Should we switch from combination UVA/UVB phototherapy units to narrowband UVB?

With the dozens of treatments available for psoriasis, why do we need newer treatments that are more expensive and have not stood the test of time? The same question could have been asked 80 years ago when William Goeckerman introduced his regimen for the treatment of psoriasis. And the answer remains the same: We will always be looking for treatments that are more effective, safer and more convenient. The rush to narrowband UVB is justified because it has been driven by efficacy that is superior to that of broadband UVB and a safety profile that theoretically should be better than that of PUVA. The question that is often asked by dermatologists starting out or beginning to use phototherapy is whether they should purchase combination UVA/UVB units or narrowband phototherapy units. There are certain advantages to narrowband UVB. For many patients, it is clearly superior to broadband UVB. In a bilateral comparison study in which half the body was exposed to narrowband UVB and the other half to broadband UVB daily for 4 weeks, clearing of psoriasis was achieved in 86% of sides treated with narrowband UVB versus 73% treated with broadband UVB (1). In the typical plaque psoriasis patients studied, however, differences between the two treatments were not striking. In contrast, patients refractory to broadband UVB frequently respond to narrowband UVB. Narrowband is not only effective for psoriasis, it is also used for many disorders previously treatable only with PUVA. It has been used to successfully treat vitiligo (2), small plaque parapsoriasis (3) and mycosis fungoides (3, 4), and atopic dermatitis in children (5) and in adults (6). In a bilateral paired comparison study looking at bath PUVA versus narrowband UVB, both regimens were judged to be equally effective for severe, chronic atopic dermatitis when administered in comparably erythemogenic doses (7).Narrowband UVB has also been used to treat seborrheic dermatitis (8), dermatoses of pregnancy (9),subcorneal pustular dermatosis of Sneddon-Wilkinson (10, 11) and a number of photodermatoses (12), including