Observations on the natural history of dactylitis in homozygous sickle cell disease.

The incidence of the hand-foot syndrome (dactylitis) has been studied in a group of 233 children with homozygous sickle cell (SS) disease followed prospectively from birth. Dactylitis affected 45% of the children by the age of 2 years, with most cases occurring before this age. Episodes were significantly more common during colder months of the year, similar to the seasonal relationship previously noted in painful crises. Comparison of hematologic indices at age 6 months in patients with and without development of dactylitis indicated a lower fetal hemoglobin and higher reticulocyte counts in affected patients. The occurrence of dactylitis in combination with low fetal hemoglobin may serve to identify high-risk patients with SS disease.