AT WCPD 2017

CHICAGO (FRONTLINE MEDICAL NEWS) – With no consensus guidelines, rheumatologists and dermatologists have significant practice-based differences in their treatment of children with discoid lupus erythematosus, according to a survey of the two specialties.

The survey’s results from 57 pediatric dermatologists and 47 pediatric rheumatologists showed a lack of consensus between the two specialties in how to screen for systemic lupus erythematosus (SLE). The two specialties also differed in identification of which features of discoid lupus erythematosus (DLE) might predispose children to developing SLE, and in some therapy choices for DLE.

Although rare in children, DLE may develop into systemic lupus erythematosus in about 25%-30% of pediatric patients, according to Lisa Arkin, MD, who shared the survey results during a poster presentation at the World Congress of Pediatric Dermatology.

Dr. Arkin and her colleagues conducted a Web-based survey to examine differences in DLE treatment practice patterns between pediatric dermatologists and pediatric rheumatologists. They sent the survey to 292 members of the Childhood Arthritis and Rheumatology Research Alliance ( CARRA ), and to 200 members of the Pediatric Dermatology Research Alliance ( PeDRA ), and received responses from 44% of the rheumatologists and 56% of the dermatologists. Of those, 57 dermatologists and 47 rheumatologists met inclusion criteria for the study.

More than half of the respondents in each specialty had seen fewer than 10 patients with skin-limited DLE, and fewer than 10 patients with SLE and DLE, over the course of their careers, said Dr. Arkin , director of pediatric dermatology at the University of Wisconsin, Madison.

Consensus was defined by Dr. Arkin and her colleagues as greater than 70% agreement from both specialties, and 2-sided P values less than .05 showed practice differences between rheumatologists and dermatologists.

Clinicians reached a consensus that the presence of either arthritis or nephritis in a pediatric patient with DLE put the patient at high risk for SLE. Arthritis was identified as a high-risk feature by 41 of 57 dermatologists (72%) and 36 of 47 rheumatologists (77%), while nephritis was seen as a high-risk feature by 39 dermatologists (68%) and 37 rheumatologists (79%). However, said Dr. Arkin, “no other features from a list of 30 risk factors including demographics, clinical, or laboratory features achieved consensus.”

In deciding which laboratory studies to order to screen for SLE upon DLE diagnosis, 26 dermatologists (46%) and 38 rheumatologists (81%) choose a full screening panel, according to the survey results. That was a significant between-specialty difference (P less than .001). The full panel consisted of obtaining a complete blood count with differential, testing for renal and hepatic function, obtaining the erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) level, and doing urine studies. The panel also included testing for complements, autoantibodies including anti–double-stranded DNA, single-stranded A and B, ribonucleoprotein, anti-Smith, and antiphospholipid antibodies.

However, when individual laboratory studies were examined, several did achieve consensus for baseline screening. Those included the CBC with differential; urinalysis (but not urine protein creatinine), ESR (but not CRP); complement, renal, and hepatic function testing; and most autoantibody testing (but not antiphospholipid antibody testing). Where there were differences in likelihood to order a test, rheumatologists were more likely to order the test than dermatologists.

In deciding on initial treatment, “rheumatologists were more likely to always initiate hydroxychloroquine than dermatologists,” said Dr. Arkin. Of the rheumatologists, 49% always initiated hydroxychloroquine, compared with 14% of the dermatologists (P less than .001).

In contrast, “dermatologists were more likely to always initiate topical therapy than the rheumatologists,” said Dr. Arkin. Topical therapy was always started by 81% of the dermatologists and 33% of the rheumatologists (P less than .001).

Although the specialties differed in whether they always initiated a certain treatment, “hydroxychloroquine achieved consensus as first-line therapy,” Dr. Arkin noted, with 81% of dermatologists and 87% of rheumatologists choosing hydroxychloroquine when the survey asked for a first-line systemic therapy.

There was no consensus about which agents were best for add-on therapy. Of the dermatologists, 32% would sometimes use methotrexate, which was used by 21% of rheumatologists for refractory skin disease. Quinacrine was used as add-on therapy by 21% of dermatologists and 15% of rheumatologists. Rheumatologists were significantly more likely to add dapsone than dermatologists (28% vs. 5%, P = .002).

The survey points to the need to develop consensus guidelines in the treatment of pediatric DLE, said Dr. Arkin. “Knowledge gaps include risk factors for SLE, optimal screening, and therapy,” she explained. “Collection of robust longitudinal data will aid in developing pediatric consensus guidelines for DLE.”

Dr. Arkin had no conflicts of interest.

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