The following are types of light therapy:
Phototherapy
This is useful in cases of stubborn, chronic atopic dermatitis. UVB combined with emollients and tar have certainly been helpful. UVB is not suitable for acute exacerbations. It appears that a combination of UVA as well as UVB is better than UVB alone. PUVA (psoralens + UVA) appears more effective than UVB. There is the problem of rebound effect after discontinuing PUVA and the increased risk of skin cancer is documented.
Narrow Band UVB
311 nanometers has been useful although further work needs to be done. A report on 5 patients with severe atopic eczema shows efficacy in all patients with a cumulative dose of 9.2 J/cm2 Benefit was seen after 3 weeks.
J Am Acad Dermatol 1999;40:995-7
PUVA
This involves a combination of an oral photosensitizing drug psoralen combined with UVA. This has been shown to be effective in children resulting in clearance or near clearance.
Br J Dermatol 1988;118:791-5
Br J Dermatol 1993;129:431-6