Which of the following is not true about late onset Hemorrhagic disease of Newborn (HDN) ?
**Core Concept**
Late Onset Hemorrhagic Disease of Newborn (HDN) is a condition caused by vitamin K deficiency, leading to coagulopathy and bleeding. It typically presents in the first few weeks of life, after the initial newborn period.
**Why the Correct Answer is Right**
Late Onset HDN is characterized by a deficiency in vitamin K-dependent clotting factors, such as prothrombin (factor II), factor VII, factor IX, and factor X. This deficiency impairs the body's ability to form blood clots, leading to bleeding manifestations. The liver, a key site of vitamin K-dependent clotting factor synthesis, is affected in late onset HDN.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because late onset HDN can indeed present with bleeding manifestations, such as petechiae, ecchymoses, or gastrointestinal bleeding.
**Option B:** This option is incorrect because vitamin K supplementation is the mainstay of treatment for late onset HDN, helping to restore normal clotting factor levels.
**Option C:** This option is incorrect because late onset HDN is associated with a deficiency in vitamin K-dependent clotting factors, not an excess.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that late onset HDN can occur in breastfed infants, particularly if their mothers have a history of vitamin K deficiency or are taking medications that interfere with vitamin K metabolism.
**Correct Answer:** C.