Narrowband ultraviolet B minimal erythema dose reference range

Area of Science:

• Dermatology
• Photobiology
• Clinical Research

Background:

• Narrowband ultraviolet-B (NB-UVB) phototherapy is a standard treatment for skin conditions.
• Minimal erythema dose (MED) testing is crucial for determining optimal NB-UVB dosage and identifying photosensitivity.
• Variability in MED values can impact treatment efficacy and safety.

Purpose of the Study:

• To analyze and compare Minimal Erythema Dose (MED) values from two distinct patient cohorts undergoing narrowband ultraviolet-B (NB-UVB) phototherapy.
• To investigate the relationship between MED values and Fitzpatrick Skin Phototype (SPT).
• To establish updated reference ranges for NB-UVB MED testing and inform clinical practice.

Main Methods:

• Retrospective analysis of MED values from 882 patients in Dundee and 188 in London.
• Exclusion of patients with abnormal photosensitivity or repeat MED tests.
• Statistical comparison of MED values across different Fitzpatrick Skin Phototypes (SPT) and between the two study centers.

Main Results:

• Median MED values generally increased with higher Fitzpatrick Skin Phototypes (SPT), but significant overlap was observed.
• Dundee cohort showed statistically lower MED values compared to the London cohort for SPT II/III.
• Lower MEDs were reported compared to previous volunteer studies, with higher non-responder rates in SPT IV-VI.

Conclusions:

• Existing MED values for NB-UVB phototherapy exhibit inter-center variability and require updated reference ranges.
• Current testing protocols may need adjustment, particularly for individuals with darker skin types (SPT IV-VI), to address higher non-responder rates.
• These findings support refining NB-UVB phototherapy protocols for improved patient outcomes.