Clinical and Spectrophotometric Evaluation of Skin Photoadaptation in Vitiligo Patients after a Short Cycle of NB-UVB Phototherapy.
Narrow-band ultraviolet B phototherapy
Photoadaptation
Spectrophotometry
Vitiligo
Journal
Dermatology (Basel, Switzerland)
ISSN: 1421-9832
Titre abrégé: Dermatology
Pays: Switzerland
ID NLM: 9203244
Informations de publication
Date de publication:
2019
2019
Historique:
received:
07
11
2018
accepted:
07
08
2019
pubmed:
7
10
2019
medline:
16
4
2020
entrez:
7
10
2019
Statut:
ppublish
Résumé
The phenomenon of photoadaptation to narrow-band ultraviolet B (NB-UVB) radiation has been previously described in vitiligo and has usually been clinically measured by the assessment of the minimal erythema dose (MED) after phototesting. To assess the photoadaptive response in vitiligo and healthy skin after NB-UVB phototherapy not only clinically, but also by spectrophotometry. Fourteen patients affected by generalized vitiligo underwent NB-UVB phototherapy twice weekly for 12 weeks. Before and after phototherapy, a phototesting procedure was administered on vitiligo patches and adjacent healthy skin with a solar simulated radiation (SSR). Visual assessment of the MED took place after 24 h. A spectrophotometer was used to assess the a* value and the melanin index (MI*), as signs of skin erythema and pigmentation. The photoadaptation factor (MED-PF) and the a* photoadaptation factor (a*-PF) were calculated. After NB-UVB phototherapy, both vitiligo and healthy skin showed an increase in MED and MI* values and a reduction of skin erythema compared to baseline (p < 0.05). MED-PF data showed a photoadaptation in 10 (71.4%) vitiligo lesions and in 12 (85.7%) healthy skin areas. The assessment of the a*-PF showed a negative mean percentage value in all affected and unaffected skin areas. A short cycle of NB-UVB phototherapy can induce photoadaptation in vitiligo by increasing the MED and reducing skin erythema after stimulation with SSR. This is most likely due to the physical filter function induced by ultraviolet radiation.
Sections du résumé
BACKGROUND
BACKGROUND
The phenomenon of photoadaptation to narrow-band ultraviolet B (NB-UVB) radiation has been previously described in vitiligo and has usually been clinically measured by the assessment of the minimal erythema dose (MED) after phototesting.
OBJECTIVES
OBJECTIVE
To assess the photoadaptive response in vitiligo and healthy skin after NB-UVB phototherapy not only clinically, but also by spectrophotometry.
MATERIALS AND METHODS
METHODS
Fourteen patients affected by generalized vitiligo underwent NB-UVB phototherapy twice weekly for 12 weeks. Before and after phototherapy, a phototesting procedure was administered on vitiligo patches and adjacent healthy skin with a solar simulated radiation (SSR). Visual assessment of the MED took place after 24 h. A spectrophotometer was used to assess the a* value and the melanin index (MI*), as signs of skin erythema and pigmentation. The photoadaptation factor (MED-PF) and the a* photoadaptation factor (a*-PF) were calculated.
RESULTS
RESULTS
After NB-UVB phototherapy, both vitiligo and healthy skin showed an increase in MED and MI* values and a reduction of skin erythema compared to baseline (p < 0.05). MED-PF data showed a photoadaptation in 10 (71.4%) vitiligo lesions and in 12 (85.7%) healthy skin areas. The assessment of the a*-PF showed a negative mean percentage value in all affected and unaffected skin areas.
CONCLUSIONS
CONCLUSIONS
A short cycle of NB-UVB phototherapy can induce photoadaptation in vitiligo by increasing the MED and reducing skin erythema after stimulation with SSR. This is most likely due to the physical filter function induced by ultraviolet radiation.
Identifiants
pubmed: 31586997
pii: 000502853
doi: 10.1159/000502853
doi:
Types de publication
Journal Article
Langues
eng
Sous-ensembles de citation
IM
Pagination
509-515Informations de copyright
© 2019 S. Karger AG, Basel.