UVB Phototherapy Helps Psoriasis


Does it work?  Is it Safe? 

This article will explain how UVB phototherapy works to clear up psoriasis plaques, and how you can manage your treatment at home, which can be so liberating. 

We’ll will also cover a wide range of psoriasis triggers to avoid or manage, which can significantly reduce the number and severity of your psoriatic flare-ups.


What’s Happening to Your Skin?

Psoriasis is a chronic disease that causes skin cells to grow too quickly, resulting in thick, white, silvery, or red patches of skin. 

Normally, skin cells grow gradually and flake off about every 4 weeks. New skin cells grow to replace the outer layers of the skin as they shed; but in psoriasis, new skin cells move rapidly to the surface of the skin in days rather than weeks.

When the rapidly growing new skin cells build up, they form thick patches called plaques. These plaques range in size from small to large.

Psoriasis plaques most often appear on the knees, elbows, scalp, hands, feet, or lower back.

Psoriasis is most common in adults but children and teens can get it too.



Having psoriasis can be frustrating and embarrassing, and many people avoid certain types of clothing,  swimming and other situations where patches can show.


The good news is ..


Phototherapy Clears Psoriasis Plaques



Scientific studies have shown that phototherapy in particular, is a very effective treatment to speed the healing of psoriatic plaques.

As one recent study stated:


Phototherapy provides good control of clinical symptoms in the short term for patients with moderate-to-severe plaque-type psoriasis that have failed or are unresponsive to management with topical agents.


Types of Light Therapy (Phototherapy)


Phototherapy uses natural or artificial ultraviolet light. The simplest and easiest form of phototherapy involves exposing your skin to controlled amounts of natural sunlight.

Other forms of light therapy include the use of artificial ultraviolet A (UVA) or ultraviolet B (UVB) light, either alone or in combination with medications.




Exposure to ultraviolet (UV) rays in sunlight slows skin cell turnover and reduces scaling and inflammation.

Brief, daily exposures to small amounts of sunlight may improve psoriasis, but intense sun exposure can worsen symptoms and cause skin damage.

Before beginning a sunlight regimen, ask your doctor about the safest way to use natural sunlight for psoriasis treatment.


Home UVB Phototherapy for Psoriasis



Controlled doses of UVB light from an artificial light source improves mild to moderate psoriasis symptoms.

Studies have shown this treatment to be well tolerated, efficacious, and economical.

UVB phototherapy, also called broadband or midband UVB, can be used to treat single patches, widespread psoriasis and psoriasis that resists topical treatments.

UVB can also be combined with other topical and/or systemic agents to enhance efficacy, but some of these may increase photosensitivity and burning, or shorten remission. Combining UVB with systemic therapies may increase efficacy dramatically and allow for lower doses of the systemic medication to be used.

Treating psoriasis with a UVB light unit at home is an economical and convenient choice for many people. Like phototherapy in a clinic, it requires a consistent treatment schedule. Individuals can be treated initially at a medical facility and then begin using a light unit at home.

It is critical when doing phototherapy at home to follow a doctor’s instructions and continue with regular check-ups. Home phototherapy is a medical treatment that requires monitoring by a health care professional.  Appropriate clinic follow-up when using home UVB phototherapy is at least once every 3 months.


Managing UVB Phototherapy at Home


A standard protocol for UVB phototherapy is treatment would be 3 sessions per week with a minimum of 24 hours between sessions. Treatment every other day is effective for most patients.

Patients shwould instructed to dose phototherapy as per treatment protocol prescribed by their physician, and to use proper technique as taught during outpatient phototherapy and home phototherapy orientation.

Moisturizer should be immediately applied following treatment to prevent excessive dryness and subsequent itching.

Short-term side effects may include redness, itching and dry skin. Using a moisturizer may help decrease these side effects.


A 2016 Study of Broadband (Midband) UVB Phototherapy for Psoriasis States:


“Although phototherapy is one of the oldest therapeutic modalities for psoriasis, it remains a mainstay treatment…”


A 2010 Study Summarized:


Home phototherapy is a well-tolerated, efficacious, economical and patient friendly therapeutic option. Advantages of home phototherapy include improved quality of life, greater convenience, lower cost, and less time lost from work and social activities. Dermatologists should strongly consider home phototherapy as a first-line treatment option for appropriately selected psoriasis patients.


Rayminder Model 2 Midband UVB Lamp Home UVB Midband (Broadband) Light


The Model 2 Midband UVB Lamp is the most popular UVB lamp from Rayminder. 

The Model 2 has a programmable memory and an active digital countdown displayed on a blue touchscreen, and comes with protective glasses, adjustable stand, UV detect beads, mounting screws, and instructions for the timer.


Narrow Band UVB Phototherapy

A newer type of psoriasis treatment, narrow band UVB phototherapy may be more effective than broadband UVB treatment.

NB-UVB phototherapy is a good alternative for patients with fairly extensive disease.

It’s usually administered in a a clinic, two or three times a week until the skin improves, and then maintenance may require only weekly sessions.


Narrow Band UVB Treatment Protocol

With NB-UVB, patients normally stand in a phototherapy unit containing a bank of 48 fluorescent tubes.

For limited hand or foot disease, patients sit with the affected areas placed in a specific hand and foot device.

Therapy is administered 2-3 times a week, on nonconsecutive days.

Affected segments of the skin are exposed during each treatment, and a predetermined starting dose of light is administered, with subsequent increases of approximately 10-15% for each treatment.

If the patient reports mild redness or itching, the irradiation dose is held constant for the subsequent treatment, or until resolution of symptoms. If burning, pain or blistering develops, the irradiation dose is usually decreased by 10-15%.

Typically, once 75% repigmentation is achieved, the frequency of treatments is tapered to twice a week for 4 weeks, then weekly for 4 weeks.


Side Effects of Narrow Band UVB Phototherapy

The side effects of narrow band UVB phototherapy can be more severe than the midband UVB above.


You may experience some of these short-term side effects:

  • Burning – usually this is mild. If more severe, we will adjust the dose. Do not go to the beach or use a solarium while being treated – severe burning may develop.
  • Development of a rash brought on by exposure to UVB (rare)
  • Precipitation of a cold sore. (If you are susceptible and the area where they occur is exposed to the UVB). Protect the area where cold sores with zinc oxide or titanium dioxide containing sunscreens.
  • Some people find their skin becomes drier during treatment. Moisturising the skin regularly and reducing the use of soap in the shower reduces this dryness.
  • When the Psoriasis or Eczema gets better there is often a darkening of the skin where the problem was. The darkening is temporary but may take some weeks or months to go away.


Possible Long term Side Effects

  • Premature ageing of the skin with wrinkling, dilated capillaries, dryness, pigmentary changes and loss of elasticity.
  • NBUVB can contribute or add to an individual’s overall lifetime risk of developing skin cancer. This includes sunspots, non melanoma skin cancer (Basal and Squamous Cell Carcinomas) and perhaps Melanoma.
  • There may be a greater risk of developing Melanoma but we do not have any data at this time.
  • Regular attendance for treatment is important to get the best results. If you miss too many appointments the phototherapy nurse will stop your treatment and ask you to see your dermatologist to discuss other treatment alternatives. Further phototherapy may be scheduled when you are able to attend regularly.


Goeckerman Therapy

Some doctors combine UVB treatment and coal tar treatment, which is known as Goeckerman treatment. The two therapies together are more effective than either alone because coal tar makes skin more receptive to UVB light.

Standard therapy includes use of 2–4% crude coal tar in a petroleum base applied daily to the psoriatic plaques.

The minimum period of time for tar application is 2-hours, although it has been recognized that greater periods of time produce better results. 

The patient is then exposed to broad-band ultraviolet B (UVB) radiation, although narrow-band UVB may also be used.



Studies show that the Goeckerman regimen is effective in treating patients with both plaque psoriasis and eczema. The treatment is tolerated well, and is accepted as effective and safe.


Psoralen Plus Ultraviolet A (PUVA)

This form of photochemotherapy involves taking a light-sensitizing medication (psoralen) before exposure to UVA light. UVA light penetrates deeper into the skin than does UVB light, and psoralen makes the skin more responsive to UVA exposure.

A study published in April 2013 in the American Journal of Clinical Dermatology found that PUVA therapy was most effective among adults with moderate to severe plaque psoriasis. According to the study, between 60 and 75 percent of patients overall who received some type of light therapy achieved at least 75 percent improvement in their condition.

The results were based on the Psoriasis Area and Severity Index, an assessment tool used to score a person’s condition according to disease progression.

PUVA treatment is more aggressive, and consistently improves skin.  It is often used for more-severe cases of psoriasis.

Short-term side effects include nausea, headache, burning and itching. Long-term side effects include dry and wrinkled skin, freckles, increased sun sensitivity, and increased risk of skin cancer, including melanoma.

Note: If you are interested in grading the severity of your psoriasis, you can use this free online Psoriasis Area and Severity Index [PASI].


Excimer Laser for Psoriasis

This form of light therapy, used for mild to moderate psoriasis, treats only the involved skin without harming healthy skin.

The excimer laser has been shown to be effective in difficult to treat psoriasis like palmoplantar pustular psoriasis, scalp, and nail psoriasis.


Excimer Laser Protocol

Excimer laser treatments are performed in the dermatologist’s office. Each session takes only a few minutes. During the treatment, the doctor aims the laser directly at patches of psoriasis.



A controlled beam of UVB light is directed to the psoriasis plaques to control scaling and inflammation.

Excimer laser therapy requires fewer sessions than does traditional phototherapy because more powerful UVB light is used. Side effects can include redness and blistering.

As this study found, although the laser has demonstrated clinical efficacy, there is a lack of literature outlining its safety and efficacy.


Important Phototherapy Cautions


For people who have erythroderma or pustular psoriasis, UV treatment may make the condition worse.  Consult with your doctor.


Erythroderma, or exfoliative psoriasis, is an extremely rare form that may be disabling or fatal. People with erythroderma may have:

  • Symptoms that affect the entire body, not just the skin.
  • Inflammation and redness on skin all over the body. The skin may shed or slough off and is usually itchy and painful.
  • Chills and inability to regulate body temperature.


Pustular psoriasis symptoms include:

  • Fluid-filled (non-infectious pus) sores that appear on the palms of the hands and soles of the feet. The skin is very scaly.
  • Larger affected areas of skin (plaque) or small, drop-sized sores that may also appear on other body parts.
  • Nail changes.
  • Flares that occur after you stop taking certain medicines (such as high-strength corticosteroid creams).


Psoriasis Triggers – Avoidance and Management


In addition to understanding how phototherapy may help, it is important to be aware of, and avoid the triggers which may bring on or aggravate a psoriasis flare-up in the first place.


Psoriasis is a Genetic Autoimmune Disease


Scientists believe that at least 10 percent of people inherit one or more of the genes that could eventually lead to psoriasis.


But only 2 percent to 3 percent of the population develops the disease.




Researchers believe that for a person to develop psoriasis, that person must have a combination of the genes that cause psoriasis and be exposed to specific external factors known as “triggers.”




  • Studies show that stress is a common trigger of psoriasis flares; however, psoriasis flares also cause stress.
  • Stress increases inflammation in the body, and inflammatory compounds are damaging to body tissues.
  • People who have autoimmune conditions, such as psoriasis, seem to have immune systems that over respond and release an abundance of inflammatory compounds when stressed.
  • Women seem particularly vulnerable to experiencing psoriasis flares due to stress.


Psychic stress is associated with exacerbation of psoriasis, and more attention to mental well-being should be paid at least in the case of those psoriatic patients seeking actively for medical care.




Stress Management is Crucial

Controlling stress one of the most important ways to minimize the risk of future psoriasis flares. There are many methods to combat stress.

  • Deep diaphragmatic breathing engages the so-called “rest and digest” parasympathetic nervous system. Breathe in through your nose, slowly and deeply from your diaphragm. Hold the breath and then breathe out slowly through your mouth.
  • Exercise boosts mood, improves energy levels, and releases endorphins, feel-good chemicals associated with decreased pain. Regular exercise decreases anxiety and improves sleep. Women who exercise vigorously and less likely to develop psoriasis than women who are less physically active.
  • Enlist the help of a therapist or enroll in a stress management program to learn how to handle stress more effectively. A therapist may use cognitive behavioral therapy (CBT) to help you change thoughts and behaviors to keep your stress levels down.


Recommended Reading:

The Anxiety & Worry Workbook – The Cognitive Behavioral Solution

Lose Weight

Science has now proven that extra pounds affect psoriasis.





Minimize Alcohol Consumption



There is a link between alcohol consumption is associated with increased risk of psoriasis.


According to a 2013 study:


Epidemiological evidence suggests that patients with moderate to severe psoriasis have an increased incidence of alcohol-related diseases and mortality. This appears to be unique to psoriasis compared with other autoimmune diseases. Excessive alcohol consumption may contribute to systemic inflammation and the comorbidities associated with psoriasis, including cardiovascular disease and depression.


  • Alcohol consumption negatively impacts treatment and reduces the likelihood of remission.
  • Alcohol may also interact with certain psoriasis medications.


If you’re trying to cut back or stop drinking all together, managing triggers can help you reach your goal. In general, avoid high-risk situations where you anticipate it will be difficult to avoid temptation. If you can’t avoid a situation where you are concerned you might be triggered, have some strategies in place to help you stay on track and cope.



Dry Winter Air



A recent study examined the effect of weather conditions of people with psoriasis. It reported that most people with psoriasis who participated in the study had symptoms that improved in the summer and got worse during the winter, when humidity levels tend to be lower in the air is more dry.

The study did not find that muggy or rainy weather conditions had an effect on psoriasis symptoms, nor did it find any effect due to the indoor environment (for example, whether an air conditioner, radiator or fireplace was used). However, they did find that for some people with psoriasis, heat can worsen symptoms such as itching and redness.

The researchers conclude that some sun exposure tends to have a positive effect on symptoms for most patients.

The study suggests that:


The reason dry winter air tends to make symptoms worse is that the low humidity causes the top layer of the skin to become thicker, which triggers the production of substances in the immune system that cause inflammation.



Consider a Humidifier in Winter

While you can’t control the humidity outdoors, you can make sure your inside environment helps to replenish your winter-dry skin.  This will help ameliorate the effects of the dry winter air outside constant exposure to dry heated air inside.

“In the cold and bitter winter months, skin is unable to hold onto moisture in the same way it can during warmer seasons,” says Dr. Emily Wise, medical, surgical and cosmetic dermatologist of Krauss Dermatology, a private practice in Wellesley, Massachusetts.

“Both lower humidity in the cold outdoor air and dry heat inside our homes lead to an increase of water loss from the skin,” Dr. Wise adds, which, in turn, leaves us feeling itchy and dry. Humidifiers can help replenish this moisture loss and even soothe harsh skin conditions like eczema or psoriasis.


Example: Pure Enrichment MistAire Ultrasonic Cool Mist Humidifier



Use a Heavy, Hypoallergenic Moisturizer

Using heavy moisturizers can also help fight dry skin and reduce the discomfort from winter psoriasis. Choose moisturizers and skin products that are fragrance-free, hypoallergenic, and formulated for sensitive skin.


Cetaphil Moisturizing Cream for Dry/Sensitive Skin, Fragrance Free 16 oz (Pack of 2)
Example: Cetaphil Body Moisturizing Cream for Dry, Sensitive Skin. Fragrance Free.

Tattoos, The Koebner Phenomenon, and Skin Trauma



You may like the look of tattoos, but they may not be a good idea if you have psoriasis.

Piercing the skin and injecting dye underneath the skin is associated with skin trauma that may trigger psoriasis.

Some people who have psoriasis develop new psoriatic lesions 10 to 14 days after getting a tattoo. Tattooed skin may also become infected, and skin infections are also potential psoriasis triggers.


The Koebner Phenomenon

If you have psoriasis, there’s probably a lot you already do to take care of your skin. One thing your doctor has likely recommended is avoiding injury or trauma to your skin. 

One of the key features of psoriasis is chronic low-grade trauma in areas such as your elbows and knees, which is why those areas of common sites for psoriatic plaques.


The Koebner phenomenon (also known as Koebnerization or isomorphic response) occurs when a new area of psoriasis develops from injured skin. In cases of direct trauma, such as a cut or wound, your skin can Koebnerize or turn into psoriasis.


For example, after a surgery, psoriasis may develop around the surgical scar. This phenomenon may also help explain why psoriasis tends to occur on areas of constant low-intensity trauma such as elbows and knees.

Koebnerization can also occur after non-traumatic skin injuries such as a sunburn or an allergic reaction to a medication.

Likewise, if you have dandruff or seborrheic dermatitis on your face and scalp, you may develop psoriasis in these areas due to irritation and scratching as well as a crossover or combination dermatitis known as “sebopsoriasis.”

Koebnerization is not specific to psoriasis and can be seen with mosaic skin disorders like vitiligo as well.

For this reason, trauma to the skin needs to be avoided or minimized if you have psoriasis.


A variety of skin injuries have been found to trigger the Koebner phenomenon:


  • Bites: animal, insects
  • Burns: thermal, electrodessication, sunburn
  • Excoriation, friction: shaving
  • Freezing, cryotherapy
  • Lacerations: gunshot, needle scarification, surgical incisions
  • Pressure: orthotics, pressure sores , thumb-sucking, nail manicure


Chemical irritation
  • Positive patch test reaction
  • Tattoo-associated skin reactions
  • BCG, influenza vaccinations
  • Hair spray, hair dye allergy
  • Tuberculin skin test
  • Iodine reaction


The best way to avoid injury is to eliminate as many of these risk factors as possible.

  • When outside, stay covered and use an insect repellent to protect yourself from bites.
  • If you are undergoing a medical procedure, such as surgery or getting an injection, let your doctor or surgeon know you have psoriasis and ask if there are any ways to minimize skin trauma during the procedure.  
  • New lesions can also result from hives and other conditions affecting the skin. Koebnerization can also occur as a symptom of withdrawal from methotrexate therapy.
  • If you are concerned another skin condition or change in medications may be causing your psoriasis to worsen, speak to your doctor about ways to better manage your care and condition. 

Treat your skin kindly in order to keep it calm. Try not to participate in activities that increase your risk of skin trauma or injury. By minimizing your risk of trauma, you’ll be one step closer to preventing psoriasis outbreaks. 


Don’t Smoke



Smoking greatly increases the risk of psoriasis and makes the disease much worse, and studies have documented that approximately 20% of cases of psoriasis are related to smoking.


3 large cohort studies found a consistent association between smoking and the risk of psoriasis, showing that smoking is an independent risk factor for psoriasis.


Compounds in cigarette smoke negatively impact the immune system and the growth of skin cells to promote psoriasis. The more cigarettes a person smokes per day, the greater his or her risk of developing psoriasis.


Smoking and Psoriasis Statistics

Smoking increases the risk of developing of psoriasis and it increases the severity of the disease.


Studies suggest that women who are smokers have an up to 3.3-fold increased risk of developing plaque-type psoriasis. Men psoriasis patients who are smokers  show a more severe expression of disease in their extremities.


Obviously, smoking isn’t good for anyone, but it’s especially important to quit smoking if you have psoriasis.


Your Hormone Balance



Anyone of any age can get psoriasis but the condition most commonly occurs in people between the ages of 20 and 30 and in those over the age of 50.

It is believed that hormone changes at those times precede the onset of psoriasis.

Hormones influence the severity of the condition. Hormone changes in pregnancy result in decreased psoriasis symptoms in more than 50% of women at 30 weeks of gestation and a worsening of symptoms in more than 20% of women.¹

Studies show that sex hormones and prolactin, as well as many other hormones, are known to affect the development and severity of psoriasis.


Hormones that have an effect on psoriasis include:


  • estrogen,
  • progesterone,
  • cortisol,
  • epinephrine,
  • prolactin,
  • thyroid hormones,
  • leptin,
  • ghrelin, and
  • insulin.


One study concludes that:


Hormonal assessment should be performed in patients with psoriasis, in order to correctly diagnose and treat pathologies that may be related with psoriasis exacerbations.


If you suspect out-of-whack hormones are contributing to your psoriasis symptoms, see your doctor or an endocrinologist to discuss your concerns.



Final Thoughts

Psoriasis can be a challenging disease.  While there is not yet a cure, there are things you can do to heal and minimize psoriasis flare-ups.

Avoid triggers wherever possible, and consider phototherapy to speed the healing of your existing psoriatic plaques.


Thanks for visiting!

I hope this article provided you some useful information on phototherapy and trigger management for psoriasis.

Your comments are most welcome!

What to Read Next



  1.  Clujul Medical, vol 89, 2016: “The Role of Hormones in the Pathogenesis of Psoriasis Vulgaris”
  • Gudjonsson JE, Elder JT (2012). Psoriasis. In LA Goldman et al., eds., Fitzpatrick’s Dermatology in General Medicine, 8th ed., vol. 1, pp. 197-231. New York: McGraw-Hill.
  • Habif TP, et al. (2011). Psoriasis and other papulosquamous diseases. In Skin Disease: Diagnosis and Treatment, 3rd ed., pp. 120-153. Edinburgh: Saunders.
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2 years ago

What a fantastic post, so much useful information. There are three points that you mention in this article that have me that ‘haaaa’ moment. I suffer with Anxiety, I used to smoke and I never attributed these to causing my psoriasis. I have given up smoking now but still suffer from anxiety, and it does correlate with my psoriasis flaring up. So that was some learning from your article, but I also did not know that there was such a thing as light therapy. It sounds like a safer alternative to using steroid creams. The units look quite compact and… Read more »

2 years ago
Reply to  Darrin

Thanks for your comment, Darrin.  Start by asking your doctor if he or she feels you would benefit from UVB light therapy sessions.  Whether or not to do so at home should be a decision based on the treatment plan your doctor thinks is best, and the potential cost and inconvenience of treatment at a specialist’s office.  My personal feeling is that if you can do the treatment properly (and under your physician’s guidance) at home, it’s less expensive, more convenient, and more empowering.

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