Capillary Density Marks Active Dermatomyositis

Portland, Ore. - Children with dermatomyositis should not be taken off treatment when their distal fingernail beds have fewer than six capillaries per millimeter, even if they appear to be in remission, advised Dr. Brian Feldman.

Capillary vasculopathy is the primary pathogenic finding in dermatomyositis, which makes capillary density of the nail bed a sensitive marker of disease activity, reported Dr. Feldman, a professor of pediatrics at the University of Toronto and a pediatric rheumatologist at the Hospital for Sick Children in that city. He is head of the hospital’s dermatomyositis clinic.

Normal density is 7-11 nail bed capillaries per millimeter. That number is reduced in active dermatomyositis, often to three nail bed capillaries per millimeter, and those capillaries are usually tortuous, dilated, and bushy. Cuticle overgrowth and periungual erythema are also common.

Lower densities have proved to be “such a good indication of what’s going on inside the body that I won’t take children [who appear to be in remission] off treatment if the capillary density is abnormal [because] they will often flair within weeks,” Dr. Feldman said.

He uses a Nikon stereomicroscope to make the assessment.

He and his colleagues at other institutions have discovered that systemic disease is less common in children with dermatomyositis than in adults, and fever is less common at presentation. Heart involvement is also less common, and dermatomyositis in children is “not associated with malignancy,” he said.

At his clinic, MRI has generally replaced muscle biopsy because it is less invasive. To allow for immediate home treatment, Dr. Feldman usually initiates therapy with oral rather than intravenous formulations of prednisone and methotrexate.

The standard initial dose of oral prednisone is 2 mg/kg per day; more aggressive corticosteroid dosing has not been shown to improve 3-year outcomes, Dr. Feldman said (Arthritis Rheum. 2008;59:989-95).

He and his colleagues have found that adding methotrexate 15 mg/m2 per week to the corticosteroid dose allows for a more rapid taper off steroids, typically within a year.

Compared with children treated for 2 years or longer with steroids alone, children who were treated with both agents and tapered off steroids more quickly have greater height velocity during the first year of treatment and smaller increases in body mass index over the first 2 years (Arthritis Rheum. 2005;52:3570-8).

Intravenous immunoglobulin is a useful adjunct to therapy, particularly when methotrexate alone fails to heal Gottron’s papules or other dermatomyositis skin manifestations. “Instead of adding back or increasing prednisone, IV immunoglobulin seems to work a charm,” he said.

Cyclosporine may help, as well, to restore muscle strength in children with dermatomyositis, Dr. Feldman said.

In a recent study, he and his colleagues found that the median time to remission among 84 patients with pediatric dermatomyositis was 4.67 years following initiation of treatment.

They found that the presence of Gottron’s papules at 3 months, despite treatment, was the earliest predictor of a longer time to remission.

At 6 months, the presence of nail fold abnormalities and rash also predicted a longer time to remission (Arthritis Rheum. 2008;58:3585-92).

“If the rash is gone in 3 months, children are twice as likely to go into remission” at some point, Dr. Feldman said at the meeting. Otherwise, more than half of patients will still have active disease after 10 years.

Still, with modern treatments, “functional outcome is good, even with chronic disease,” he said.

Disclosures: Dr. Feldman reported having no financial conflicts.

Portland, Ore. - Children with dermatomyositis should not be taken off treatment when their distal fingernail beds have fewer than six capillaries per millimeter, even if they appear to be in remission, advised Dr. Brian Feldman.

Capillary vasculopathy is the primary pathogenic finding in dermatomyositis, which makes capillary density of the nail bed a sensitive marker of disease activity, reported Dr. Feldman, a professor of pediatrics at the University of Toronto and a pediatric rheumatologist at the Hospital for Sick Children in that city. He is head of the hospital’s dermatomyositis clinic.

Normal density is 7-11 nail bed capillaries per millimeter. That number is reduced in active dermatomyositis, often to three nail bed capillaries per millimeter, and those capillaries are usually tortuous, dilated, and bushy. Cuticle overgrowth and periungual erythema are also common.

Lower densities have proved to be “such a good indication of what’s going on inside the body that I won’t take children [who appear to be in remission] off treatment if the capillary density is abnormal [because] they will often flair within weeks,” Dr. Feldman said.

He uses a Nikon stereomicroscope to make the assessment.

He and his colleagues at other institutions have discovered that systemic disease is less common in children with dermatomyositis than in adults, and fever is less common at presentation. Heart involvement is also less common, and dermatomyositis in children is “not associated with malignancy,” he said.

At his clinic, MRI has generally replaced muscle biopsy because it is less invasive. To allow for immediate home treatment, Dr. Feldman usually initiates therapy with oral rather than intravenous formulations of prednisone and methotrexate.

The standard initial dose of oral prednisone is 2 mg/kg per day; more aggressive corticosteroid dosing has not been shown to improve 3-year outcomes, Dr. Feldman said (Arthritis Rheum. 2008;59:989-95).

He and his colleagues have found that adding methotrexate 15 mg/m2 per week to the corticosteroid dose allows for a more rapid taper off steroids, typically within a year.

Compared with children treated for 2 years or longer with steroids alone, children who were treated with both agents and tapered off steroids more quickly have greater height velocity during the first year of treatment and smaller increases in body mass index over the first 2 years (Arthritis Rheum. 2005;52:3570-8).

Intravenous immunoglobulin is a useful adjunct to therapy, particularly when methotrexate alone fails to heal Gottron’s papules or other dermatomyositis skin manifestations. “Instead of adding back or increasing prednisone, IV immunoglobulin seems to work a charm,” he said.

Cyclosporine may help, as well, to restore muscle strength in children with dermatomyositis, Dr. Feldman said.

In a recent study, he and his colleagues found that the median time to remission among 84 patients with pediatric dermatomyositis was 4.67 years following initiation of treatment.

They found that the presence of Gottron’s papules at 3 months, despite treatment, was the earliest predictor of a longer time to remission.

At 6 months, the presence of nail fold abnormalities and rash also predicted a longer time to remission (Arthritis Rheum. 2008;58:3585-92).

“If the rash is gone in 3 months, children are twice as likely to go into remission” at some point, Dr. Feldman said at the meeting. Otherwise, more than half of patients will still have active disease after 10 years.

Still, with modern treatments, “functional outcome is good, even with chronic disease,” he said.

Disclosures: Dr. Feldman reported having no financial conflicts.

Portland, Ore. - Children with dermatomyositis should not be taken off treatment when their distal fingernail beds have fewer than six capillaries per millimeter, even if they appear to be in remission, advised Dr. Brian Feldman.

Capillary vasculopathy is the primary pathogenic finding in dermatomyositis, which makes capillary density of the nail bed a sensitive marker of disease activity, reported Dr. Feldman, a professor of pediatrics at the University of Toronto and a pediatric rheumatologist at the Hospital for Sick Children in that city. He is head of the hospital’s dermatomyositis clinic.

Normal density is 7-11 nail bed capillaries per millimeter. That number is reduced in active dermatomyositis, often to three nail bed capillaries per millimeter, and those capillaries are usually tortuous, dilated, and bushy. Cuticle overgrowth and periungual erythema are also common.

Lower densities have proved to be “such a good indication of what’s going on inside the body that I won’t take children [who appear to be in remission] off treatment if the capillary density is abnormal [because] they will often flair within weeks,” Dr. Feldman said.

He uses a Nikon stereomicroscope to make the assessment.

He and his colleagues at other institutions have discovered that systemic disease is less common in children with dermatomyositis than in adults, and fever is less common at presentation. Heart involvement is also less common, and dermatomyositis in children is “not associated with malignancy,” he said.

At his clinic, MRI has generally replaced muscle biopsy because it is less invasive. To allow for immediate home treatment, Dr. Feldman usually initiates therapy with oral rather than intravenous formulations of prednisone and methotrexate.

The standard initial dose of oral prednisone is 2 mg/kg per day; more aggressive corticosteroid dosing has not been shown to improve 3-year outcomes, Dr. Feldman said (Arthritis Rheum. 2008;59:989-95).

He and his colleagues have found that adding methotrexate 15 mg/m2 per week to the corticosteroid dose allows for a more rapid taper off steroids, typically within a year.

Compared with children treated for 2 years or longer with steroids alone, children who were treated with both agents and tapered off steroids more quickly have greater height velocity during the first year of treatment and smaller increases in body mass index over the first 2 years (Arthritis Rheum. 2005;52:3570-8).

Intravenous immunoglobulin is a useful adjunct to therapy, particularly when methotrexate alone fails to heal Gottron’s papules or other dermatomyositis skin manifestations. “Instead of adding back or increasing prednisone, IV immunoglobulin seems to work a charm,” he said.

Cyclosporine may help, as well, to restore muscle strength in children with dermatomyositis, Dr. Feldman said.

In a recent study, he and his colleagues found that the median time to remission among 84 patients with pediatric dermatomyositis was 4.67 years following initiation of treatment.

They found that the presence of Gottron’s papules at 3 months, despite treatment, was the earliest predictor of a longer time to remission.

At 6 months, the presence of nail fold abnormalities and rash also predicted a longer time to remission (Arthritis Rheum. 2008;58:3585-92).

“If the rash is gone in 3 months, children are twice as likely to go into remission” at some point, Dr. Feldman said at the meeting. Otherwise, more than half of patients will still have active disease after 10 years.

Still, with modern treatments, “functional outcome is good, even with chronic disease,” he said.

Disclosures: Dr. Feldman reported having no financial conflicts.