Psoriasis Case 2: Ultraviolet B (UVB)

A 51-year-old postmenopausal woman with a 25-year history of psoriasis presented for evaluation of worsening disease. She had been treated in the past with multiple topical medications with only partial control. Two years before presentation, she was given the diagnosis of multiple sclerosis and is currently well controlled with glatiramer acetate. Like many psoriatics with significant disease, she imbibes excess alcohol (12-18 beers each weekend). There is no history of arthritis, diabetes, or hypertension. 

Cutaneous examination reveals 15% BSA involvement with erythematous patches and plaques with silvery scales on the trunk, and upper and lower extremities. Mildly erythematous patches with fine scales are noted on the face, with thick plaques covered by micaceous scales evident on the scalp. Mild palmar and plantar involvement is also observed.

Discussion

In view of the significant BSA involvement, history of worsening of psoriasis, along with the history of alcohol excess and multiple sclerosis, narrowband (NB)-UVB is an attractive treatment option, while recognizing its limitations in improving scalp psoriasis, a significant problem in our patient. NB-UVB is well tolerated, cost effective, and can be used safely in patients with demyelinating disease, in which the use of TNF-alfa-inhibiting biologic agents is contraindicated.

Although also being appropriate for patients with large BSA involvement,54 NB-UVB can be administered in an outpatient setting or in a day hospital. In darker-skinned individuals and in patients with very thick lesions, PUVA photochemotherapy is likely to be more efficacious because of the better penetration of UVA compared with UVB.54 NB-UVB has many advantages over PUVA, including a lower long-term photocarcinogenic risk, the lack of need for oral medication before each treatment session or photoprotective eyewear between treatments, and safety in pregnancy.54 Remission duration with NB-UVB is, however, shorter than with PUVA. A limiting factor of UV-based therapy is the need for 2 to 3 visits per week to a phototherapy center; once clearance has been achieved, home NB-UVB phototherapy for maintenance therapy is an attractive alternative.81 If the patient fails to obtain an adequate response after approximately 20 to 30 treatments with NB-UVB given 2 to 3 times weekly, PUVA, traditional systemic agents, or biologic agents should be considered. Because of the history of significant alcohol intake, MTX would be contraindicated in this patient.53

Acitretin is teratogenic and thus is contraindicated for use in treatment of psoriasis in women of childbearing potential. It could be considered as a reasonable option for this postmenopausal woman either as monotherapy or in combination with NB-UVB. With combination therapy lower doses of acitretin and fewer NB-UVB sessions are usually needed to obtain clearing. Fewer mucocutaneous side effects are seen with lower acitretin doses. Up to 16% of patients treated with acitretin develop elevated liver function tests (LFT) findings;53 therefore, patients need to be regularly monitored for LFT abnormalities. This is particularly true for patients such as ours with a history of excessive alcohol consumption. Acitretin therapy hastens the resolution of scaling and decreases the thickness of psoriatic plaques, hence improving the efficacy of NB-UVB and reducing the total number of phototherapy treatments82 needed. Acitretin may also be effective in palmoplantar psoriasis. Patients being treated with acitretin and UVB combination therapy should have their UVB exposure times increased cautiously, because epidermal thinning caused by acitretin therapy will make the patient’s skin more susceptible to UV-induced erythema. In patients who are already on phototherapy or photochemotherapy when acitretin is added, it is appropriate to decrease the UV dose by 20% to 30% before resuming the graduated increases in UV dose.

Navigate section 6 of the psoriasis guideline: Case-based review

Citation note

Menter A, Korman NJ, Elmets CA,Feldman SR, Gelfand JM, Gordon KB, Guidelines of care for the management of psoriasis and psoriatic arthritis: section 6. Guidelines of care for the treatment of psoriasis and psoriatic arthritis: case-based presentations and evidence-based conclusions. J Am Acad Dermatol. 2011 Jul;65(1):137-74. 



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