Hunter syndrome (MPS II) can predispose pediatric patients to repeat respiratory and ear infections, which, often present before Hunter syndrome is diagnosed.1,2,3 Alongside these recurrent infections, other Hunter syndrome symptoms, including chronic rhinorrhoea, nasal obstruction, noisy breathing, hearing loss and enlarged adenoids and tonsils, in addition to a distended abdomen (hepatosplenomegaly) and chronic diarrhoea, may all contribute to Hunter syndrome, being mistaken to have an infectious/immune-related cause.4,5,6 Therefore, an undiagnosed Hunter syndrome patient may be referred to an immunologist or allergist to manage the recurrent infections and pulmonary symptoms.1,2,3 Click here to learn more about the signs and symptoms of Hunter syndrome.
The American Academy of Allergy, Asthma & Immunology (AAAAI) and the American College of Allergy, Asthma & Immunology (ACAAI) practice parameter for the diagnosis of primary immunodeficiency disorders note the need to exclude the possibility of anatomical or biochemical causes of infection susceptibility, before focusing on investigating immunodeficiency.7 Click here to download a poster highlighting the key exclusion step in the AAAAI/ACAAI practice parameters.
Biochemical and anatomical changes to airways are an underlying cause of recurrent respiratory infections in Hunter syndrome.1,8 Hunter syndrome patients may have enlarged tonsils, adenoids, gums and tongue, and tracheomalacia, and thick secretion, including chronic rhinorhoea.4,8

