Characteristics of patients with drug resistant and drug sensitive tuberculosis in East London between 1984 and 1992.

BACKGROUND--The aim of this study was to investigate retrospectively factors associated with drug resistant tuberculosis at the London Chest Hospital. METHODS--The microbiology results for patients with tuberculosis at the hospital for the period 1984-92 were reviewed, together with case notes and chest radiographs of all patients with drug resistant tuberculosis and of 101 patients with drug sensitive tuberculosis notified during the same period as a control group. RESULTS--Culture positive pulmonary tuberculosis occurred in 292 patients. Drug resistant strains were isolated from 20 patients (6.8%). Ten of the 292 (3.4%) had strains resistant to a single drug and nine (3.1%) had resistance to more than one first line drug. One patient had strains resistant to isoniazid and capreomycin. Strains resistant to more than one drug were all resistant to isoniazid and rifampicin. In five patients these strains were also resistant to pyrazinamide and in two they were resistant to streptomycin. Single drug resistant strains were resistant to isoniazid (nine patients) or streptomycin (one patient). Among the risk factors studied previous treatment for tuberculosis was the most significant association with drug resistant tuberculosis (7/9) for patients with resistance to more than one drug; 5/11 for single drug resistance compared with 6/101 patients in the drug sensitive group (odds ratio 22.8). Other risk factors were bilateral disease at presentation (odds ratio 8.5), and disease at a young age (odds ratio 1.03). CONCLUSIONS--Previous treatment for tuberculosis and bilateral disease at presentation were found to be more commonly associated with cases of drug resistant than with drug sensitive tuberculosis.     

Hereditary spherocytosis. Recent experience and current concepts of pathophysiology.

Hereditary spherocytosis is a clinically heterogeneous, genetically determined red blood cell membrane disorder resulting in hemolytic anemia. A deficiency of spectrin, the largest and most abundant structural protein of the erythrocyte membrane skeleton, results in the formation of spherocytes which lack the strength, durability, and flexibility to withstand the stresses of the circulation. Clinical manifestations of the disease are primarily dependent on the severity of hemolysis, which additionally results in an increased incidence of pigment gallstones. The likelihood of cholelithiasis is directly related to patient age and is uncommon before 10 years of age. Splenectomy is indicated in virtually every patient. When the disease is diagnosed in early childhood, the risk of overwhelming postsplenectomy sepsis makes it advisable to delay splenectomy until after 6 years of age if possible. At the time of splenectomy, it is important to identify and remove any accessory spleens. If gallstones are present, cholecystectomy should be performed. Although spherocytosis persists following splenectomy, hemolysis is alleviated and clinical cure of the anemia is achieved for most patients. Patients with recessively inherited spherocytosis are exceptions. Although they are significantly benefited by splenectomy, their anemia is not completely corrected. Splenectomy reduces hemolysis in all patients and thereby decreases the risk for development of pigment gallstones. Excision of an enlarged spleen removes the danger of traumatic rupture.     

Unusual Physiologic Melanin Pigmentation of the Tongue

A patient had extensive congenital oral hyperpigmentation of the tongue. The clinical and histologic features set this case apart from any well-delineated disease. Clinically, the congenital onset, the appearance of large black-brownish lesions, the lack of associated systemic abnormalities, and the histologic findings of prominent deposition of melanin in the basal layer support the diagnosis of physiologic melanosis. The macular lesions of the tongue represent discrete depositions of melanin and exemplify soft tissue pigmentation of developmental origin.