Pneumocystis jiroveci pneumonia in an infant with severe folate deficiency.

Pneumocystis jiroveci pneumonia is rare in immunocompetent children. Severe folate deficiency affects T cell function, potentially increasing susceptibility to opportunistic pathogens. We report the case of an 11-month-old child who developed P. jiroveci pneumonia in the setting of severe nutritional folate deficiency and review the literature regarding the influence of folate on immunity.