At a newborn's 1-month follow-up appointment the parents note a lesion on the child's back that has occasionally appeared raised and fluid filled (left).
One month later, the child presents with multiple tan brown plaques, some with a thickened surface, over the trunk and extremities (right).
You inform the parents:
A. the child needs a bone marrow biopsy
B. the child needs a bone marrow transplant
C. these lesions will fade and resolve by 10-12 years of age
D. the child has neurofibromatosis
E. the child needs a rapid plasma reagin (RPR)
The correct answer is C. Urticaria pigmentosa is the condition of multiple cutaneous collections of mast cells that accumulate during infancy and childhood. The number of lesions can vary from few to innumerable. Childhood urticaria pigmentosa is rarely associated with systemic manifestations. Lesions tend to accumulate during the first few years of life, then stabilize, and gradually fade and involute by early adolescence. Some patients will have complete clearance; others will experience significant improvement. Adult-onset mast cell disease is associated with an increased risk of mast cell leukemia and other myelodysplasias; this has not been observed in the juvenile form.
Question & Explanation and Photos: Daum RS, Canel JJ. McGraw-Hill Specialty Board Review: Pediatrics, 2e; 2013.