WAIKOLOA, HAWAII – Guttate psoriasis in children warrants more aggressive monitoring and treatment in an effort to head off more severe disease later, according to Dr. Wynnis L. Tom.

Pediatric psoriasis presenting initially as guttate disease is more likely to progress to severe psoriasis prior to adulthood than if the initial presentation took the form of plaque psoriasis, according to data from a multicenter U.S. study of the clinical manifestations of pediatric psoriasis.

The cross-sectional study included 181 children aged 5-17 years with plaque psoriasis, and the results highlighted important differences between childhood-onset and adult-onset disease, Dr. Tom said at the Hawaii Dermatology Seminar sponsored by Global Academy for Medical Education/Skin Disease Education Foundation.

About 40% of cases of pediatric psoriasis that presented initially as guttate psoriasis progressed to chronic disease. That was not a higher proportion than in children whose initial disease was plaque psoriasis, said Dr. Tom of the University of California, San Diego, and Rady Children’s Hospital. However, 36% of youths with severe psoriasis had a history of disease onset with guttate morphology compared with 22% of those with mild disease, she said.

The peak severity of psoriasis was defined historically as either mild or severe based upon body surface area involvement and Physician Global Assessment.

Overall, 79% of study participants had a history of scalp psoriasis and 39% had a history of nail involvement. However, these disease expressions were unrelated to psoriasis severity.

Boys were three times more likely than girls to have had nail involvement, but 60% less likely to have a history of scalp involvement. These sex-related differences probably reflect koebnerization, Dr. Tom said.

Approximately 5% of the patients had psoriasis restricted to their face alone. Among those with body involvement, the face was included in nearly half of cases.

Session chair Dr. Lawrence F. Eichenfield praised this study (Pediatr. Dermatol. 2013;30:424-8), on which Dr. Tom was a coauthor, as one of the top articles in the field of pediatric dermatology published within the past year. Although various studies indicate that 27%-45% of all cases of psoriasis begin in childhood, the clinical aspects of pediatric psoriasis haven’t been well characterized until now, said Dr. Eichenfield, professor of clinical pediatrics and medicine and chief of pediatric and adolescent dermatology at the University of California, San Diego.

Dr. Eichenfield also singled out Dr. Tom as coauthor of yet another of his top picks of recently published studies on the topic of pediatric psoriasis. This cross-sectional study included 409 psoriasis patients aged 5-17 years in nine countries. The prevalence of excess adiposity as defined by a body mass index at the 85th percentile or greater was 38% among the psoriatic children compared with 21% in matched controls. The likelihood of obesity as defined by a BMI in the 95th percentile or higher was 4.9-fold greater in children with severe psoriasis than in controls, and 3.6-fold greater in those with mild psoriasis compared than in controls. Among U.S. patients, the psoriasis/obesity association was magnified such that American children with severe and mild psoriasis were respectively 7.6-fold and 4.7-fold more likely to be obese than controls (JAMA Dermatol. 2013;149:166-76).

Central adiposity – an element of metabolic syndrome associated with increased cardiovascular risk in adults – was present as defined by waist circumference greater than the 90th percentile in 21% of youths with severe psoriasis, 14% with mild disease, and 9% of controls. In U.S. participants, these figures ballooned to 31%, 21%, and 12%, respectively.

Dr. Tom cited evidence from yet another study in which she was a coinvestigator suggesting that obesity may be a risk factor for pediatric psoriasis, rather than the other way around. In this three-center study, nearly all of a group of pediatric psoriasis patients were overweight or obese for at least 2 years prior to their psoriasis onset.

Current National Psoriasis Foundation guidelines recommend initiating cardiovascular risk factor screening "as early as age 20." Dr. Tom is among those seeking to revise the guidelines to extend screening to pediatric psoriasis patients. She said she now recommends consideration of cardiovascular screening in overweight and obese pediatric psoriasis patients – including monitoring of blood pressure, lipids, fasting blood glucose, and liver enzymes – along with hard-hitting guidance on dietary modifications, weight loss, and the importance of exercise.

"Ongoing studies are assessing the need for screening labs for nonoverweight children with psoriasis. Hopefully this will be sorted out soon as a group in our field. We’re hoping for updated guidelines," she said.

Dr. Tom disclosed serving as a financially uncompensated investigator for Amgen and Anacor.

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bjancin@frontlinemedcom.com

Key studies show distinctive features of pediatric psoriasis