Which condition primarily affects red blood cells when exposed to certain foods or infections?

The condition that primarily affects red blood cells when exposed to certain foods or infections is G6PD deficiency. This is a genetic disorder in which the body does not have enough of the enzyme glucose-6-phosphate dehydrogenase, which is crucial for the proper functioning of red blood cells.

Individuals with G6PD deficiency are particularly sensitive to specific triggers including certain foods (such as fava beans) and infections. When exposed to these triggers, the enzyme deficiency can lead to oxidative stress, resulting in hemolytic anemia. This occurs because red blood cells become damaged and are destroyed prematurely.

In contrast, the other conditions mentioned do not primarily impact red blood cells in the same way. For instance, phenylketonuria affects the metabolism of phenylalanine rather than red blood cells. Congenital adrenal hyperplasia primarily involves the adrenal glands and the production of hormones, while galactosemia is a metabolism disorder affecting the processing of galactose, without a direct impact on red blood cells in response to trigger foods or infections. Thus, G6PD deficiency is the correct answer because it specifically relates to the health of red blood cells in context to certain exposures.