A 9 year old boy presents with mild facial swelling for 2 weeks, in association with a nonproductive cough. There was no history of fever, headache, rhinorrhea, or pruritis.

His mother had taken him to a primary care practitioner 1 week ago, who had subsequently prescribed antihistamines. These had not relieved his symptoms.

His mother mentions that he has also been somewhat tired and lethargic for the last couple of months.

His birth, medical, surgical and family histories are completely unremarkable. A full blood count, urinalysis, renal functions, and serum electrolytes are all found to be normal