ABSTRACT
Psoralens are naturally occurring furocoumarins that are found in several plant species. They appear to have a protective role against microbes and inhibit germination of seeds. These aromatic molecules strongly absorb certain ultraviolet (UV) wavelengths and act as photosensitizers when administered orally or topically. Photochemical reactions involve the interaction of light or UV radiation with a specific molecule or chromophore, which absorbs this radiation to induce a photochemical reaction. Psoralen-UVA (PUVA) photochemotherapy achieves high rates of clearance and prolonged disease-free intervals, although the long-term course of the disease may be unchanged. Good-quality randomized control trials on the use of PUVA in the management of atopic eczema (atopic dermatitis) is limited. Oral psoralens should not be used routinely in children under the age of 10 years, due to long-term risk of carcinogenicity. Treatment can be undertaken in special circumstances with great caution.
