Spectrophotometric intracutaneous analysis as an early non-invasive predictor of efficacy in the phototherapy of psoriasis.

BACKGROUND: Phototherapy is generally effective for psoriasis but individual responsiveness and optimal treatment duration for disease clearance are unpredictable. However, easy, rapid and non-invasive plaque assessment by spectrophotometric intracutaneous analysis (SIAscopy), a novel multispectral skin imaging technique, may now make prediction feasible. OBJECTIVES: The early prediction of psoriatic plaque clearance during phototherapy by SIAscopy. METHODS: Sixteen psoriatic plaques in 10 psoriasis patients were serially assessed SIAscopically during phototherapy for punctate dots representing the dilated papillary dermal blood vessels characteristic of active psoriasis, and the results compared with the clinical findings. RESULTS: All plaques showing full SIAscopic clearance at early follow-up also showed complete or almost complete clinical clearance, and remained the same thereafter. All showing no SIAscopic clearance at early follow-up showed at most partial clinical clearance, and also remained the same thereafter. All showing only partial SIAscopic clearance at early follow-up also showed just partial clinical clearance, but then generally progressed to full SIAscopic and clinical clearance. CONCLUSIONS: SIAscopy of psoriatic plaques at early follow-up during patient phototherapy enables good prediction of likely later clinical clearance, thereby potentially avoiding unnecessary further treatment. A larger confirmatory study is now needed.

Randomized double-blind trial of treatment of vitiligo: efficacy of psoralen-UV-A therapy vs Narrowband-UV-B therapy.

OBJECTIVE: To compare the efficacy of oral psoralen-UV-A (PUVA) with that of narrowband-UV-B (NB-UVB) phototherapy in patients with nonsegmental vitiligo. DESIGN: Double-blind randomized study. SETTING: Phototherapy unit in a university hospital. PATIENTS: Fifty-six patients with nonsegmental vitiligo. Interventions Twice-weekly therapy with PUVA or NB-UVB. MAIN OUTCOME MEASURES: The change in body surface area affected by vitiligo and the color match of repigmented skin compared with unaffected skin were assessed after 48 sessions of therapy, at the end of the therapy course, and 12 months after the end of therapy. RESULTS: The results in the 25 patients each in the PUVA and NB-UVB groups who began therapy were analyzed. The median number of treatments was 47 in the PUVA-treated group and 97 in the NB-UVB-treated group (P = .03); we suspect this difference was because of the differences in efficacy and adverse effects between the 2 modalities, such that patients in the NB-UVB group wanted a longer course of treatment. At the end of therapy, 16 (64%) of 25 patients in the NB-UVB group showed greater than 50% improvement in body surface area affected compared with 9 (36%) of 25 patients in the PUVA group. The color match of the repigmented skin was excellent in all patients in the NB-UVB group but in only 11 (44%) of those in the PUVA group (P<.001). In patients who completed 48 sessions, the improvement in body surface area affected by vitiligo was greater with NB-UVB therapy than with PUVA therapy (P = .007). Twelve months after the cessation of therapy, the superiority of NB-UVB tended to be maintained. CONCLUSION: In the treatment of nonsegmental vitiligo, NB-UVB therapy is superior to oral PUVA therapy.

Randomized double-blind trial of the treatment of chronic plaque psoriasis: efficacy of psoralen-UV-A therapy vs narrowband UV-B therapy.

OBJECTIVE: To compare the efficacy of oral psoralen-UV-A (PUVA) therapy with that of narrowband UV-B (NB-UVB) therapy in patients with chronic plaque psoriasis. DESIGN: Double-blind randomized study. SETTING: Phototherapy unit in a university hospital. Patients Ninety-three patients with chronic plaque psoriasis. Interventions Twice-weekly NB-UVB or PUVA therapy, starting at 70% of the minimum phototoxic or erythema dose, with 20% incremental increases. Patients were treated until clearance, up to a maximum of 30 sessions; those with clearance were followed up until relapse or for 12 months. MAIN OUTCOME MEASURES: Proportion of patients achieving clearance, number of treatments to clearance, and, among those with clearance, the proportion remaining in remission at 6 months. RESULTS: Patients with skin types V and VI had a lower rate of clearance than those with skin types I through IV (24% vs 75%; P = .001). In patients with skin types I through IV, PUVA was significantly more effective than NB-UVB at achieving clearance (84% vs 65%; P = .02). The median number of treatments to clearance was significantly lower in the PUVA group (17.0 vs 28.5; P<.001). More patients treated with PUVA vs NB-UVB were reported to have erythema at some stage during treatment (49% vs 22%; P = .004), although this difference may have been due to ascertainment bias. Six months after the cessation of therapy, 68% of PUVA-treated patients were still in remission vs 35% of NB-UVB-treated patients. Conclusion Compared with NB-UVB, PUVA achieves clearance in more patients with fewer treatment sessions and results in longer remissions.

Photoadaptation during narrowband ultraviolet-B therapy is independent of skin type: a study of 352 patients.

Understanding how photoadaptation differs between individuals is important when considering susceptibility to the beneficial and harmful effects of sunlight exposure and when determining optimal phototherapy regimens. Most narrowband UVB (NB-UVB) regimens start with 70% of the minimal erythema dose (MED) with 20% increments at each treatment thereafter. We retrospectively studied 352 skin types I-IV psoriatic patients having twice weekly treatment with this regimen. Patients with high skin types tended to have high MEDs (P<0.001). By session 20 the proportion of patients who had developed erythema was approximately 60% regardless of MED. Among patients who developed erythema, the number of treatments before erythema occurred did not differ between skin types (P=0.33). We conclude that patients with high skin types photoadapt approximately equally per physical unit of UVR in comparison to those with low skin types, but they have greater photoadaptation in absolute terms because they are able to tolerate a higher initial dose of radiation. Differences in skin type or MED are not associated with clinically important differences in tendency to erythema during a standard 70/20% NB-UVB twice-weekly regimen. This regimen is suitable for all skin types I-IV patients regardless of skin type or MED.

Photosensitivity disorders: cause, effect and management.

Abnormal photosensitivity syndromes form a significant and common group of skin diseases. They include primary (idiopathic) photodermatoses such as polymorphic light eruption (PLE), chronic actinic dermatitis (CAD), actinic prurigo, hydroa vacciniforme and solar urticaria, in addition to drug- and chemical-induced photosensitivity and photo-exacerbated dermatoses. They can be extremely disabling and difficult to diagnose. PLE, characterized by a recurrent pruritic papulo-vesicular eruption of affected skin within hours of sun exposure, is best managed by restriction of ultraviolet radiation (UVR) exposure and the use of high sun protection factor (SPF) sunscreens. If these measures are insufficient, prophylactic phototherapy with PUVA, broadband UVB or narrowband UVB (TL-01) for several weeks during spring may be necessary. CAD manifests as a dermatitis of chronically sun-exposed skin. Again, UVR exposure needs to be restricted; cyclosporine, azathioprine or PUVA may also be necessary. Actinic prurigo is characterized by the presence of excoriated papules and nodules on the face and limbs, most prominent and numerous distally. Actinic prurigo is managed again by restriction of UVR and the use of high SPF sunscreens; PUVA or broadband UVB therapy, or low doses of thalidomide may be necessary. Hydroa vacciniforme causes crops of discrete erythematous macules, 2 to 3mm in size, that evolve into blisters within a couple of days of sun exposure. Treatment for this rare disease is difficult; absorbent sunscreens and restricted UVR exposure may help. Solar urticaria is characterized by acute erythema and urticarial wealing after exposure to UVR. Treatment options for solar urticaria include non-sedating antihistamines such as fexofenadine and cetirizine; other options include absorbent sunscreens, restriction of UVR at the relevant wavelength, maintenance of a non-responsive state with natural or artificial light exposure and plasmapheresis. Industrial, cosmetic and therapeutic agents can induce exogenous drug- or chemical-induced photosensitivity. The clinical pattern is highly varied, depending on the agent; treatment is based on removal of the photosensitizer along with restriction of UVR exposure. Predominantly non-photosensitive dermatoses may also be exacerbated or precipitated by UVR; exposure to UVR should be reduced and sunscreens should be advocated, along with appropriate treatment of the underlying disease.