Assessment of the usefulness of skin phototype and skin color as the parameter of cutaneous narrow band UVB sensitivity in psoriasis patients.
ABSTRACT Many reports have been released to assess skin types, skin colors and cutaneous sensitivity to broad band UVB or UVA.
This study was performed to investigate the usefulness of skin type and skin color as the parameter of narrow band UVB (NBUVB) sensitivity.
The minimal erythema dose (MED) of 40 psoriasis patients was investigated by irradiating several doses ranging from 200 to 1500 mJ/cm2. Before phototesting, the skin color of buttock was measured with a tristimulus colorimeter.
The median and mode value of MED of NBUVB was 950 mJ/cm2. Skin type was well correlated with the MED and there was a significant relationship between the L* value and MED, but not for the a* and b* values.
The MED value of NBUVB in our study is a basic data to set the phototherapy protocol. Our result showed that skin type and L* value might be useful for predicting the sensitivity to NBUVB irradiation.
- SourceAvailable from: PubMed Central[Show abstract] [Hide abstract]
ABSTRACT: The spectrophotometer is well known to be a useful tool for estimating the objective minimal erythema dose (MED) during planning of phototherapy protocol. However, only a few spectrophotometric values are used to evaluate the erythema and pigmentation of the MED site during phototesting. To determinea new meaning of the relationships among spectrophotometric values during phototesting. Twenty-five patients with psoriasis and 23 patients with vitiligo were selected before undergoing narrowband ultraviolet B phototherapy. We interpreted the gross findings of erythema and measured the L(*)a(*)b(*) values using a spectrophotometer at each phototest spot. We compared MEDs, basic spectrophotometric values (L(*)a(*)b(*)), and b(*)/L(*) values separately according to skin type, and determined the correlation of each spectrophotometric value and the correlation between a(*) and b(*)/L(*) values. Among L(*)a(*)b(*) values, only b(*) values showed a statistically significant difference between the type III and IV groups (p=0.003). There was a positive correlation only between MEDs and b(*) values (p<0.05). The average b(*)/L(*)value in the type IV group was significantly higher than the type III group (p<0.05). The higher b(*) values in type IV skin indicates that skin tanning develops more prominently than type III. The correlation between MEDs and b(*) values may signify that the skin pigmentation status is deepened with the higher MEDs. The difference in b(*)/L(*)values between type III and IV skin reflects that the b(*)/L(*)value is thought to be an index of tanning. The a(*) value, known as an index of erythema, does not influence the degree of tanning.Annals of Dermatology 02/2014; 26(1):17-25. · 0.95 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: The aim of this study was to investigate the duration of remission periods in psoriasis after narrowband ultraviolet B (NB-UVB) phototherapy, especially during multiple cycles of treatment. We analyzed 63 patients (101 cases) demonstrating marked improvement after NB-UVB phototherapy. The remission period was defined as the duration of time from the end of phototherapy until treatment using either phototherapy or systemic treatments was required again. It was found that an age of 60 years or older, history of systemic therapy within 6 months and three or more phototherapy cycles were significantly associated with shorter remission periods. Furthermore, multivariate analysis confirmed that three or more phototherapy cycles (odds ratio [OR], 4.0; 95% confidence interval [CI], 1.73-9.33; P = 0.001) and a history of systemic therapy (OR, 2.2; 95% CI, 1.27-3.95; P = 0.005) were independently associated with the shorter remission period. In conclusion, when planning NB-UVB phototherapy for psoriatic patients who have undergone multiple phototherapy cycles, clinicians should consider the possibility of shorter remission periods.The Journal of Dermatology 06/2014; · 2.35 Impact Factor
Article: Minimal Erythema Dose (MED) Testing.[Show abstract] [Hide abstract]
ABSTRACT: Ultraviolet radiation (UV) therapy is sometimes used as a treatment for various common skin conditions, including psoriasis, acne, and eczema. The dosage of UV light is prescribed according to an individual's skin sensitivity. Thus, to establish the proper dosage of UV light to administer to a patient, the patient is sometimes screened to determine a minimal erythema dose (MED), which is the amount of UV radiation that will produce minimal erythema (sunburn or redness caused by engorgement of capillaries) of an individual's skin within a few hours following exposure. This article describes how to conduct minimal erythema dose (MED) testing. There is currently no easy way to determine an appropriate UV dose for clinical or research purposes without conducting formal MED testing, requiring observation hours after testing, or informal trial and error testing with the risks of under- or over-dosing. However, some alternative methods are discussed.Journal of Visualized Experiments 01/2013;