Comparative study of PUVA Therapy Versus Narrow Band UVB Therapy in the treatment of Vitiligo

Field: Medicine (Health Sciences)

INTRODUCTION :
Vitiligo is an ‘idiopathic’ acquired depigmenting disorder
characterized by the loss of functional melanocytes from the epidermis. It is
the most common pigmentary disorder and it involves complex interaction of
environmental and genetic factors that ultimately contribute to melanocytes
destruction, resulting in the characteristic depigmented lesions.
Vitiligo can be extremely disfiguring, leading to significant patient
morbidity. Low self esteem, poor body image and poor quality of life has
been found in patients with vitiligo, including significant psychiatric
morbidity. This is of particular concern for children and adolescents, as they
are in their formative years and developing their sense of self.
Vitiligo is perhaps the most frequent depigmenting disorder,
occurring with a prevalence varying across populations, apparently being
less frequent in Caucasians (0.38%), African (0.34%), and Chinese[6]
(0.0093%) than in Indians (0.46–1.13%). Not so commonly, higher
prevalence may appear among isolated populations. Its pathogenesis has
been associated with genetic predisposition, autoimmune phenomenon and
neural and growth factor dysregulation as well as inherent cellular metabolic
defects leading to melanocyte apoptosis.
The phenotypical expression of vitiligo is polymorphic, and several
types of vitiligo are distinguished on clinical presentation. The natural course
of vitiligo is gradual, unpredictable and difficult to control. However,
sometimes the disease persists in a stable status for a long time. Vitiligo possess a treatment challenge and will remain so until we find treatments that give consistent, and long-term cure by repigmentation.
Several treatment modalities have been advocated including topical therapy
with potent topical corticosteroids, calcipotriol, tacrolimus, pseudocatalase
therapy and other modalities like melanocyte transplantation, skin grafting,
cosmetic camouflage or self tanning preparations and psychological therapy.
But these are often unsatisfactory for generalised Vitiligo, for which NB
UVB and PUVA are the most important therapies.
In 1974, Parish successfully introduced a treatment combining 8-
methoxypsoralen and UVA called PUVA using newly developed Henselar
high intensity artificial UVA light. The combination treatment of Psoralen
with ultraviolet A (PUVA) therapy is a standardised therapy for vitiligo and
is still the mainstay for non segmental vitiligo. Interestingly two-thirds of
patients receiving psoralens and ultraviolet light found the treatment
worthwhile, meaning that even if treatments are only partially effective, they
may achieve psychosocial relief.
The clinical studies with NBUVB in vitiligo are few. Earlier reported
studies were mostly done in the western population and the studies in the
darker race, including Indians, is limited. Narrow-band ultraviolet B
(NBUVB) is an emerging, effective and safe therapy for vitiligo. It is as
effective as PUVA without many side effects. In 1997, Westerhof and
Nieuweboer-Krobotova were the first to study the effect of NBUVB in
vitiligo. NBUVB therapy has also been reported to be safe in childhood
Vitiligo.
Recent reports have shown that NBUVB can induce significant
repigmentation in either generalized or segmental vitiligo. It inhibits the
induction and secretion of cytokines, and stimulates inactive melanocytes in
the outer root sheath of hair follicles to proliferate and migrate into vitiligo
lesions. In comparing the treatment of vitiligo with NBUVB radiation
versus topical PUVA, Westerhof concluded that UVB therapy was slightly
more effective, produced faster repigmentation and had fewer side-effects.
However, narrowband UVB therapy is not readily available and implies
significant start-up expenses.
There are only few studies to compare the safety and efficacy of
NBUVB therapy & PUVA therapy in the treatment of vitiligo. More number
of studies to compare the same is required. Hence this prospective study is
conducted.
AIMS OF THE STUDY :
To compare the efficacy and safety of PUVA therapy and NBUVB
therapy in the treatment of Vitiligo vulgaris in terms of
• Time taken for initial repigmentation.
• Mean grade of treatment response.
• Colour match.
• Psychological satisfaction.
• Side effects.
MATERIALS AND METHODS :
This randomised open prospective clinical study was conducted on forty Vitiligo vulgaris patients who attended outpatient clinic of Dermatology department at Tirunelveli medical college hospital, Tirunelveli over the period of 15 months from April 2009 to June 2010. Approval was
obtained from the institutional ethical committee prior to the conduct of this study.
PATIENT SELECTION :
Inclusion criteria:
a. Age 18 to 65 years.
b. Body surface area involvement greater than 10%.
c. Stable Vitiligo (Stable for more than one year).
Exclusion criteria:
a. Age less than18 years and more than 65 years.
b. Body surface area involvement lesser than 10%.
c. H/o Photosensitivity and Photo mediated disorders.
d. H/o administration of drugs causing photosensitization.
e. H/o skin malignancy, renal and hepatic diseases.
f. Pregnancy and Lactation.
g. Active Vitiligo.
h. Patient on any treatment for Vitiligo within previous 6 months.
The name, age, sex, address, outpatient number were noted. Following detailed clinical history was taken.
1. Time of onset of Vitiligo.
2. Course of the disease-stability and rate of progression.
3. Potential precipitating events including emotional stress and cutaneous Trauma.
4. History of photosensitivity and drug causing photosensitivity.
5. History of any treatment(Systemic, topical).
6. Any history of suggestive of Diabetes Mellitus, Hypertension, Thyroid disease, Anaemia and other autoimmune diseases.
7. Family history of Vitiligo.
8. History of any psychological impact by the Vitiligo.
All patients were examined under good light. Detailed dermatological examination including size, shape, number, color and distribution of lesions was done. Pattern of Vitiligo and mucosal involvements were taken into
account. Presence of leucotrichia in the patch was also noted.
Estimation of percentage of body surface area with Vitiligo was carried out by using rule of 9 (Wallace), 9% for head and neck (head 7%, neck 2%), 9% for each upper limb (arm 4%, forearm 3% hand 2%) 9% for the front of each lower limb (Thigh 5%, leg 2.5%, foot1.5 %) and 9% for the back of each lower limb (Thigh 5%, leg 2.5%, foot1.5 %). 9% for the front
of chest, 9% for the front of the abdomen, 9% for the upper back, 9% for the lower back and 1% for the external genitalia.
Palm size is taken as about 1% of body surface area for measuring small area of involvement. Any skin lesions suggestive of autoimmune disorders like Autoimmune thyroiditis, Diabetes mellitus, pernicious
anaemia, Addison’s disease if present were noted.
Laboratory investigations like routine blood examination (Hb, TC, DC & ESR), urine analysis, blood sugar, blood urea and serum creatinine, liver function tests, thyroid function test were done. ophthalmic examination was done to rule out cataract and retinal pathology Initial photographs were taken using canon digital camera before commencement of treatment, completion of every sixteen treatment sessions and at the end of the treatment.
Patients were randomly allocated to receive either PUVA or narrow band UVB by means of a sequentially numbered list
Treatment schedule, precaution to be taken during and after treatment, expected response, total duration of treatment and common side effects were explained to the patient. Informed consent was obtained from the patients before starting treatment.
CONCLUSION :
The NBUVB groups showed better response in all the treatment
response parameter compared. There was a statistically significant improvement seen in mean grade of treatment response at the end of treatment and the colour match. In the treatment of vitiligo NBUVB therapy is superior to PUVA therapy. However studies with larger group of patient
and longer duration of treatment and follow up are essential to reveal further differences or to confirm the result of this study.