Narrowband UVB Versus Narrowband P-UVB in cases of Chronic Plaque type Psoriasis: A Matched pair study

Karthika, Natarajan (2010) Narrowband UVB Versus Narrowband P-UVB in cases of Chronic Plaque type Psoriasis: A Matched pair study. Masters thesis, PSG Institute of Medical Sciences and Research, Coimbatore.


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INTRODUCTION : Psoriasis is a chronic inflammatory skin condition of unknown aetiology which affects approximately 1-3% of the worlds population. Clinically psoriasis manifests as erythematous plaques covered with silvery scales. It is characterized by hyperproliferation and abnormal differentiation of epidermal kertinocytes, lymphocyte infiltration consisting mostly of T lymphocytes and various endothelial vascular changes in the dermis such as angiogenesis,dilation and high endothelial venule formation. Both genetic and environmental factors contribute to aetiology. Psoriasis is usually a life long disease with varying periods of remissions and exacerbations. The therapeutic options are wide ranging from topical to systemic agents and phototherapy. The goals of therapy should be to gain initial and rapid control of the disease process, achieve a longer duration of remission, provide a better quality of life by reducing the severity and minimizing the side effects. Phototherapy is the use of non- ionising radiation as a treatment modality. In the past three decades, phototherapy has greatly influenced treatment concepts in dermatology. Photochemotherapy (PUVA) consists of absorption of nonionizing radiation by an exogenous molecule. This substance is usually psoralen that is derived from the plant source ammi majus, psoralea corylofolia. UV radiation has been used in the management of skin diseases such as psoriasis and atopic dermatitis. The prototypic skin disease showing a favourable response to UVB phototherapy is psoriasis. UVB Phototherapy are now belived to act by immunomodulatory effects on human skin and suppression of accelerated DNA synthesis in psoriatic epidermal cells and this is important for of UV phototherapy. Narrow-band UVB (NbUVB; 311-313nm) has proved as effective as PUVA with minimal long term side effects such as carcinogenicity. Since photochemotherapy entails the use of psoralen. It is associated with more side effects and cannot be administered to children. However, Narrow – band UVB is effective without the use of psoralen and so is gradually replacing photochemotherapy. There are certain cases which do not respond adequately to both PUVA and NbUVB. This study is undertaken to determine whether addition of psoralen makes Nb UVB more effective than NbUVB without psoralen. AIMS AND OBJECTIVES : To compare Narrowband UVB and Narrowband P-UVB in treatment of Chronic plaque type Psoriasis. Materials and Methods Seventeen patients of chronic plaque type psoriasis were enrolled in our study. A Baseline Total lesional severity scale (TLSS)to assess erythema, scaling and thickness were calculated and minimal erythema dose (MED) was determined for all the patients. MED was determined by standard method. A template with 10 apertures of 1½ x 1½ cm2 were made over the back of a cotton suit. Cotton flaps were made over the apertures enabling us to either shut or keep the apertures open by using Velcro. The source of Narrow-bandUVB was the whole body phototherapy unit with 24 Philips TL -01 bulbs(V Care medicals services Pvt Ltd). To determine MED a single panel in the whole body unit with 6 bulbs were used. All the apertures were kept opened and the back was irradiated with 250mj of Narrow-band-UVB. The first aperture was closed and the remaining apertures were then closed one after the other after delivering 50mj more than the previous aperture. The dosage schedule for Narrow-band- UVB were 250mj, 300mj, 350mj, 400mj, 450mj, 500mj, 550mj, 600mj, 650mj and700mj. The readings were taken 24hrs after exposure. The dose at which the minimal perciptible erythema found was considered as MED. For every patient, two clinically characteristic lesions for assessment were selected on either side of the body. Narrow-bandUVB was given on right half of the body and the left half of the body was covered using a suite which covered one half of the body. Oral psoralen at a dose of 0.5mg/kg body weight was administered immediately to the patient and two hours later patients were exposed to narrowband UVB on the left half of the body while the right half was covered using the same suite. The initial dose of starting the treatment was taken as 70% of MED. The dose was gradually increased at the rate of 10% increment of the previous dose. The treatment was then given thrice weekly over a period of five weeks thereby completing a total of 15 sittings and the TLSS scoring was determined at the end of 5th, 10th, and 15th sittings respectively. Inclusion criteria: Chronic plaque type psoriasis, patients not on other modalities of treatment with minimum three weeks of wash off period and body involvement more than 20%. Exclusion criteria: Unstable psoriasis, erythrodermic psoriasis, pustular psoriasis, pregnancy, lactation, children under 12 years and body involvement <20% body surface area. Statistical analysis: For each patient an average score of erythema , scaling and thickness were calculated for NbUVB as well as NbPUVB at the end of 5,10 and 15 sessions. These values were compared using WILCOXON TEST. P value < 0.05 was considered as statistically significant. RESULTS : A total of seventeen patients were studied. The age range of the patients were between 31 years to 70 years with the mean age of 49 years. Of the seventeen patients, 15 were men and 2 were women. The duration of psoriasis varied between 2 years to 28 years with mean duration of 15 years. All these patients belonged to skin type IV / V. The Minimal Erythema dose varied between 250mj to 950mj with mean of 457mj. (Table I). Of the seventeen patients, thirteen completed the study, one patient was lost for follow-up ,three patients [2 patients by the end of 4th treatment and 1 patient by the end of 8th treatment] could not continue due to aggravation of psoriasis. The score of the patients who aggravated (Table III). The severity of the index lesion according to TLSS scoring before treatment and after five, ten and fifteen treatments were recorded as shown in table-I. The values when compared using Wilcoxon test (p value < 0.05) was considered as statistically significant. The statistical analysis Table II). The total TLSS score of fourteen completed patients at the end of five sittings is 132 (mean - 9.42) for NbUVB and 127(mean 9.07) for NbPUVB. The difference was not statistically significant. At the end of ten treatments the mean value was 5.76 for NbUVB and 4.92 for NbPUVB. There was statistical significance at this point [p value = 0.006]. However by the end of our study, after fifteen treatments the mean value for NbUVB and Nb-PUVB were 3.0 and 2.76 respectively which were statistically not significant. Minimal side effects like erythema, pigmentation and pruritus were encountered during treatment as shown in Table IV. CONCLUSION : We conclude that addition of psoralen does not increase the efficacy of Narrow Band UVB.

Item Type: Thesis (Masters)
Uncontrolled Keywords: Narrowband UVB ; Narrowband P-UVB ; Chronic Plaque type Psoriasis ; Matched pair study.
Subjects: MEDICAL > Dermatology Venereology and Leprosy
Depositing User: Subramani R
Date Deposited: 02 Mar 2018 16:31
Last Modified: 03 Mar 2018 06:20

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