Cutaneous Nodule From Heel Pricks

This single cutaneous nodule on the right heel of a 14-month-old girl had been present for 2 months. The child was born to a 34-year-old, gravida 1, para 2 mother at 35 weeks’ gestation after a cesarean delivery. It was a twin pregnancy, and the patient was the second born.

At birth, the infant’s weight was 2450 g and length 48 cm. In the immediate neonatal period, she was lethargic, and penicillin and gentamicin were started for suspected sepsis. The antibiotics were subsequently discontinued when culture results were negative. Jaundice was noted on the third day of life, and she was pricked in
the heels on several occasions for the monitoring of serum bilirubin levels. She did not require phototherapy. The mother noticed the nodule on the right heel when clothing the infant.

The firm white nodule was about 2 mm in diameter. It was nontender. The remaining examination findings were normal. A cutaneous nodule from heel pricking was diagnosed. Histologically, the nodule has a rim of irregular calcification surrounded by a fibrous connective tissue and a mononuclear inflammatory infiltrate. These calcified nodules have been reported to occur more commonly in high-risk pre-term infants after single or multiple heel pricks.1,2

Of the proposed mechanisms of action leading to calcified nodules, one hypothesis is that the injured tissue results in release of alkaline phosphatase, which leads to a rise in pH and consequently precipitation of calcium.1 Another theory postulates that needle trauma causes epidermal implantation cysts, which may then calcify.3

Dystrophic calcification of the skin can also occur following trauma from surgery, burns, and electrocution.1

Typically, the white or yellow lesion appears between 4 and 12 months of age and resolves 14 to 18 months later by transepidermal elimination.1,2 It is characteristically asymptomatic and often solitary. Rarely, the lesion may persist and interfere with footwear, causing pain and requiring excision.1,2