Page 177 - LECTURE NOTES
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ª  By causing direct, non-allergic, local tissue damage through stings, bites,

                       exposure of toxic body fluid (blister beetles), and tissue invasion (sand flea and
                       brown recluse spider).

                   ª  By causing allergic reactions to their secretions, skins, or scales.
                   ª  By producing systemic toxicity, such as that caused by neurotoxin release (black

                       widow spider and scorpions).
                   ª  By transmitting diseases.



              7.12.7.1 Scabies

               Scabies is one of such arthropod associated  diseases by the mite, Sarcoptes scabei

               varhominis, and characterized by marked itching.

               Scabies is a contagious complaint, which is transmitted only by close contact. It is

               therefore a family disease spreading amongst those living in close association,
               especially when they sleep together in the same bed.


               7.12.7.2 Prevention and control of scabies



               All cases of scabies can be cured; there are no resistant infections. Methods aimed at
               killing the mites will do little to immediately alleviate the nuisance and irritation caused

               by the rash, although this will eventually disappear. Separate medical treatment
               however, may be necessary especially  if secondary infections have become

               established. In the past, a common procedure was to give the patient a hot bath and a

               vigorous scrubbing with a brush until the patient bled, but this is not very effective at
               either removing or killing the mites. However, as many but certainly not all, patients with

               scabies are dirty, an ordinary bath before  treatment may be advisable for general
               hygienic reasons. However, if large numbers of patients suffering from scabies are to be

               treated, such as in epidemic situations, bathing may not be practical.



               Decreasing the humidity in rooms, improving ventilation and removing dust can control
               mites and associated fungi. Bedrooms and living rooms should be aired regularly, or

               other measures should be taken to reduce dampness. The shaking of bedclothes and

               frequent washing of sheets and blankets reduces the availability of food and therefore

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