[X-ray diagnosis of immunologically induced lung diseases in children and adolescents]

After coverage of pathophysiological mechanisms, radiological symptoms and differential diagnosis of bacterial and opportunistic infections of the bronchopulmonary system are discussed as they occur in humoral, cellular and combined congenital and acquired immune deficiencies. The discussion is based on case reports. Humoral deficiencies cause recurrent and chronic bacterial infections of the bronchopulmonary system, frequently with bronchiectasis. In the case of cellular and combined immune deficiencies, not only bacterial infections but also the very serious opportunistic infections occur. Opportunistic infections of the lung are predominantly caused by Pneumocystis carinii, by the cytomegaly virus, and by fungi such as Candida, Aspergillus and Mucor. Pneumocystis is also the most frequent cause of opportunistic infections of the lungs in children with AIDS. In contrast to the situation in adults, in children a relatively low-grade lymphocytic interstitial pneumonitis occasionally precedes the typical opportunistic infections. Lymphocytic interstitial pneumonitis and Pneumocystis pneumonia can be differentiated from each other easily in children because of their relatively characteristic appearances. Fungal infections, on the other hand, sometimes pose severe diagnostic problems. Radiological chest findings in autoimmune diseases are discussed.