SEATTLE The clinical features of lupus in children may be subtle and easily overlooked, Dr. David Sherry said.
Vasculitis, the pathologic hallmark of lupus, can produce a challenging clinical picture with a wide differential diagnosis, noted Dr. Sherry, who is a pediatric rheumatologist at the Children's Hospital of Philadelphia.
"It's such a black hole, a lot of clinicians just don't want to think about it." But clinicians should think about it under certain circumstances, he said.
One is when a child has constitutional symptoms that persist. "When you have a kid who is sick and they are not getting betterthey still have a fever, they are still losing weight, they have an elevated sedimentation rate, and the 'virus' still isn't going awayyou need to think maybe they've got a vasculitic condition," he commented at a meeting sponsored by the American Academy of Pediatrics.
Multiorgan disease can also be a tip-off for vasculitis. "Why should a kid be peeing blood and coughing up blood?" he said. "That's two different organs." Seeing an unusual patient for the symptom, such as a teenager with a heart attack, also should raise a suspicion of vasculitis.
Finally, there is the vasculitic rash, which can have a variety of appearances.
In describing the malar rash of lupus, textbooks often show photos of a vivid, contiguous red rash in the classic butterfly distribution on the cheeks and nose, according to Dr. Sherry. But what is actually seen clinically may instead mimic rosacea, wind chapping, sunburn, or even acne. In addition, in black children, the rash may be subtle and especially hard to identify.
Key features that can help identify a malar rash of lupus include its distribution, typically with crossing over the bridge of the nose and spreading onto the cheeks, and a well-defined border between the affected skin and normal skin. Children with malar rashes usually have other symptoms or clinical findings too.
Additional clues to the presence of lupus can often be found on parts of the body that are easily overlooked on examination, according to Dr. Sherry. For example, children may have a vasculitic rash on their hands or feet, or a painless ulcer on their hard palate. "You need to look up to see the hard palate," he pointed out. "If you look at the back of the throat, you will miss this."
Discoid rash is less common and causes crusts or scabs that scar. "If you lift up these crusts or scabs, you see what's called carpet tackinglittle pinpoints of bleeding underneath." he said. "Discoid lupus especially likes the helix of the ear, so pay attention to the helix."
Children also may have so-called lupus hairs, which are fragile and break easily. "You pull on their hair, you get three, four, or five hairs, even if they just brushed it," he explained. The breakage is accompanied by the presence of short hairs resulting from regrowth.
When lupus is first suspected in children, Dr. Sherry recommended that physicians obtain a complete blood cell count, an erythrocyte sedimentation rate (ESR), a C-reactive protein (CRP) level, a urinalysis, a comprehensive metabolic panel, and an antinuclear antibody (ANA) titer. Lupus has the unique property of producing a high ESR and a normal CRP levelunless the child also has an infection.
An ANA panel can be deferred unless suspicion of the disease is high, he said. Related tests should be guided by symptoms, such as rheumatoid factor assessment in a child with pronounced joint symptoms, creatine kinase assessment in a child with muscle weakness, and coagulation studies in a child with deep venous thrombosis.
Dr. Sherry noted that to be classified as having lupus, children must meet at least 4 of the 11 clinical and laboratory criteria of the American College of Rheumatology, of which a positive ANA titer is merely 1.
In fact, he cautioned, 12%-20% of normal children have a positive ANA titer.
If the ANA result is positive but at a titer of only 1:80 or 1:160, the child is unlikely to have lupus; if it is higher, the ANA panel should be done. "If the panel is negative, you can cool your jets and cool the mom's jets," he said.
Management in children with lupus, in addition to antirheumatic therapy, includes counseling about sun protection because of photosensitivity, antihypertensive therapy when blood pressure is elevated, and attention to calcium and vitamin D status, both because steroid therapy adversely affects bone health and because lower levels of vitamin D have been linked to increased disease activity. "We give these kids calcium and, if they are low in vitamin D, we certainly can give them that too," Dr. Sherry said.