Defer Extensive Work-Up in Most Cases of Ash Leaf Macules

Family Pratice News,  Feb 1, 2000  by Barbara Baker

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MONTEREY, CALIF. -- Most children with just a few ash leaf macules don't require an extensive work-up for tuberous sclerosis, Dr. Sheila F. Friedlander said at the annual meeting of the Pacific Dermatologic Association.

If these children have a normal developmental and neurologic history and no family history of the disease, then it's reasonable to defer an extensive work-up and merely counsel the family to be on the lookout for other possible signs of the disorder, according to Dr. Friedlander, a pediatric dermatologist at Children's Hospital, San Diego.

Results of surveys show that up to 4% of newborns have from one to three hypopigmented macules, and in most cases, this is just a normal finding. But more than three macules should heighten suspicion. It's therefore important to check patients with a Wood's lamp, she said.

Although ash leaf macules are the most common lesions of tuberous sclerosis at birth and during the preschool years, children who have the disease may also have small areas of lightened hair and an increased number of cafe-au-lait macules, Dr. Friedlander noted.

Less commonly they have homogenous brown, fibrous forehead plaques. Facial angiofibromas and periungual fibromas usually don't develop until later childhood or adulthood.

The index of suspicion for tuberous sclerosis should rise precipitously if patients have developmental delay and/or infantile spasms. Studies indicate that tuberous sclerosis may account for 4%-25% of cases of infantile spasms.

It's worth asking about family history of any manifestations of tuberous sclerosis because the disease is an autosomal dominant disorder. However, new gene mutations account for 50%-75% of cases, Dr. Friedlander noted.

If tuberous sclerosis is seriously considered in the differential diagnosis, evaluation of the kidneys is a good idea, regardless of the patient's age, she said. The more worrisome finding is renal angiomyolipomas, but renal cysts are also common in patients with the disease.

Examination of the eye is helpful to detect retinal astrocytomas and hamartomas. An echocardiogram to detect rhabdomyomas is only worthwhile in infancy because these lesions usually regress with age, she said.

Neuroimaging with MRI is controversial. Patients with tuberous sclerosis may have a variety of MRI abnormalities detected, but their presence or absence does not absolutely predict the later development of seizures, Dr. Friedlander said.

COPYRIGHT 2000 International Medical News Group
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