A 1-week-old black infant presents to you for the first time with a large, fairly well-defined, grey-blue lesion over the buttocks bilaterally. The lesion is not palpable, and it is not warm or tender. The mother denies trauma and reports that the lesion has been present since birth. This otherwise well-appearing infant is growing and developing normally and appears normal upon physical examination. Which of the following is the most appropriate course of action in this infant?

(b) Source: (Hay et al, p 384. Kliegman et al, p 2219. McMillan et al, p 828. Rudolph et al, p 1275.) The lesion is a Mongolian spot, a bluish-gray lesion located over the buttocks, lower back, and occasionally, the extensor surfaces of the extremities. These are common in blacks, Asians, and Latin Americans. They tend to disappear by 1 to 2 years of age, although those on the extremities may not fully resolve. Child abuse is unlikely to present with bruises alone; children frequently present with more extensive injuries. Subcutaneous fat necrosis, which may ultimately result in subcutaneous calcifications in the affected area, is usually found as a sharply demarcated, hard lesion on the cheeks, buttocks, and limbs but it usually is red. Hemophilia and vitamin K deficiency rarely present with subcutaneous lesions as described and are more likely to present as a bleeding episode.