Haemophilus influenzae type D infection and IgG2 deficiency in a patient with chronic mucocutaneous candidiasis

A 14 year old boy with chronic mucocutaneous candidiasis and persistent pulmonary infection caused by Haemophilus influenzae and Streptococcus pneumoniae is reported. Initial bacterial culture studies showed H. influenzae type B and S. pneumoniae as causative agents. H. influenzae type D was constantly isolated from the patient's sputum. Abnormally low levels of serum immunoglobulin G2 (IgG2) found in the patient may have contributed to the pulmonary infection and H. influenzae type D may be an important causative agent in immunodeficient patients.