Brief Answer:
It's not normal. Home care/ expert help can stop & prevent it.

Detailed Answer:
Hi XXXX,
Thanks for the query.
I have read your query carefully.In swelling of face, when nasal bleed starts, naturally you are scared.Let me tell you in the beginning only.. that nasal bleeding is NEVER NORMAL. any time it happens immediate care must be taken.
Angioeedema is characterized by sudden swelling of Skin & subcutaneous tissue along with mucus membrane & sub mucus membrane of mouth, throat & tongue. Nasal mucus membrane is not involved ,So we can say nasal bleeding is not seen in angioedema normally.
Angioedema is mostly allergic in origin. usually accompanied by red rash ( urticaria) & itching.
* The nasal bleeding your son has may be due to following causes-
- Exposure to extreme temperature.
- Hereditary predisposition.
- Local trauma( external trauma / miner trauma like one following pulling out solidified nasal secretions ( crust)
- Common cold with sinusitis causing inflammation of nasal passage , infection may lead to nasal bleeding ( may be due to infection or forceful nasal blowing )
In you son's case- the same allergy causing angioedema ..might have caused nasal congestion ( common cold , sinusitis ) & bleeding.
- Blood causes like anemia, blood dyscrasias,vitamin C & K deficiency may cause it & needs to be excluded.
- some drugs ( like anti inflammatory drug Ibuprofen which might have been given to control swelling in your son's case ) have side effect of nasal bleeding.
* Home management- The nasal bleeding can be managed by -
- Local cold compression/ pressure.( applied by pinching soft fleshy part of nose directly.
- Application of local medicines ( Phenylepinephrin _ by doctor's advise )
Specialist's advise- if it is not controlled by these OR even after control , to investigate & treat basic cause of bleeding.. consultation of ENT specialist is needful.
- Doctor controls the nasal bleed by nasal packing with medicinal packs/cauterizing the bleeder.
After controlling bleeding, Doctor will investigate to find cause & give specific treatment.( antibiotic, decongestants, hemostatic agents, anti allergic drugs )as per need.
* I feel this clarifies that nasal bleed is never normal, it indicates injury to delicate/ vascular nasal mucosa & may cause serious problem,if not controlled in time. But when managed methodically with an expert's advise . it can be controlled & prevented in future very well.
I Hope the answer has been informative & helpful to you.. any follow up query is welcome.
Please rate the answer before you close the query.
Thanks.

---