My 9 year old son started Singulair 5mg about 8 months ago. Shor...

EOSINOPHILIA is an increased number of eosinophils - a type of white blood cell - which usually occurs in small numbers in the blood and intestine. When they appear in high quantities in other parts of the body they can cause inflammation. For example, if eosinophils invade the esophagus, the following symptoms may occur: nausea, regurgitation, vomiting, abdominal pain, a burning feeling similar to acid reflux (heartburn), difficulty swallowing and gagging, feeling like something is stuck in the throat. Children may be reluctant to eat and develop irrational aversions to certain foods. Antacids do not help.*****

VASCULITIS is an inflammation of the blood vessels. In vasculitis, the body’s immune system mistakenly attacks the body’s own blood vessels, causing inflammation that can damage the blood vessels and lead to a number of serious complications.

Vasculitis is sometimes a side effect of the body's response to an infection or an allergic reaction to a medication.

Symptoms may include include general aches, pains, and sickness, such as fever, loss of appetite, weight loss, fatigue (feeling tired) and weakness

I posted that as vasculitis is a known side effect of singulair,go to parentsforsafety.org for more info good luck

I had the same experience with my 7 year old son. He would eat VERY small portions and ask to lay down because his tummy hurt. I took him off Singulair in December and he still complained about stomach pain in April. I took him in to see the doctor and she put him on Prevacid because it "sounded like" an ulcer or gastrointestinal abrasion. I asked if this could be a side effect of Singulair and she had never heard it to be. The NUMBER ONE side effect listed on the drugs website is STOMACH PAIN. Take your son back and have them do an endoscopy.