Targeted phototherapy

What it is

Phototherapy means delivering light or ultraviolet radiation to treat skin disorders. Targeted phototherapy — also called concentrated phototherapy, focused phototherapy or micro phototherapy — delivers the ultraviolet radiation directly onto the skin lesion through a special delivery mechanism. The term covers both laser and non-laser technologies. Most devices emit radiation in the UVB range, with peak emission in the narrowband wavelength around 308–311 nm, while some non-laser machines emit UVA as well.

What it treats

Vitiligo, in localised and resistant patches; localised plaques of psoriasis; hypertrophic lichen planus; cutaneous T-cell lymphoma (mycosis fungoides); morphoea; and hand eczema.

How it works

Most of these machines use a conventional high-pressure burner emitting ultraviolet light. Fibre-optic cable systems deliver the energy directly to the lesion. Some machines can supply both UVA (330–380 nm) and narrowband UVB (290–330 nm), and can deliver preset doses, so treatment time is short.

Why it is used

• Only the involved areas are exposed, sparing uninvolved skin.
• Energy is delivered quickly, so each session is shorter.
• Because uninvolved areas are not exposed, higher doses of energy can be delivered selectively to the lesions.
• Shorter treatment means fewer visits to the clinic and less inconvenience.
• The manoeuvrable hand piece allows treatment of difficult areas such as the scalp, nose, genitals, lining of the mouth and ear.
• It is easy to administer to children, because delivery is hand-held.
• The machines occupy less space.

Limitations

Targeted phototherapy is more expensive. It is not adequate for treating extensive areas, given the cost and the time involved, and it is not recommended when lesions cover more than about 10 per cent of the body area.