Low-dose UVA1 phototherapy is a feasible and effective treatment option for a broad range of treatment-resistant skin conditions including atopic dermatitis and sclerodermas, Queensland dermatologists say.
In a retrospective review of outcomes for 87 adult patients treated in a private dermatology practice, Dr Michael Pitney and colleagues report that 92% of the patients experienced beneficial results with a 12-week course of UVA1 phototherapy in conditions that had previously been unresponsive to other treatments.
The low dose UVA1 phototherapy was effective against conditions including mycosis fungoides, urticarial dermatitis, generalised pruritus, lichen sclerosis and granuloma annulare, he reports in an article in the Australasian Journal of Dermatology.
Dr Pitney says that the longer wavelength (340–400 nm) of UVA1 penetrates further into the dermis than shortwave UVA and UVB and induces unique immunosuppressive responses against T- and B-lymphocytes and other immune modulators such as TNF alpha and interleukins.
And unlike the expensive and cumbersome equipment used to deliver high dose high dose UVA1 phototherapy, patients could treated with a low intensity dosage of 30 joules/cm2 of UVA1 three times a week (30 minutes per session) delivered by a conventional phototherapy unit using UVA1-emitting fluorescent tubes.
The retrospective review found that more than half the patients (54%) had a complete response, with greater than 95% clinical clearing and reduction in pruritus in the case of inflammatory and infiltrative conditions, or evidence of marked softening of skin fibrosis, improved cutaneous elasticity, joint mobility and absence of active disease and pruritus, in fibrosing disorders.
A further 38% of patients were partial responders, achieving greater than 50% improvement in clinical markers, and 8% were non responders.
“Complete response rates were high in localised scleroderma, atopic dermatitis, mycosis fungoides and graft-versus-host disease,” Dr Pitney writes.
“Most other conditions showed a favourable response, with partial responders more likely to have had incomplete courses of therapy.”
Patients with chronic and relapsing conditions such as atopic dermatitis, aquagenic pruritus and mycosis fungoides continued to show good results with maintenance therapy once weekly or fortnightly.
Dr Pitney says the UVA1 phototherapy was generally well tolerated, although some patients had discomfort from heat-induced erythema and vasodilation, and tanning was to be expected. The long term effects on skin cancer are not clear, he added, and all patients have regular skin examinations, at least annually.
“These potential risks need to be balanced against risks of alternative treatments, which may involve long-term immunosuppression with less clinical efficacy,” he says.
“Ultraviolet A1 is an effective and safe treatment option in many hitherto recalcitrant cutaneous conditions,” the review concludes.