Medical advice needed 12-year-old girl with severe reaction to ibuprofen, weight loss, and appetite loss

Hello everyone, I'm seeking medical insight for a 12-year-old girl who's been struggling with multiple health issues for months, and local doctors haven't been helpful so far.

She had two episodes of severe cold sweating and hypothermia (34°C) shortly after taking ibuprofen (Ardil). Both times, the symptoms appeared within an hour of ingestion. The second time was today. She became pale, sweaty, with cold skin and a low body temperature, needing to be warmed immediately.

She also suffers from:

Severe loss of appetite, eating almost nothing

Rapid weight loss over recent weeks

Chronic stomach pain and a previously diagnosed gastric inflammation

Excessive sweating, especially at night or after minimal activity

Occasional burning urination (once last week)

Poor dental condition and delayed eruption of upper lateral incisors

Constant fatigue and weakness

Doctors have prescribed medications but no proper investigation (labs or imaging) has led to any clear diagnosis. Her mother reports that all basic blood tests were "normal," but no further testing (e.g. for H. pylori, endocrine issues, or autoimmune causes) has been done.

Could this be an allergic or systemic reaction to ibuprofen? Or could something more serious (metabolic, GI, endocrine, etc.) be missed?

Any guidance or suggestions on what tests or specialists to ask for would be deeply appreciated. Thank you so much.