How do individuals with IgA deficiency typically present?

Individuals with IgA deficiency typically present with recurrent infections, particularly affecting the sinuses, lungs, and digestive system. This is primarily due to the critical role that immunoglobulin A (IgA) plays in mucosal immunity. IgA is found in high concentrations in mucosal areas such as the respiratory and gastrointestinal tracts, where it helps to protect against pathogens.

When individuals have a deficiency in IgA, their ability to mount an adequate immune response in these mucosal regions is compromised, making them more susceptible to respiratory and gastrointestinal infections. These recurrent infections can manifest as sinusitis, bronchitis, and gastrointestinal illnesses, reflecting the increased vulnerability of these systems.

The other options do not adequately capture the common presentation of IgA deficiency. For example, while neurological symptoms, skin infections, or gastrointestinal bleeding may occur in various conditions, they are not characteristic features of IgA deficiency. Instead, individuals with this deficiency predominantly experience recurrent mucosal infections rather than isolated or specific symptoms in other bodily systems.