Narrow-band UVB (c) would be Dr. Gordon’s choice, although other answers are reasonable. A clearly wrong answer is (a) Targeted narrow-band UVB, which should not be used for extensive psoriasis.
He said that he would begin treating the patient with narrow-band UVB three times per week. Some published protocols suggest starting at 400 mJ/cm2, but based on her type II skin, he said he would start at 200 mJ/m2 and increase the dose by 25-mJ increments over time. "Why 200 mJ instead of 220 mJ? The math is easier. For the people who work with me, I want the math to be really easy," he said.
Applying petrolatum or mineral oil before phototherapy can eliminate the reflectiveness of the scale to help the light penetrate, but make sure the patient is willing to do this for every treatment. "If they don’t have it as you’re building up the dose, and then they start using it, that’s when people get burned," he explained. "You just have to be consistent."
Four to 6 weeks of thrice-weekly treatments should produce a good response. There’s a dearth of data to help clinicians decide what to do after that. Some reports suggest more patients will remain clear at 1 year if treatment is decreased to twice weekly for 4 weeks and then once weekly instead of stopping phototherapy. Ultimately, this may entail fewer phototherapy sessions than stopping phototherapy and having to resume thrice-weekly sessions if the psoriasis flares again.
"Maintenance therapy is a real way to make life easier for patients with phototherapy. I think it’s a very underused process," he said. Dr. Gordon does not decrease the dose when shifting to maintenance phototherapy, but others recommend decreasing the dose by 25% during once-weekly sessions.
Data on the safety of long-term narrow-band UVB in patients with psoriasis are insufficient, but European studies suggest it does not significantly increase the incidence of nonmelanoma skin cancer. "I leave it up to the patient" to decide if this is acceptable, he said.
– Case 3: Dr. Gordon chose (a) Narrow-band UVB with expectation for short-term treatment. Unlike chronic psoriasis, guttate psoriasis is basically a self-limited disease, so short-term phototherapy is more appropriate than chronic therapy or biologics. Patients tend to respond quickly to narrow-band UVB therapy. PUVA therapy also might be a reasonable treatment, but Dr. Gordon said he has not used it for guttate psoriasis.
"Later on in life, many of these patients will come back and have plaque psoriasis," and then other treatments may be appropriate, he noted.
– Case 4: There’s no clear answer for this case because of a lack of data, according to Dr. Gordon, but he would choose (d) Topical PUVA with a hand-foot UVA unit. "The decision rests on what you sense is best for the patient," but this method is most effective in his experience, he said.
His second choice would be targeted narrow-band UVB with excimer laser, which may be effective at higher fluences but carries the risk of hyperpigmentation. The hand-foot narrow-band UVB unit also is somewhat effective. With limited disease such as this palmar psoriasis, he tries to avoid use of oral psoralen, so would not choose oral PUVA with a hand-foot UVA unit.
– Case 5: For this patient, Dr. Gordon would choose (c) Retinoids plus narrow-band UVB. Erythrodermic psoriasis features inflamed, fine-scaled skin, which is distinct from extensive plaque psoriasis. The patient’s extensive disease needs a high rate of response, so Dr. Gordon would add a retinoid to the UVB to try to boost the treatment benefit.
He advised starting acitretin first for about 1 month to make sure the patient tolerates it and to see if the disease clears on the retinoid alone, without the need for phototherapy. The protocol for UVB should account for the addition of this photosensitizing agent. Dr. Gordon usually decreases the phototherapy dose by one skin type to account for the retinoid. Others suggest decreasing the dose by 25-50 mJ/cm2.
– Case 6: No one in the audience at the meeting picked the correct answer, (d) None of the above. Phototherapy often will worsen erythrodermic psoriasis in people with light skin. Avoid phototherapy in these patients. "If you put somebody like this in a light box, you’ll be in real trouble," he warned. This patient responded well to biologic therapy.
Dr. Gordon has been a consultant for or received grants from Abbott, Amgen, Centocor, Galderma, Lilly, Pfizer, Celgene, and Merck. Also, a partner in his practice derives income from phototherapy.