Population reference intervals for minimal erythemal doses in monochromator phototesting

Area of Science:

• Dermatology
• Photobiology

Background:

• Monochromator phototesting measures the minimal erythemal dose (MED) to assess abnormal photosensitivity.
• Reliable, current MED data in normal individuals is crucial for accurate phototesting.

Purpose of the Study:

• Determine MED in normal subjects across different ultraviolet (UV) wavebands.
• Compare current MED values with historical control data.

Main Methods:

• Phototesting of 415 normal individuals (skin types I-III) in Scotland using a monochromator.
• Testing wavelengths ranged from 295 nm to 430 nm.
• Calibrations were traceable to the National Physical Laboratory, with quality systems adhering to ISO 9001 and ISO 17025 standards.

Main Results:

• The 95% reference interval for MED varied significantly with wavelength.
• MED ranged from 6.8 to 27 mJ/cm(2) at 295 nm.
• MED exceeded 82,000 mJ/cm(2) at 430 nm.

Conclusions:

• Current MED findings align with data published 25 years prior by the same center.
• This consistency validates the monochromator phototesting process.
• Careful control of UV exposure conditions and MED reading, supported by dosimetric calibration, ensures reliable results.