Henoch-Schönlein purpura (HSP) causes the blood vessels in your skin to get inflamed (irritated and swollen). It can also affect blood vessels in the bowel and the kidneys. When the blood vessels in your skin get inflamed, they can bleed, causing a rash that is called purpura. The intestines and the kidneys may also bleed.
The exact cause of HSP is unknown. HSP is caused when a persons immune system doesn't fight an infection like its supposed to. It might be triggered by bacterial or viral infections, medicines, insect bites, vaccinations or exposure to chemicals or cold weather.
There is no specific treatment for Henoch-Schönlein purpura. Bed rest and supportive care such as assuring adequate hydration are helpful. Nonsteroidal anti-inflammatory drugs can relieve joint and soft tissue discomfort. Corticosteroids have some use in patients with severe abdominal pain. However corticosteroids are generally not recommended for treatment of rash, joint pain or renal disease alone.
It is generally a harmless, self-limited condition but needs close follow-up with repeated urinalysis. The illness lasts four to six weeks in most patients. About half of patients may have a recurrence. Long-term follow-up is necessary for patients with kidney involvement.
I may hasten to add that your child specialist is in the best position to take decisions for the welfare of your baby as these are just guidelines, which may or may not be practical to the ground realities faced by your paediatrician. I personally think that the course taken by your paediatrician is the right one. I wish your child a speedy recovery.