PUVA in eczema

Psoralen-ultraviolet A (PUVA) in eczema:

• UV radiation has profound effects on skin and systemic immune responses. Both narrow-band UVB and PUVA (psoralen + UVA) therapies are used for atopic eczema
• psoralens work by photosensitising the skin
  • there are possible short-term and long-term side effects to phototherapy:
    • UVB light can cause burning; PUVA increases the incidence of skin cancers (1) - this is a dose-related effect relating to the total amount of PUVA received
    • narrow-band UVB is thought to be safer and therefore can be used in children
    • psoralen tablets can cause nausea; also the photosensitisation requires sunglasses to be wore for a period of time after treatments to help prevent formation of cataracts
    • is a type of ultraviolet radiation treatment that starts with a photosensitising medicine, called a psoralen, and is followed by exposure of the aIected skin to ultraviolet A (UVA)
• for oral PUVA, oral psoralens (e.g. 8- methoxypsoralen, 5-methoxypsoralen) are taken two to three hours before exposure to UVA in a phototherapy cabinet
• often used as a second-line option for treating eczema that has failed to respond to topical corticosteroids and calcineurin inhibitors
• narrowband ultraviolet B (UVB) phototherapy is preferred over broadband UV phototherapy, including PUVA
  • the latter is associated with increased risk of non-melanoma skin cancer, despite its eIectiveness with refractory eczema
• typically, twice-weekly PUVA treatments are given for eczema, and the dose of UVA radiation is gradually increased over the course of treatment.
  long-term continuous treatment is not advised due to increased risk of developing skin cancers
• can be used as a monotherapy or in combination with emollients and topical corticosteroids
• topical calcineurin inhibitors should be avoided on days of PUVA treatment, as these are photosensitising and could increase the risk of burning. Other oral or topical photosensitising treatments (e.g. tetracyclines) should be avoided during PUVA treatment

Reference:

1. Prescriber (2001); 12(12).
2. NICE (December 2007).Atopic eczema in children Management of atopic eczema in children from birth up to the age of 12 years.
3. Sawangjit R et al. Systemic treatments for eczema: a network meta-analysis. Cochrane Database of Systematic Reviews 2020, Issue 9. Art. No.: CD013206. DOI:10.1002/14651858.CD013206.pub2