X-linked agammaglobulinemia (XLA) is a hereditary humoral immunodeficiency that results from Bruton’s tyrosine kinase (BTK) gene mutations. These mutations cause defects in B-cell development, resulting in the virtual absence of these lymphocytes from the peripheral circulation. Consequently, this absence leads to a profound deficiency of lg all isotypes, and an increased susceptibility to encapsulated bacterial infections. A 15-month-old Korean boy...

Isolated sphenoid sinusitis is a rare disease in children, and its symptoms are often nonspecific and confusing. Rarely, severe headache can be the first or only symptom of isolated sphenoid sinusitis. New daily persistent headache (NDPH) is a form of chronic daily headache that may have features of both migraines and tension-type headaches. NDPH is difficult to diagnose and requires...