The inflammatory response to anthralin

The inflammatory dose-response of the skin to topical anthralin was measured in patients with psoriasis, and compared with the response in a group consisting of normal subjects and patients with unrelated skin diseases. Wide individual variation was demonstrated but there was no significant difference between individuals with and without psoriasis nor was there any significant association with age, sex, skin type and original thickness or cigarette smoking.     

Dithranol (anthralin) in psoriasis

Biopsies from affected skin of sixty-two patients with stable psoriasis were investigated by in vitro labelling with tritiated thymidine and by routine histological techniques. In the same patient there were considerable variations in the number of DNA-synthesizing cells in biopsies taken from different but similarly located lesions of the same macroscopic appearance, whereas variations in the number of DNA-synthesizing cells in biopsies taken from the same lesions were less pronounced. With due regard given to this finding, it is shown that treatment with dithranol for 1 and 2 weeks significantly reduces the number of DNA-synthesizing cells. There was an inverse relationship comparing the development of the granular layer with the number of DNA-synthesizing cells and parakeratosis. The variations in the number of DNA-synthesizing cells in different lesions in the same patient may also have implications for paired comparisons of topical treatment efficiency.     

Anthralin for psoriasis: Short-contact anthralin therapy compared with topical steroid and conventional anthralin

Anthralin is an effective topical drug for psoriasis therapy. Recent studies have suggested that anthralin may be effective in high concentrations for short periods of skin contact. The purpose of these studies was to compare psoriasis improvement rates in patients treated with 0.3% anthralin ointment for 10 minutes' skin contact daily with patients treated with a topical steroid, difluorosone diacetate. A further study conducted was a bilateral paired comparison between conventional strength (0.1%–0.5%) anthralin ointment overnight with high concentration anthralin (0.5%–3%) for short contact periods of 10 minutes daily. The results showed good responses in all treatment groups. Short-contact anthralin is confirmed as a practical means of outpatient therapy for psoriasis.     

Relationship between skin type and erythemal response to anthralin

Anthralin erythema dose-response curves were drawn for thirty adult patients of various skin types who had chronic plaque psoriasis. A small statistically significant difference was observed between the curves for skin types I and IV but this was not thought to be sufficient to account for the clinical impression of increased anthralin irritancy in fair-skinned subjects.     

Short-contact anthralin therapy for psoriasis using an aqueous cream formulation

A pilot study of five patients was conducted using an aqueous anthralin cream (Drithocreme) and demonstrated that between twenty and forty minutes was an effective contact time to produce an improvement in induration of psoriatic plaques. In a further, bilateral controlled study, the anthralin cream was used to treat twenty patients with symmetrical chronic plaque psoriasis. The cream was applied to one side of the body overnight and then to the other side in the morning. Thirty minutes later it was washed off both sides in a bath or shower. The results indicated that both overnight and short-contact treatment were equally effective, and the short-contact treatment reduced staining and irritation.     

Topical anthralin for psoriasis vulgaris: evaluation of 70 Japanese patients

In order to determine the usefulness of anthralin in the treatment of psoriasis, we evaluated the effectiveness of topical anthralin therapy in patients with psoriasis vulgaris in our hospital. Seventy patients with plaque-type psoriasis (58 men and 12 women), aged 17-79 years-old (mean; 47.6 years-old), who were treated at the Department of Dermatology, Tokyo Medical and Dental University, between 1992 and 1999, were retrospectively evaluated. Mean psoriasis activity and severity index (PASI) score before therapy was 24.6. Patients were treated with 0.1-2.0% topical anthralin. Responses were determined by clinical examination. The mean PASI score decreased to 8.7 after three months. The most effective anthralin concentration was 0.4-0.5%. The overall response rate was 85.7%, complete remission was obtained in 21.4%, and partial remission in 64.3%. Ten patients (14.3%) were anthralin-resistant. In all patients who entered complete remission, recurrence was noted within six months after stopping anthralin. Minor skin irritation and pigmentation occurred in most of the patients; however, no severe side effects were noted during the treatment. Our study indicated that anthralin is effective for chronic plaque-type psoriasis.     

Increased anthralin irritation response in vitiliginous skin

Summary The irritation response to anthralin was studied using the chamber-testing technique in 17 patients with vitiligo. Anthralin concentrations of 0.1%, 0.5%, 1%, and 5% in lanette wax were applied to both vitiliginous and adjacent pigmented skin for 24 h. The extent of the erythematous reaction was evaluated on the 2nd day after application. The visual assessment of the paired anthralin patches indicated that the erythema was more intense in pigmented skin than in vitiliginous skin in 15 out of 17 patients. Chromometer readings, however, clearly indicated that the erythematous response was stronger in the vitiliginous skin than in the pigmented skin, confirming the known fact that the human eye is not accurate in the quantitative assessment of complex colors. Immunophenotypification of cellular infiltrates, using the combination of different monoclonal antibodies and the peroxidase technique, showed that inflammatory cell infiltrates caused by the anthralin exposure contained increased numbers of granulocytes and monocytes in vitiliginous skin when compared with normal skin. The percentage of T-cell subsets, Langerhans cells, and mast cells in the same infiltrates of both types of skin were similar. Our results are discussed in accordance with the view that anthralin-induced radical species of the pigmented skin can be neutralized by the scavenging properties of melanin.Part of this work was presented at the annual meeting of the European Society for Dermatological Research, 1987, at Amsterdam, The Netherlands     

Short contact anthralin therapy of psoriasis with and without UV-irradiation and maintenance schedule to prevent relapses

A short term anthralin application schedule was used at home in 42 patients with severe psoriasis. In another group of 21 patients treated at our day care center, UV-B irradiation was added when the surplus of anthralin had been washed off. Good healing results within 3-8 weeks were noted in most patients. To prevent relapses 31 patients continued the anthralin treatment once or twice a week after healing. In 15 cases this was combined with UV irradiation. One patient relapsed after a severe infection, but 16 others were observed for 6-9 months and 14 for 3-5 months without relapses. Irritation of non-affected skin is common especially at the beginning of the treatment and some staining of clothes and linen can occur. With proper information about this, the treatment is well accepted by the patient who generally finds it reasonably simple without the need of special protective dressings.     

Short contact anthralin in the treatment of psoriasis: a study of different contact times

Eighteen patients with chronic plaque psoriasis were investigated in two groups to determine the optimal contact time for the application of 2% anthralin, within the range immediate removal to removal at 20 min. It was found that clinical efficacy, assessed by times to plaque clearing, and side effects of treatment, i.e. erythema and staining, were independent of anthralin contact time. There seemed to be a relationship between erythema induction and skin type.     

Calcipotriol improves the response of psoriasis to PUVA

Summary Combining PUVA with other therapeutic agents which reduce the UVA dose required for clearance of psoriasis may be of benefit by reducing the long-term risk of cutaneous malignancy and by increasing the efficacy of treatment. We have therefore studied the effect of calcipotriol in 13 patients with plaque-type psoriasis who were about to start twice weekly PUVA. In each patient, from the start of PUVA treatment, two plaques on symmetrical body sites were selected for assessment. Calcipotriol ointment was applied to one twice daily, and placebo to the other. Response was assessed weekly for 6 weeks: an investigator, unaware of treatment allocation. compared psoriasis severity within each of the plaques, and blood flux was measured using a scanning laser-Doppler velocimeter. Of the 11 patients who completed the study, in nine the calcipotriol-treated plaque either cleared before the placebo-treated plaque ( n=7 ) or was consistently judged to be better (n = 2). From the third week of the trial, mean blood flux was significantly lower in the calcipotriol-treated plaques than in those treated with placebo. In the seven patients whose psoriasis was clear in at least one plaque at the end of the study period, there was a median reduction in UVA dose of 26·5% for calcipotriol compared with placebo. With the exception of one patient, the improved response was not associated with earlier relapse.     

Mechanism of anthralin inflammation I. Dissociation of response to clobetasol and indomethacin

The effect of topical clobetasol propionate and a 1% topical indomethacin gel which could inhibit UV erythema was measured on anthralin inflammation by change in skin-fold thickness and erythema. The time course of the inflammatory oedema and erythema were different, as was their response to the drugs studied. The oedema of anthralin inflammation was completely inhibited by clobetasol propionate but the erythemal response showed a small and non-significant reduction. Indomethacin had no effect on anthralin oedema but produced a small but significant reduction in erythema in the first 24 h after anthralin application. These results suggest that either anthralin inflammation is not due to production of prostenoids, or that if it is, it occurs by other than the classical enzymic pathway.     

Photochemotherapy for psoriasis remission times. Psoralens and UV-A and combined photochemotherapy with anthralin

Oral methoxsalen and long-wave ultraviolet light (PUVA) was evaluated in 187 psoriatics, with emphasis on remission and recurrence after therapy. The mean number of years psoriasis had been present was 18.3, the mean psoriatic involvement 34.8% the dose at the time of maximum clearance was 11.8 J/cm², and the mean number of treatments to achieve maximum clearance was 175. Complete clearance was achieved in sixty-one patients and in this group the average number of treatments to achieve maximum clearance was 16.8, the initial remission times ranged from 4 to 64 weeks, with an average of 21.6 weeks. In patients subsequently retreated, the remission time was only 12.4 weeks (57%), but the mean number of treatments to achieve maximum clearance was reduced (11.4) and patients responded more easily to treatment. Sixteen patients were treated in addition to PUVA, with anthralin in Lassars' paste with clearing achieved between six and fifteen treatments, a mean of 9.5. Combinations of PUVA with other forms of psoriatic treatment may also help to reduce the cumulative PUVA exposures.