Psoriasis

Bhushan Kumar

 Former Prof. and Head, Department of Dermatology, Venereology and Leprology, PGIMER, Chandigarh, India

Correspondence Address:
Bhushan Kumar
H. No. 81, Sector 16, Chandigarh
India

This issue of the Indian Journal of Dermatology Venereology and Leprology has a special symposium section on psoriasis of particular relevance to the practicing dermatologist.

Any discussion or a symposium on a chronic, recalcitrant disease like psoriasis, which has a large psychosocial and management component affecting every part of the life of a patient, is always a welcome relief which brings in some hope, though short lived.

Wide variations in the presentation of the disease even in the same individual with every recurrence or relapse defy any logic or understanding of the precise etiology. Similarly, incidence and clinical presentation of the disease has varied widely. Though the role of T-cells is widely accepted, it again has a rider that this mechanism operates in genetically susceptible individuals with environmental and antigenic stimuli acting as co-factors. Hardly any humoral, hormonal or bio-chemical abnormalities occur - not counting isolated reports of some abnormalities in metabolism. Clear understanding of the cause and effect relationship is essential to be pragmatic.

The main area of concern, both for the dermatologists and the patient, had been the therapeutic options available. Indeed there are plenty of them - based on limited trials - for a limited period of time and based on every possible assumption including immune dysregulation, inflammatory cascade and consequent recruitment of polymorphs, the control of response to antigenic stimulation, proliferation of new capillaries and reduction of the rapid epidermal turnover by slowing down mitosis. Almost every modality has been reported to be effective in small prospective studies, mostly in plaque psoriasis - leaving out pustular, palmoplantar, erythrodermic, nail psoriasis and psoriatic arthritis. Unfortunately, most have not been reproduced or found to be uniformly effective.

Most of the systemic therapies - methotrexate, hydroxyurea, cyclosporine, retinoids (not found to be universally effective), systemic steroids (for specific situations) - have been useful for controlling extensive, wide spread diseases but have had no effect on the period of remission. Biologicals (new ones are appearing in the market at regular intervals) are the new addition in the same category of crisis management with hardly any effect on the long-term prognosis. Their effects have been varied, from being minimally effective to dramatic, but safety and close observations required are even more bothersome than the exorbitant cost.

Safe and affordable treatment options which still keep their promise are coal tar based preparations, dithranol (various drug delivery systems are likely to improve its efficacy and safety), topical steroids (used judiciously) and various fractions of UV rays (supported by the observations of seasonal variations in majority of the patients), UVA, UVB, UVA + UVB or narrow band UBV. These modalities have been used in various combinations with or without psoralens.

Children with psoriasis form a very special group because of their age, adjustment of dosage of systemic therapies and their long-term effects and the way they grow up through this psychologically crippling, unremitting disease.

The interesting and very up-to-date articles published in the symposium issue will definitely improve our existing knowledge about the understanding of the disease and help in making informed choice of the available modalities of treatment as the situation requires.

The majority of the articles are on epidemiology, new biologicals, therapeutic options in difficult to treat palmoplantar and scalp lesions, psoriatic arthritis, efficacy and safety of narrow band UVB. Another important and new area covered is on the drug delivery system - various technologies ensuring targeted delivery and so requiring a lower concentration of the drug with reduced side effects. Most of the contributors are from a premier dermatology center in north India with Dogra (as main or co-author), being the most prominent.

Prof. Thappa, chief editor, and his team deserve all the appreciation for choosing such an important disease for a more detailed discussion, one that not only affects the quality of life of the patient but also makes the dermatologist feel helpless and even ignorant about the designs and intricacies of Mother Nature. The effort continues to unravel her secrets.