Phototherapy 

Because UV light can suppress the immune system, phototherapy is used to decrease the inflammation associated with skin conditions responsive to this therapy.

Skin disorders that can be treated with phototherapy include the following:

• Psoriasis
• Eczema
• Vitiligo
• Itching
• Cutaneous T-cell lymphoma

Poor candidates for UV light and PUVA therapy include people who are pregnant or breast-feeding or with the following:

• Allergy to sunlight
• History of skin conditions that worsen with UV light exposure (eg, lupus, types of porphyria)
• History of skin cancers
• Exposure in the past to substances or procedures that would increase the risk of skin cancers (eg, arsenic or radiation therapy)
• Liver disease (for patients taking psoralen)
• Eye conditions that may be worsened by phototoxicity
• Inability to stand