Medical Mystery of the Week

      Match the pictures (A - F) with the following: 1. Skeeter syndrome; 2. Intense muscle spasms; 3. Palatal paralysis; 4. Severe necrosis; 5. Internal bleeding; 6. Myoclonus
      ANSWERS: A-4; B-6; C-5; D-3; E-1; F-2

A   Brown recluse spider                    B  Scorpion 

                                   C  Diamondback rattle snake         D  King cobra 

E   Aedes aegypti mosquito                                         F   Black widow spider  

The Brown Recluse spider (A) is prevalent in south, west and midwest USA; It's venom contains proteases and sphingomyelinase D which are cytotoxic and hemolytic and cause severe pain and rapid tissue necrosis. Scorpions (B) are found on all continents except Antartica and are extant throughout the USA; stings usually cause transient pain and paresthesias, and, occassionally neurologic symptoms such as dysphagia. Stings of Centruroides sculpturative can be fatal. Diamondback rattle snakes (C) are prevalent in southeastern and western USA; they produce a potent mix of hemotoxins, myotoxins, and cytotoxins, and account for most snake bite deaths in the USA. King cobras (D) are found in southern and southeastern Asia; they produce potent neurotoxins and cytotoxins that may cause death within 15-20 minutes of envenomation. The saliva of mosquitos (E) can cause severe local hypersensitivity reactions and fever (Skeeter syndrome); the syndrome is treated with antihistamines and/or steroids. Black widow spiders (F) are found on all continents except antartica; they produce toxins (chiefly alpha-Latrotoxin) that release acetylcholine at neuromuscular junctions causing severe muscle spasms.