Calcipotriol ointment and cream or their vehicles applied immediately before irradiation inhibit ultraviolet B-induced erythema

Vitamin D Supplementation Does Not Improve the Severity or the Resolution of Ultraviolet B-Induced Acute Erythema

BACKGROUND

Whether vitamin D supplementation alleviates the severity of ultraviolet B (UVB)-induced erythema and/or facilitates its resolution remains undetermined.

OBJECTIVE

To study the effect of oral vitamin D on UVB-induced erythema and its resolution in fair-skinned subjects.

METHODS

UVB-induced erythema was quantified using a Chroma Meter® in 50 volunteers 48 h before and 10 days after the random administration of 200,000 IU vitamin D (n = 40) or placebo (n = 10). Resolution of erythema in both groups was assessed by chromametry 24, 48, and 72 h after vitamin D administration.

RESULTS

No statistical difference between erythema values before and after administration in the vitamin D-supplemented group (p = 0.44) or the placebo group (p = 0.34) was noted. No statistical difference was evident between both groups with respect to resolution of erythema (p = 0.30).

CONCLUSION

Oral vitamin D supplementation neither improves protection against UVB-induced erythema nor facilitates its resolution.

Effects of Calcipotriol Cream and Ointment, Clobetasol Cream and Ointment and Tretinoin Cream on the Erythemogenicity of UVB

Various studies have shown the blocking effects of topical agents on UVB penetration, which can be used in combination with phototherapy. In this study, the photoprotective effects of 0.005% calcipotriol, 0.05% clobetasol-17-propionate, and 0.1% tretinoin, which can be used in combination with broad-band UVB, were investigated in an in vivo test. In a study group of 20 patients, phototests were performed to determine minimal erythema doses (MED) and the tests were repeated with thin (0.1 cc/25 cm2) and thick (0.3 cc/25 cm2) calcipotriol, clobetasol-17-propionate, and tretinoin in cream forms and sunscreen. After determining the MED, the test was repeated in another 20 patients with thin and thick calcipotriol and clobetasol-17-propionate in both cream and ointment forms and sunscreen. MED was increased with thin and thick applications of all agents. Moreover, the photoprotective effects of each agent increased with their thick applications compared with thin ones. The application of calcipotriol cream and ointment, clobetasol cream and ointment, and tretinoin cream, all of which can block UVB, is not recommended just before phototherapy.

Randomized double-blinded placebo-controlled intra-individual trial on topical treatment with a 1,25-dihydroxyvitamin D₃ analogue in polymorphic light eruption

BACKGROUND

Polymorphic light eruption (PLE) is a very frequent photodermatosis whose pathogenesis may involve resistance to ultraviolet (UV)-induced immune suppression. Similar to UV radiation, calcitriol (1,25-dihydroxyvitamin D₃) and its analogues such as calcipotriol have been shown to exhibit immunosuppressive properties.

OBJECTIVES

We performed a randomized double-blinded placebo-controlled intraindividual half-body trial (NCT00871052) to investigate the preventive effect of a calcipotriol-containing cream in PLE.

METHODS

Thirteen patients with PLE (10 women, three men; mean age 37 years) pretreated their skin on two symmetrically located test fields with calcipotriol or placebo cream twice daily for 7 days before the start of photoprovocation testing with solar-simulated UV radiation. We established a specific PLE test score [AA + SI + 0·4 P (range 0-12), where AA is affected area score (range 0-4), SI is skin infiltration score (range 0-4) and P is pruritus score on a visual analogue scale (range 0-10)] to quantify PLE severity.

RESULTS

Photoprovocation led to PLE lesions in 12/13 (92%) patients. As shown by the PLE test score, compared with placebo calcipotrial pretreatment significantly reduced PLE symptoms in average by 32% (95% confidence interval 21-44%; P = 0·0022, exact Wilcoxon signed-rank test) throughout the observation period starting at 48 h until 144 h after the first photoprovocation exposure. At 48, 72 and 144 h calcipotriol pretreatment resulted in a lower PLE test score in 7 (58%), 9 (75%) and 10 (83%) of the 12 cases, respectively. Considering all time points together, calcipotriol diminished the PLE test score in all 12 photoprovocable patients (P = 0·0005; Wilcoxon signed-rank test).

CONCLUSIONS

These results suggest a potential therapeutic benefit of topical 1,25-dihydroxyvitamin D₃ analogues as prophylactic treatment in patients with PLE.

A randomized, double-blind, negatively controlled pilot study to determine whether the use of emollients or calcipotriol alters the sensitivity of the skin to ultraviolet radiation during phototherapy with narrowband ultraviolet B

BACKGROUND

There is contradictory evidence suggesting that emollients increase, decrease or have no effect on minimal erythema dose (MED) or minimal phototoxic dose values prior to phototherapy. Few studies have looked at the in vivo use of emollients or calcipotriol prior to narrowband ultraviolet (UV) B (NB-UVB) treatment.

OBJECTIVES

To investigate whether emollients or calcipotriol alter MED readings of skin on the back of healthy subjects prior to NB-UVB irradiation.

METHODS

Topical agents were applied to the backs of 20 healthy volunteers for 30 min prior to MED testing. These agents were aqueous cream, 50:50 white soft paraffin and liquid paraffin, Diprobase(®) (Schering-Plough, Welwyn Garden City, U.K.), Epaderm(®) (Medlock, Oldham, U.K.) and calcipotriol ointment and cream. A control MED strip was used with no topical agent applied prior to testing. MED readings were recoded as integer steps between 1 and 9 (one is lowest MED dose for skin type; eight is highest; nine is no response, i.e. a higher MED).

RESULTS

The median MED was between step 5 and 6 for all treatments and control. There was no significant difference at the 5% level between control and each topical agent. The study was powered to detect a median difference of approximately 0·4-0·6 steps.

CONCLUSIONS

This has important implications at a practical level when advising patients not to apply creams prior to treatment with NB-UVB. Studies where agents are applied immediately prior to phototherapy have been more likely to show that emollients block transmission of UV radiation. If they are applied at least 30 min prior to treatment, they have no effect.

Effects of some emollients on the transmission of ultraviolet

BACKGROUND/PURPOSE

Various topical agents which can be used in combination with phototherapy may have blocking or enhancing effects. In this in vivo study, the effects of topical petrolatum, basis cream, glycerine and olive oil on the transmission of ultraviolet B (UVB) were investigated.

METHODS

A phototest was performed to determine the minimal erythema dose (MED) on 32 volunteers and the test was repeated with white petrolatum, basis cream, glycerine, olive oil and sunscreen (0.3 cm3/25 cm2). The effects of each agent on MED was determined after 24 h.

RESULTS

MEDs were increased with the application of white petrolatum and basis cream. However, MEDs were not changed with the application of glycerine and olive oil.

CONCLUSION

The application of white petrolatum and basis cream, which have blocking effects, immediately before UVB therapy is not recommended. However, glycerine and olive oil, which does not have any effect, can be used before phototherapy.

Phototherapy with narrowband vs broadband UVB

Phototherapy with ultraviolet (UV) radiation of wavelengths between 280 and 320 nm (UVB) is a safe and effective treatment for a variety of diseases. In addition to standard broadband UVB (bUVB), narrowband phototherapy with fluorescent bulbs emitting near monochromatic UV around 311 nm (nUVB) has become an important treatment for diseases such as psoriasis, atopic dermatitis and vitiligo. In addition to these indications, the number of diseases for which nUVB phototherapy is reported to be effective is continuously growing. The differential effects of nUVB phototherapy in comparison to other UV wavelengths as well as established and new indications for this treatment modality are reviewed.

Review of therapy of psoriasis: the prebiologic armamentarium

This article discusses the prebiologic armamentarium, which continues to play a significant role in certain patients for the treatment of psoriasis. With the creation of the newer"biologics," however, the treatment of psoriasis is being re-evaluated.

Topical calcitriol is degraded by ultraviolet light

Calcitriol ointment has been approved for the treatment of psoriasis in many countries around the world. It may be prescribed in conjunction with phototherapy. Our purpose was to evaluate the effect of various therapeutic ultraviolet modalities on the stability of calcitriol and, conversely, to study the effects of calcitriol ointment on transmission of different forms of ultraviolet light. Calcitriol ointment 3 microg per g was irradiated with 10 J per cm2 ultraviolet A, 100 mJ per cm2 broadband ultraviolet B, and 3.0 J per cm2 narrowband ultraviolet B, and its stability was compared with samples exposed to fluorescent light and ambient sunlight. Ultraviolet A and ultraviolet B transmission were measured through thin and thick layers of calcitriol 3 microg per g ointment and vehicle. More than 90% of calcitriol ointment is degraded upon exposure to ultraviolet A, broadband ultraviolet B, and narrowband ultraviolet B. Transmission of ultraviolet A is reduced through calcitriol ointment and its vehicle by 17%-31% and 17%-41%, respectively. Transmission of ultraviolet B is reduced by 67%-87% through vehicle and 50%-83% through calcitriol ointment. When used in conjunction with phototherapy, calcitriol ointment should be applied after ultraviolet exposure, not before. Calcipotriene, the only vitamin D analog already approved for psoriasis in the USA, has been used successfully in combination with ultraviolet B and psoralen plus ultraviolet A.

Vitamin D and the skin

Vitamin D was originally discovered as a factor that regulates calcium and bone metabolism. Recent advances in investigation have shown that vitamin D also functions as a regulator of cellular growth and differentiation in various tissues. The skin is not an exception from such effects of vitamin D; it is regarded as a site of its activation and action. Evidence has accumulated showing that the active form of vitamin D and its analogs suppress growth and stimulate the terminal differentiation of keratinocytes. In psoriatic lesions, epidermal keratinocytes exhibit hyper-proliferation and impaired differentiation triggered by inflammation. Therefore, it is quite reasonable that vitamin D is effective on psoriasis. Indeed, within the past decade, analogs of vitamin D3 have been used as topical therapy for psoriasis. In this review, we summarize the fundamental features of vitamin D and the development of vitamin D therapy for psoriasis. Clinical application to other skin diseases and the future of vitamin D therapy in dermatology are also discussed.

Combination therapy with vitamin D analogues

Monotherapy with vitamin D analogues has been shown to be effective in the treatment of psoriasis. Vitamin D analogues have also been used in combination with other topical therapies, systemic therapies and phototherapy. In many instances, the efficacy of these other treatments can be maximized and adverse effects minimized when combined with vitamin D analogues. The combination of a topical corticosteroid with a vitamin D analogue can work synergistically to improve efficacy and reduce the side-effects from both treatments. However, caution must be used when mixing the two agents, as some topical corticosteroids will result in the degradation of the vitamin D analogue. Benefit from phototherapy is also increased when using vitamin D analogues, so that greater improvement occurs with fewer treatments. Effects on minimal erythema dose must be considered and the potential for ultraviolet blocking by vitamin D analogues may affect treatment. Some vitamin D analogues may also be susceptible to degradation by certain wavelengths of ultraviolet light. Combining vitamin D analogues with systemic agents exerts a dose-sparing effect, thus reducing the possibility of side-effects, but such combinations require further study. As long as treatments are used correctly, the benefits of combination therapy with vitamin D analogues usually outweigh the few drawbacks.