Fitzpatrick’s Bio Skin Device

Bioskin device is a generator of UV-B radiation composed of three
main components:

1. UV-B short arc mercury lamp (100 Watt) which generates UV-B
with a spectrum of 280 to 320 nm with a maximum emission peak
at 311 nm;
2. Specialized liquid component optical fiber which can transmit
and focalize the emitted UV-B in a circular beam 1 cm in diameter.
3. Computerized system which allows the regulation of the
intensity (10-100 mJ/cm^2 /s) and time of single spot emission
(0.1-10 seconds).

/Light spot./

Each single spot produces an energy of 10-100 mJ/cm^2 on a 1 cm
diameter circular area (0.785 cm^2 ) for the time necessary to reach
the optimal dose. The optical fiber terminal is in contact with a
different site of the treated patch during the emission of each
spot. Repetition of single spots make it possible to treat VP areas
completely while avoiding normal skin. Complete treatment of a 10
cm^2 diameter vitiligous area with 100 mJ requires repeating a 2
second 1 cm^2 diameter spot 6 times with 100 mJ/cm^2 intensity.

/Treatment session/

Each treatment session consists of irradiation of the VP with a dose
20% lower than minimal erythema dose (MED) calculated by the
operator before the session. The length of each session depends on
the length of the single light spot and the extension of the VP areas.

/Treatment./

The MED in VP is evaluated 24 hours before the beginning of therapy.
The subjects are treated with the following scheme:

* 5 sessions, one a day for 5 consecutive days.
* 10 days break.
* 1 session every 15 days for 5 months.

The control subjects were treated with the same protocol but with
the UVB generator off. It was impossible for the control subjects to
know if the generator was on or not.

Table 3 shows the MED for each patient, dose per session for cm^2 ,
total dose given each subject per cm^2 and the final results.