Phototherapy in atopic dermatitis

Patients with atopic dermatitis frequently observe an improvement in their symptoms during summer due to the increased sun exposure. During the course of the summer holidays, 74% of patients with mild-to-moderate atopic dermatitis saw complete resolution in one study. Interestingly, more patients saw complete resolution on seaside holidays (91%) than mountain holidays (11%) (Patrizi et al, 2009). While UV exposure does not completely explain this difference, it supports the positive effects of UV radiation on atopic dermatitis (Wollenberg et al., 2018).

Table 8: Phototherapy options (Wollenberg et al, 2018).

Phototherapy options (Wollenberg et al, 2018).


In Europe, NB-UVB has been used for patients with chronic, moderate forms of atopic dermatitis and is preferred to BB-UVB, while more severe cases have been treated with UVA1 (Wollenberg et al., 2018). Interestingly, a small number of patients with atopic dermatitis do not tolerate NB-UVB but respond well to BB-UVB (Pugashetti et al., 2010).

Mechanism of action

Ultraviolet radiation has been observed to produce a number of biological effects within the skin that may explain its ability to treat atopic dermatitis.

Proposed mechanisms of action for phototherapy in atopic dermatitis.

Figure 20: Proposed mechanisms of action for phototherapy in atopic dermatitis (Wollenberg et al., 2018).