustular psoriasis (all over the body with sterile pus-filled pustules). Newer animoquinolines such as mefloquine (Lariam) do not appear to carry the same risk. Other commonly-used antimalarials such as proguanil (Paludrine and Malorone) carry no special hazards in psoriasis.

Other medications that have been known to cause psoriasis to worsen include lithium (used to treat depression and other mental health conditions), certain anti-arrhythmic drugs (used to treat abnormal heart rhythms) and certain beta blockers (used to treat heart disease and high blood pressure). If a person is taking any of these drugs and notices a worsening of psoriasis, they should discuss it with their doctor, as there may be an alternative that does not have the same effect on their psoriasis. However, in some cases it might not be possible to stop taking these treatments, and it is very important they are not stopped unless a doctor has advised this change.

Many people with psoriasis find that their skin improves when on steroid medication; either applied to the skin (for psoriasis or another skin condition), or taken as a tablet or injection (for a condition other than psoriasis). This is because steroids have an anti-inflammatory action, and therefore can reduce the inflammatory processes in the body that lead to psoriasis appearing on the skin. However, oral and injected steroid medication can cause psoriasis to become unstable and flare, especially when finishing the course. As with steroids applied to the skin, oral or injected steroids should ideally be ‘weaned off’ (gradually reducing the dose) rather than stopping abruptly, to reduce the risk of the psoriasis flare occurring.

It is advisable to make sure that any medical professional (doctor, nurse, consultant, pharmacist or other) is aware of your psoriasis and any other conditions you may have or medications you may be taking, before prescribing any other medications.


Although scientific research continues to look into the potential links between psoriasis and diet, as yet, research is still inconclusive. However, some people do believe that certain foods make their psoriasis worse or better, and feel that they have improved their skin through diet. Unfortunately, the apparently successful foods and diet regimes are many and varied and, as with other aspects of psoriasis, what works for one person does not always work for another.

If you would like to explore the effects of diet on psoriasis, the most straightforward way is to keep a food diary and note down any skin symptoms alongside. It should then be easy to notice any patterns.

Whilst the internet can be a great resource for connecting with other people who have the same condition, and sharing knowledge and experiences, there is also a lot of inaccurate and misleading information out there. Whilst every individual is of course entitled to try whatever they wish to improve their psoriasis, it is important to be aware of these bogus claims of ‘cures’, as they may be costly, unsafe and disappointing.


It is not uncommon to hear of someone’s psoriasis first appearing around the time of puberty, or around the menopause for older women. Many women find that their psoriasis improves whilst pregnant, although a small number find that the opposite occurs and their psoriasis gets worse. It is thought that fluctuating hormone levels can have an effect on psoriasis in some people, but this is based more on the experiences of people with the condition than actual evidence-based research.

Alcohol and smoking

There are plausible arguments for why drinking might affect psoriasis (alcohol is dehydrating, and therefore could dry skin out even more). Some studies have found that people with severe psoriasis are more likely to be heavy drinkers, but it is not known if this is a cause or effect of living with psoriasis. People who have a high alcohol intake may find that their psoriasis is worse. It is not safe to drink alcohol whilst using certain medications for psoriasis (such as methotrexate and acitretin) and so this should be discussed with the prescribing doctor when treatment is being planned.

Scientific research has found that smokers are more likely to develop psoriasis than non-smokers. Some studies have also suggested that people who smoke may also have psoriasis that is more severe or more widespread than non-smokers with psoriasis. Palmoplantar pustulosis (pustular psoriasis on the palms of the hands and soles of the feet) is closely associated with smoking.

Although links between psoriasis and smoking have been found, this of course does not mean that all people who smoke will develop psoriasis, or that all people with psoriasis are smokers.


The information on this page is also available in our triggers information sheet.

December 2017 (Review Date: December 2020)