Pneumococcal soft-tissue infections: possible association with connective tissue diseases.

Streptococcus pneumoniae is not a well-recognized cause of soft-tissue infections. In less than 4 years, 12 cases of pneumococcal soft-tissue infection were identified through discussions with infections disease subspecialists in the Philadelphia area. Principal sites of involvement included skin and fascia, tongue, epiglottis, thyroid, brain, and breast. Pneumococcal bacteremia was documented in six cases (50%); in three of these, pneumococci were also cultured from the involved soft tissues. In the cases in which bacteremia was not demonstrated, pneumococci were isolated from the infected sites. Six patients had connective tissue diseases, of which five were diagnosed as systemic lupus erythematosus. Four of these patients were receiving corticosteroids when their infections developed. Two additional patients were HIV-seropositive intravenous drug users. S. pneumoniae may be a more important cause of soft-tissue infections than previously appreciated, especially in patients with connective tissue diseases.

Anergy in tuberculosis.

Anergy in tuberculosis is of considerable clinical and immunological interest. Although negative skin reactions may be secondary to improper tuberculin testing or to certain diseases, drugs, vaccinations and constitutional factors known to affect cell-mediated immunity, often no underlying explanation is apparent. Unexplained negative reactions occur with a highly variable frequency in a wide variety of tuberculous infections. Anergy in tuberculosis is usually generalized, is often accompanied by other immunologic abnormalities, and frequently disappears as the disease is treated. Most anergic patients do not differ substantially from reactive patients in clinical features or prognosis. The mechanism of anergy in tuberculosis is unknown, but leading hypotheses suggest that immunologic compartmentalization, suppressor cells, or serum inhibitors (perhaps of mycobacterial origin) may be involved.