Azathioprine pulse therapy to prolong remission of psoriasis

Abstract

Psoriasis, a common disease with variable clinical manifestation effect the quality of life. Prevalence of psoriasis varies from country to country, effect equally to male and female and all age groups. Pathogenesis of psoriasis seems to be genetically determined T-lymphocyte mediated disorder due to interaction between keratinocytes and lymphocytes. Various treatments used for treating psoriasis topical or systemic, clear the psoriasis lesions partially or completely, but are not able to produce prolong or permanent remission. Maximum remission period reported with all the known therapies are 1 year. Chief problem with all the therapies are relapses. Recently introduced azathioprine pulse therapy has been found to target specially to activated T-lymphocytes leading to long term remission and less organ toxicity. In this treatment azathioprine was used as intermittent high dose (IHD) i.e. 500 mg daily on 3 consecutive days repeated every month with continuous low dose azathioprine (CLD) 100 mg daily in between the IHD. It was divided into four phases. In phase I, treatment with IHD and CLD was continued till all the lesions of psoriasis clear. Methotrexate (MTX) 15-25 mg orally or subcutaneously weekly along with coal tar 6% was also given to clear the lesions fast. After all lesions clear patients enter into phase II where all the treatment is stopped except IHD and CLD which was given for 9 months to prevent any minor recurrence. At the end of 9 months if no recurrence occur IHD was stopped and patients take only CLD for another 9 months (Phase III). In phase IV CLD was also stopped and patients were followed up for any recurrence. With this therapy about 70 patients inter into phase IV i.e. remission for 1-10 years continuously after all treatment was stopped. Subsequently it was found clearing the psoriatic arthritis and nail changes in psoriasis also for prolonged period. Introduction Psoriasis a common dermatoses with extremely variable clinical manifestations is commonly present as well defined erythematous scaly plaques which become silvery on an attempt to scrap. Various types of psoriasis include plaque or vulgaris, guttate, pustular, erythrodermic, flexural, palmo-plantar, arthritis and nails psoriasis [1]. Prevalence of psoriasis varies from 0.12-8% all over world population [2]. It is more in cold climate. It affects equally to male and female. It is seen in all age group; however when it occurs in early age group its association with HLA B57 and B13 is more. Remission and relapses are very common in psoriasis. Various therapies used include topically coaltar [3], diathranol, corticosteroids with or without salicylic acid, calcipotriol [4], tazarotene and PUVA. Systemic therapies include [5] methotrexate [6,7], methotrexate +betamethasone [8], cyclosporine [9], PUVA, narrow band UVB, photo-therapy [10], hydroxyurea [11], azathioprine, retinoid like etretinate and acitretin [12-14] and biologics like etanercept and infliximabs [15]. All these treatment clear the psoriasis lesions partially or completely but are not able to prevent relapse or produce prolonged remission. Maximum remission period reported with these therapies is 1 year [16]. The chief problem in the management of psoriasis with various types of therapies is frequent relapses and subsequent need for repeated doses of systemic therapy leading to serious side effects. Repeated use of topical application usually leads to noncompliance by the patients. The goal of psoriasis treatment should be to control the disease process initially; to decrease percentage of involved body surface area, to achieve and maintain remission for prolonged period or permanently, to produce minimum adverse side effects and to improve patient’s quality of life. Thus the need for more specific systemic therapy which targets the T lymphocyte with the promise of long term remission and less organ toxicities is needed. Precipitating factor in psoriasis Trauma in the form of burn, cut and scratch may produce and localized the lesions (Koebner’s phenomenon). Usually winter aggravates and summer improves the disease. Infections: Bacterial infection especially streptococcal infection of upper respiratory tract, otitis media in children and infection in perianal area is associated with guttate psoriasis. Drugs: Like chloroquine, beta-blocker and lithium are presumed Correspondence to: Dr. Ramji Gupta, 47-C Pocket B Siddhartha Extension, New Delhi-110014, India, Tel: 91-11-26347405; E-mail: drramjigupta@yahoo.co.in