In infants, psoriasis commonly involves the face and diaper area.
“That makes sense in because these are the sites subjected to Koebnerization from frequent wiping. For adults, the elbows and knees get the most frictional abuse,” Dr. Siegfried says.
Other areas of predilection in young children are the thumb (if they’re thumb-suckers) and scalp, often recognized as cradle cap in infants.
Besides the major trigger of low-grade skin trauma, psoriasis in children also can have a microbial trigger. The most recognized, according to Dr. Siegfried, is acute-onset, small plaque psoriasis associated with streptococcal (group A Strep) colonization or infection, called guttate psoriasis.
Dermatologists should consider using antibiotics to treat children with guttate psoriasis, who have confirmed evidence of streptococcus. In some cases, oral antibiotic treatment will result in a long-term remission. If children carry streptococcus, the psoriasis may quickly relapse after the antibiotics are discontinued. An option for carriers is to remove the tonsils, which reduces the microbial load and can result in at least temporary remission, Dr. Siegfried says.
First-line treatment of pediatric psoriasis is often a corticosteroid, but unlike eczema, topical monotherapy is less effective than combination treatment, and more often results in rebound after corticosteroid discontinuation.
“It is safest to limit long-term use of a topical corticosteroid to less than once daily, especially in young infants and children, because frequent application increases the risk of barrier weakening and percutaneous absorption,” she says.
A more effective treatment is a corticosteroid topical plus a corticosteroid-sparing agent, (topical calcineurin inhibitor or vitamin D analog). One option that combines medications is Taclonex (calcipotriene and betamethasone diproprionate, Leo) topical suspension for plaque psoriasis, which is the only FDA approved option for treating psoriasis in children, labelled for use on the scalp of adolescents, aged 12 to 17.
Dr. Siegfried frequently prescribes Taclonex. The ointment formulation is now available as a generic product, but even that is expensive. Insurance access is often restricted as off-label for children and when covered, even just the necessary copay is out of reach for many families, she says.
As patients get better on the combination, dermatologists should consider using a potent topical corticosteroid and vitamin D analog separately, to minimize the corticosteroid exposure.
For families who don’t have access to corticosteroid-sparing topical calcineurin inhibitors or vitamin D analogs, Dr. Siegfried says there’s the option of coal tar, although it has a strong odor and stains fabric, and there is concern about carcinogenicity.
The next line of treatment is phototherapy, which works well but is too difficult and time-consuming for most families.
“In-office phototherapy requires three-times-a-week visits for at least three to six months, and then twice a week, which is not practical for most busy families. There are other special challenges in delivering phototherapy to children. Some can’t resist removing their goggles to get a look at the bulbs, followed by retinal burns,” she says.
That brings dermatologists to systemic options for moderate to severe psoriasis. In November 2016, etanercept (Enbrel/ Amgen) was the first biologic approved by the FDA for chronic moderate-to-severe psoriasis patients, ages four to 17 years. It is a tumor necrosis factor (TNF) receptor antagonist, which is also approved for adults with psoriatic arthritis. This agent has the most safety data in children, including well over a decade of prospective registry data for monotherapy and combination treatment with methotrexate for juvenile idiopathic arthritis.