Psoriasis and phototherapy the psoriasis small itchy patches on skin and psoriatic arthritis alliance – papaa

Sunlight contains a wide range of wavelengths; more than just visible light. Long wavelengths, invisible to our eyes, are called infrared and we feel these as heat from small itchy patches on skin the sun. Shorter wavelengths are also invisible to us and these are small itchy patches on skin called ultraviolet (UV). They can cause suntan and sunburn, and also carry the risk of skin cancer to some small itchy patches on skin individuals after high- and long-term exposure.

Phototherapy cannot cure psoriasis; in some cases it will completely clear the skin, in others improve but not eliminate the plaques. Phototherapy is a second-line treatment, used in dermatology departments when first-line topical treatments (creams, lotions, ointments) have failed to deal with severe or widespread plaques or small itchy patches on skin particularly troublesome flare-ups.

Both forms of phototherapy are given as a course of small itchy patches on skin treatment over many weeks, where the time of exposure to the UV is gradually small itchy patches on skin increased to prevent burning the skin and to allow the small itchy patches on skin skin to acclimatise to the treatment. After a course of phototherapy the treatment is stopped; in some cases improvements last for more than a year, while in other cases the psoriasis may start to recur small itchy patches on skin after a few months or even weeks. Further courses of treatment may be given. It is not possible to predict how individuals will respond small itchy patches on skin or how long their response will last after the phototherapy small itchy patches on skin course ends. Psoriasis is the skin condition that responds best to phototherapy small itchy patches on skin and in most phototherapy units 60- 70% of the people attending are being treated for psoriasis.

The exact cause of psoriasis is not fully understood and small itchy patches on skin the effects of UV on the skin are complicated, so a precise explanation of how phototherapy works is not small itchy patches on skin possible. PUVA and UVB phototherapy may also work in slightly different small itchy patches on skin ways. However, a simplified description of the mechanisms of phototherapy will help small itchy patches on skin to explain some of its side effects and restrictions.

Taking a simplified model of psoriasis as an example, the too-sensitive skin immune system causes localised patches of inflammation and small itchy patches on skin the overproduction of skin cells, in turn causing the visible plaques. Phototherapy stops the overproduction of skin cells by either damaging small itchy patches on skin their DNA (UVB phototherapy) or by preventing the cells from dividing by ‘locking’ the DNA (PUVA phototherapy). It also suppresses the skin immune system to stop the small itchy patches on skin ‘psoriasis process’. The twin processes of interfering with DNA and suppressing the small itchy patches on skin immune system in the skin can also cause skin cancer, so phototherapy can increase cancer risk. Therefore to safely benefit from UV phototherapy it is best small itchy patches on skin administered under professional medical supervision.

To treat the whole body, a phototherapy cabin is used. This consists of a stand-in cabinet with 6-foot (1.8m) fluorescent tubes all around. These tubes give out the UV needed for phototherapy. Some people dislike the rather claustrophobic feeling of being inside small itchy patches on skin the cabinet, but most get used to it and a simple push small itchy patches on skin on the cabin door is sufficient to open the cabin small itchy patches on skin and stop the treatment. It is necessary to stand in the cabin for 5-15 minutes, although longer treatments can be split into several shorter exposure small itchy patches on skin times. Fans are built into the cabinet for ventilation and temperature small itchy patches on skin control. Smaller UV units are used for treating small areas of small itchy patches on skin the skin, such as the hands or feet.

UVB is the first-line phototherapy treatment, since, for the type of psoriasis for which it is suitable, it can be as effective as PUVA but has fewer small itchy patches on skin immediate side effects and is very much safer in the small itchy patches on skin long term. It is entirely safe in pregnancy and during breastfeeding and small itchy patches on skin is the preferred phototherapy for children. UVB does not penetrate the skin as deeply as the small itchy patches on skin UVA in PUVA phototherapy, so it is used to treat psoriasis plaques that are small itchy patches on skin not too thick or white.

Many centres will check the UV sensitivity of the person’s skin prior to a course of UVB phototherapy by small itchy patches on skin applying a range of 6-10 different doses of UVB to small (1cm) areas of normally unexposed skin. The next day, some of these areas will have developed a redness (like sunburn), while others will be unaffected. The lowest dose to produce just perceptible redness is known small itchy patches on skin as the minimal erythemal dose (MED). This process checks for any unusual sensitivity to UVB and small itchy patches on skin determines the UVB exposure dose (time in the cabin) for the first treatment. From this short exposure on the first visit, subsequent visits will feature increasing amounts of UVB. This allows the skin to become used to the UVB, in a similar way that one may gradually increase time small itchy patches on skin in the sun on holiday to avoid immediate sunburn.

Other centres may start phototherapy based on how each individual small itchy patches on skin recalls their skin reacting to sun exposure. This allows the person receiving treatment to be assigned a small itchy patches on skin phototype. The phototype ranges from type I, paleskinned individuals who burn easily and do not tan, through type IV, darker-skinned individuals who rarely burn and tan easily and darkly, to type VI, black skin. Some centres use tabulated dose increase schedules, designed to increase the dose as quickly as possible, taking no account of the UV sensitivity of the individual. All of these methods result in effective treatment of psoriasis. UVB can be used as a single treatment or in small itchy patches on skin combination with other topical or systemic medications as recommended by small itchy patches on skin a doctor or healthcare professional.

The most common immediate side effect of UVB phototherapy is small itchy patches on skin a mild sunburn reaction. This may be more likely if the person being treated small itchy patches on skin has been using other medications or herbal supplements which can small itchy patches on skin cause sensitivity to light. It is therefore important, before starting any course of any treatment, to inform the healthcare professional or doctor of any products small itchy patches on skin being taken. This sunburn reaction is usually not serious and the phototherapist small itchy patches on skin will adjust the dose of the next treatment or postpone small itchy patches on skin treatments until the redness has settled. Some people report itchiness in the early stages of treatment, but this should soon settle.

The long-term effects of phototherapy (both UVB and PUVA) include increased ageing (photoageing) of the skin and an increased risk of certain skin small itchy patches on skin cancers. In the 30+ years of the medical use of narrowband UVB phototherapy, increased skin cancer has not been reported. UVB causes very little photoageing. Nevertheless, if someone has had 500 or more UVB treatments it small itchy patches on skin is recommended that the risks and benefits of further UVB small itchy patches on skin are re-evaluated and their skin checked for signs of skin cancer.

PUVA stands for psoralen and UVA. Psolaren makes the skin more sensitive to light and enables small itchy patches on skin UVA to help many skin conditions, especially psoriasis. PUVA is the secondline phototherapy and is used when UVB small itchy patches on skin is not suitable. In PUVA therapy the psoralen is taken as tablets, or applied directly to the skin as a gel or small itchy patches on skin by soaking in a bath solution. The skin is then exposed to UVA.

Most PUVA is administered as bath PUVA, where the individual soaks in a warm bath containing psoralen small itchy patches on skin for 10- 15 minutes before exposure to UVA. This sensitises the skin directly, so there are no side effects of feeling sick or small itchy patches on skin need to protect the eyes, unlike with tablet PUVA. The sensitisation of the skin is, however, stronger with bath rather than tablet PUVA, so less time in the phototherapy cabin is needed.

Like UVB treatment, PUVA is administered in hospital phototherapy or physiotherapy units. As with UVB phototherapy, there are different methods for deciding on a starting dose small itchy patches on skin of UVA and how to increase the dose to a small itchy patches on skin therapeutically effective level. Some centres measure the sensitivity of the individual’s skin to PUVA by applying test doses to small small itchy patches on skin areas of skin, in a similar way to the MED test described previously. Because PUVA involves sensitising the skin before UV exposure, the sensitivity test is called the minimal photosensitivity dose (MPD) test. Other centres may use phototype-based treatment schedules or a table of doses.

Treatment times for bath PUVA are shorter than for tablet small itchy patches on skin PUVA and may range from less than a minute up small itchy patches on skin to 5-8 minutes, depending on the output of the PUVA cabin and the small itchy patches on skin dose scheme used. Tablet PUVA times may extend to 15 minutes or more. If any session produces a sunburn reaction, or if any other symptoms are reported, the subsequent doses may be altered.

Psoriasis usually clears after 15-25 treatments, which take 7-12 weeks when following a twice-a-week schedule or 10-16 weeks for a three-times-a-fortnight schedule. It is not possible to predict how long the improvement small itchy patches on skin achieved by a course of phototherapy will last. For some people, remission of longer than a year is possible, for others their psoriasis remains clear for some months before small itchy patches on skin beginning to return.

The phototherapist will carefully explain all of the possible side small itchy patches on skin effects of phototherapy before a course begins. The most common immediate side effect of PUVA phototherapy is small itchy patches on skin a mild sunburn reaction. This may be more likely if the individual has been small itchy patches on skin using other medications or herbal supplements which can cause sensitivity small itchy patches on skin to light, so it is important to tell the phototherapist of anything small itchy patches on skin being taken. This sunburn reaction is usually not serious, and the phototherapist will adjust the dose of the next small itchy patches on skin treatment or postpone treatments until the redness has settled. Some people report some itchiness in the early stages of small itchy patches on skin treatment, but this should soon settle. People on tablet PUVA may feel a little sick after small itchy patches on skin taking the tablets. This may be only a mild inconvenience but if it small itchy patches on skin is intolerable, an alternative tablet is available and may help. Taking the tablets will sensitise the eyes to UVA and small itchy patches on skin exposure to the sun may increase the risk of cataract small itchy patches on skin formation, so eyes must be protected from sunlight or other sources small itchy patches on skin of UVA for 12 hours or until night-time. After taking the tablets, patients should wear sunglasses or other UV protective eyewear, or avoid exposure to sunlight altogether.

The long-term effects of phototherapy (both UVB and PUVA) include increased ageing (photoageing) of the skin and an increased risk of certain skin small itchy patches on skin cancers. PUVA is more risky than UVB, and a long-term follow-up study of PUVA has identified that the risk of small itchy patches on skin skin cancer increases with treatments. PUVA is also more damaging to the structure of the small itchy patches on skin skin and causes more skin ‘sun damage’. If a patient has had 200 PUVA treatments in his/her lifetime then it is recommended that their skin is small itchy patches on skin carefully checked for skin cancer, and the risks of further PUVA are fully considered before small itchy patches on skin further treatments are recommended. For men, there is an extra risk of skin cancer of the small itchy patches on skin genital skin. For this reason it is very important to protect the small itchy patches on skin genitals from PUVA exposure. Although UVB has not had a similar long-term study, it is assumed that the risk to genital skin from small itchy patches on skin UVB exposure is similar to PUVA, so similar precautions should be taken.

• phototherapy dosing schedules aim to apply the maximum amount of small itchy patches on skin UV that the skin can tolerate, in order to maximise the therapeutic effect. So it is important that all other exposure to UV small itchy patches on skin is avoided. This means absolutely never using sunbeds while on phototherapy and small itchy patches on skin avoiding sunbathing or other sun exposure. People having PUVA will have extra photosensitisation of their skin small itchy patches on skin immediately and for some hours after each session, so should be especially careful about exposing their skin on small itchy patches on skin the day of treatment.

RELATED POSTS