Management of Snakebite

(Australia—Australian Family Physician, December 1997, p. 1386.) Although most snakebites are dramatic, the diagnosis may be missed in patients who are unconscious or severely ill or if the bite occurs in the dark or in heavy vegetation. Presenting symptoms may vary from local discomfort to severe headache, muscle pain, neurologic signs and collapse. The pattern of signs depends on the degree of envenomation. Puncture marks may be difficult to see or may be mistaken for scratches. Severe envenomation is usually indicated by the combination of neurologic abnormalities (such as confusion, ptosis, weakness, paralysis and cardiorespiratory arrest) with evidence of coagulopathy (bleeding and oozing from the wound and dark urine). Rapid enzyme immunoassays are now available to confirm the presence of venom and to identify the most appropriate antivenom. In addition to the laboratory studies necessary to monitor a severely ill patient, clotting studies should be performed and creatinine kinase checked to monitor myolysis, and renal function should be tested. Management of snakebite depends on immediate treatment as soon as a bite is suspected, supportive therapies and appropriate use of antivenom. Current recommendations emphasize immediate pressure immobilization by tight bandaging of the affected limb with immobilization during transport to the hospital. Premedication with a parenteral antihistamine is recommended before antivenom injection.

Usefulness of Cognitive Therapy

(Ireland—Forum, February 1998, p. 48.) Cognitive therapy was developed about 20 years ago and is based on the premise that thoughts (cognition) directly influence feelings. Ingrained negative thoughts, therefore, may contribute to psychologic problems such as depression, panic attacks, phobias and anxiety states. Identifying, acknowledging and replacing such thoughts with more positive and realistic responses to events may contribute significantly to mental health. Initial sessions in cognitive therapy generally focus on establishing an understanding of the concepts with the patient and instructing the patient in the use of a log or diary to record negative feelings and to identify, if possible, the related precipitating event. Follow-up sessions concern the relationship between the precipitant and the negative thoughts and the development of skills to challenge negative thoughts and develop more positive and rational responses. Cognitive therapy has been shown to be more effective than medication in the treatment of depression in primary care and also has been shown to be superior to drug therapy in the management of panic disorders. This type of therapy is a structured and collaborative approach that may be helpful to patients with a wide range of psychologic problems.

Causes of Sudden Loss of Vision

(Australia—Australian Family Physician, March 1998, p. 135.) If sudden vision loss occurs in a patient with a painful red eye, the primary concern is acute angle-closure glaucoma. This condition should be aggressively treated with intravenous acetazolamide and topical timolol to reduce intraocular pressure, and surgery should be considered to prevent recurrence. Vascular causes of vision loss include occlusion of the central retinal artery or vein, macular hemorrhage, vitreous hemorrhage and amaurosis fugax (intermittent disruption of the blood supply caused by emboli or other factors). Retinal detachment typically presents as a shower of floaters or bright flashes followed by defects of the visual field. In papilledema, visual field loss is transient and influenced by head movements. Other conditions of the optic disc, such as optic neuropathy, may cause diminished vision in all or part of the visual field, along with other symptoms.

Management of Phytophotodermatitis

(Canada—Canadian Family Physician, March 1998, pp. 503, 509.) The combination of light and furocoumarins from plant sources may cause a severe dermatitis in susceptible patients. Ultraviolet light activates the naturally occurring furocoumarins that cause phytophotodermatitis, which begins with severe itching followed by the development of edema, erythema and vesiculation. The dermatitis occurs on the area exposed to the plant material and generally appears linear or in bizarre patterns, often on the hands and the forearms. Healing may result in hyperpigmentation. Common plants implicated in phytophotodermatitis are carrots, limes, figs, parsnips, fennel, dill, parsley and bergamot. Since oil of bergamot previously was a common ingredient in perfumes and cosmetics, this dermatitis frequently was seen on the neck, face and hands. Management is based on avoiding the sensitizing agent, careful washing after any exposure and treatment of lesions with wet compresses and topical corticosteroids.