QJM : monthly journal of the Association of Physicians
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In origin, itch can be cutaneous ("pruritoceptive", e.g. dermatitis), neuropathic (e.g. multiple sclerosis), neurogenic (e.g. cholestasis), mixed (e.g. uraemia) or psychogenic. Although itch of cutaneous origin shares a common neural pathway with pain, the afferent C-fibres subserving this type of itch are a functionally distinct subset: they respond to histamine, acetylcholine and other pruritogens, but are insensitive to mechanical stimuli. Histamine is the main mediator for itch in insect bite reactions and in most forms of urticaria, and in these circumstances the itch responds well to H(1)-antihistamines. ⋯ Other drug treatments for itch include rifampicin, colestyramine and 17-alpha alkyl androgens (cholestasis), thalidomide (uraemia), cimetidine and corticosteroids (Hodgkin's lymphoma), paroxetine (paraneoplastic itch), aspirin and paroxetine (polycythaemia vera) and indometacin (some HIV+ patients). If the remedies specified fail, paroxetine and mirtazapine should be considered. Ultraviolet B therapy, particularly narrow-band UVB, may be superior to drug treatment for itch in uraemia.
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The Glasgow Coma Scale (GCS) is widely used in assessing level of consciousness. The GCS verbal component may be misleading in acute stroke: a focal neurological deficit leading to dysphasia could affect the score, independently of level of consciousness. ⋯ The GCS contains valuable predictive information. Regardless of whether dysphasia is present, the verbal score should be assessed since it adds prognostic information to that from the eye component, and has greater value than the motor score.