Brief Answer:
Probably a normal symptom after a cold, you should not be worried.

Detailed Answer:
Hello dear and welcome to ‘Ask A Doctor’ service. I have reviewed your query and here is my advice.

The symptoms of your son seem to be related to an upper respiratory tract infection.

Nosebleeding is a common symptom after this infection.

The infection irritates and dries out nasal membranes.

This cause crusts that may itch and then bleed.

I suggest to use nose lubrificants for local application.

I suggest water-based lubricants, such as K-Y jelly.

I also suggest to give your son a lot of liquids.

I recommend to use a humidifier at home to prevent dry air, which may trigger the symptoms.

He should blow gently the nose into a soft tissue.

You should not be worried, the nosebleeding will pass in a few days.

Hope I have answered your query. Let me know if I can assist you further.

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