What are the most common complications of scid?

Infection. Life threatening infections, which can cause death. See an immunodeficiency specialist if you know a child with scid that has not been fully evaluated by an expert in this area.
Not easy to describe. Symptoms of scid may include a sudden and recurring diarrhea, chronic ear infections, upper respiratory infections and more than one case of pneumonia in a relatively short period of time. Often, children who suffer from a complication of severe combined immunodeficiency will experience sudden weight loss, especially when the immune deficiency is not realized early.