What is often the first indication of chronic granulomatous disease?

Chronic granulomatous disease (CGD) is primarily characterized by a defect in the body's ability to produce reactive oxygen species (ROS) in phagocytes, which leads to increased susceptibility to certain infections. The first indication of CGD often presents as recurrent bacterial or fungal infections, particularly from catalase-positive organisms such as Staphylococcus and Aspergillus species. These clinical manifestations, which can include abscess formation and a history of recurrent infections, serve as the initial signs prompting further investigation into the underlying cause.

While laboratory tests such as the nitroblue tetrazolium test and flow cytometry using dihydrorhodamine are important in confirming the diagnosis of CGD, they are not the primary indication of the disease. The presence of non-phosphorylated targets is not relevant to the diagnosis of CGD and does not indicate the disease status in patients. Thus, the characteristic signs and symptoms observed clinically are the first and most telling indicators of chronic granulomatous disease.