Pharmacotherapy of ectoparasitic infections

Epizoonoses such as scabies, lice and cimicosis are common, vexing disorders that occur worldwide. Historically, many treatment modalities have been employed in the management of these disorders, and most of the drugs described in this review are of historical interest and no longer recommended or in widespread use because of their wide spectrum of adverse effects. More recently, reports documenting resistance against various antiectoparasite drugs, complicated and severe courses of the diseases, and adverse effects of drug therapy have prompted the development of new treatment strategies and drugs for optimal disease management. Because the strategies currently recommended for the treatment of ectoparasites differ worldwide, this review proposes a rational approach to selecting the best therapeutic agent by comparing the pharmacokinetics, pharmacodynamics, drug efficacy and adverse effects. A literature search of the currently Internet accessible libraries PubMed, Medline and Ideal library, of citations of articles found there, and from communications with the Federal Institute for Drugs and Medical Devices, Germany, was conducted based on this approach. One major observation of this literature search is that permethrin is the treatment of choice for lice and scabies in the US and in Great Britain, whereas lindane is still recommended for scabies in most other European countries because of its longer-standing record of effectiveness. Although permethrin has not yet been proven to be more effective than lindane in treating infections with these ectoparasites, it currently appears to have the best efficacy versus safety profile of topical treatments for scabies and lice. Ivermectin is a newer oral drug for the treatment of ectoparasites, which has been used with great success in the treatment of onchocercosis and other endoparasites. Although ivermectin appears to be a promising drug, its role in the treatment of ectoparasitic infections will be clarified as more study data become available. Finally, it is important to emphasise the clinical aspects of ectoparasite therapy and that providing the patient with optimal instructions on the use of topical therapeutics is of great importance in avoiding adverse effects and assuring complete removal of the ectoparasite, thereby avoiding the development of drug-resistance.     

Lymphocyte abnormalities predicting a poor prognosis in Hodgkin's disease. A long-term follow-up.

Two hundred sixty-two adult patients with Hodgkin's disease (HD) were studied. Incorporation of carbon-14-thymidine was measured in unstimulated monocyte-depleted lymphocyte cultures, and in cultures activated by concanavalin A (Con-A) before institution of therapy in all patients. Total blood lymphocytes and T-cell subsets were enumerated in the last 108 patients. Patients had significantly decreased total (CD3+, CD4+, CD8+) and relative (CD3+, CD4+) T-cell counts compared with healthy controls. Stage IV patients tended to have lower total lymphocyte and subset counts than remaining patients. However, significantly reduced total lymphocyte and CD8+ counts were only observed in comparison to patients in clinical stage II. Thirty-three percent of patients had an increased spontaneous and a decreased Con-A-induced blood lymphocyte DNA synthesis. Functional lymphocyte abnormalities were related to advanced clinical stage, high age, mixed cellularity, and lymphocyte depletion histopathology and presence of B symptoms. The 10-year survival of patients in this group was 36%, compared with 62% for the remainder. In a multivariate analysis of the whole series lymphocyte DNA synthesis was besides age the strongest predictor of prognosis. In univariate analyses of the second patient series total lymphocyte, T-cell and subset counts were related to prognosis. These relatively simple lymphocyte functional tests may help to identify young HD patients for whom intensive cytoreductive therapy with or without autologous stem cell support may be the best therapeutic option.     

EMPHYSEMATOUS PYELONEPHRITIS RESPONDING TO MEDICAL THERAPY

We describe two type 2 diabetic patients with unilateral emphysematous pyelonephritis who responded to medical treatment alone. Escherichia coli was isolated in both patients. The presence of gas was confirmed early by ultrasound and CT scan of abdomen. Following treatment, good functional recovery was demonstrable in the affected kidneys by isotope renogram. We stress the need for early diagnosis of this condition and aggressive treatment with broad spectrum antibiotics.