The roentgen findings in Pneumocystis carinii pneumonia.

Abstract

Respiratory disorders remain the major cause of infant morbidity and even mortality in spite of many new fields of interest and research by pediatric, surgical, and roentgen investigators. The discouragingly high incidence of death in this category is obviously related to the anatomic state of the lungs and the overall stage of development of the patients. Premature infants, for example, have a high incidence of hyaline membrane disease which does not respond well to treatment and accounts for thousands of deaths each year (8). Also, new entities are becoming apparent—actually new diseases or conditions heretofore unrecognized and included in old nondescript categories. This report will deal with one of the second group. Pneumocystis carinii pneumonia, or interstitial plasma-cell pneumonia, cannot accurately be described as new, since several hundred cases have been reported from Europe as well as some from America (5, 7, 10, 11, 13, 15, 19–22). American reports, however, have been limited to relatively recent identification of isolated cases (10, 15, 17, 18, 20). Much has been written abroad and to a lesser extent in the United States about the etiology, the endemic nature, and other aspects of the disease, but the characteristic roentgen findings have received little attention. The purpose of this paper is twofold. One is to remind the radiologist that this is a clinical problem not as rare as formerly believed. The second is to describe what one of the authors (S. B. F.) feels is a characteristic roentgen diagnostic picture that should facilitate antemortem diagnosis, and lead to effective therapy. Clinical Findings The clinical diagnosis of Pneumocystis carinii pneumonia is nonspecific and is reached only after a process of deduction. The development of an antigen for skin testing does offer hope for a positive diagnosis without resorting to lung biopsy (5). The disease usually attacks the premature or feeble full-term infant during the second to fifth month of life. The onset in most instances is insidious, with a relative absence of symptoms or persistent mild upper respiratory infections. Diarrhea often precedes the full-blown clinical picture. The following findings have been reported as common, even though they are nonspecific in themselves: restlessness, anorexia, dyspnea without fever, tachypnea, cough, increased respiratory rate, cyanosis, and sternal retraction (7, 10, 11, 13–15, 18, 19). The point which cannot be overemphasized is the discrepancy between severe dyspnea and the lack of physical findings. This is probably the single most important clue to the clinical diagnosis. Respiration becomes abdominal, the cough is unproductive, and cyanosis increases in spite of oxygen therapy. Emphysema with a few scattered râles may be the only physical finding. The hemogram is not characteristic. Mortality has been reported to vary from 15 to 100 per cent (10, 15).