Dusky bullae on the lower abdomen

A pregnant black woman, aged 37 years, who had a history of pre-eclampsia and pulmonary embolism and was on subcutaneous heparin, presented to labor and delivery with a tender, 4-cm dusk, and erythematous patch on the lower abdomen.

On admission, it was noted that other similar-appearing lesions continued to occur, all at sites where subcutaneous heparin had been administered. A ...