What are the causes of neonatal cholestasis, types of esophageal atresia, rare presentations of HSP, and most dangerous causes of arthritis?

Here are the answers to the questions:

1-One of causes Neonatal cholestasis is:
C) Galactosemia
Galactosemia is a genetic metabolic disorder that can lead to liver damage and cholestasis in newborns if not diagnosed and treated early.

2-The commonest type of esophageal atresia is
C. Esophageal atresia with distal fistula
The most common form of esophageal atresia involves the upper esophagus ending in a blind pouch, with the lower esophagus connecting to the trachea via a fistula. This is often referred to as Type C.

3- The rare presentation of HSP is.
B. CNS manifestations
Henoch-Schönlein Purpura (HSP) commonly presents with rash, arthritis, abdominal pain, and renal involvement. Central nervous system (CNS) manifestations like seizures or altered mental status are considered rare complications.

4-The most dangerous cause of arthritis is
A. Malignancy
While many conditions can cause arthritis, malignancy (such as leukemia, lymphoma, or metastatic cancer) is considered the most dangerous cause due to the life-threatening nature of the underlying disease.